CN101166072B - Mimo wlan systems - Google Patents

Abstract

A multiple-access MIMO WLAN system that employs MIMO, OFDM, and TDD. The system (1) uses a channel structure with a number of configurable transport channels, (2) supports multiple rates and transmission modes, which are configurable based on channel conditions and user terminal capabilities, (3) employs a pilot structure with several types of pilot (e.g., beacon, MIMO, steered reference, and carrier pilots) for different functions, (4) implements rate, timing, and power control loops for proper system operation, and (5) employs random access for system access by the user terminals, fast acknowledgment, and quick resource assignments. Calibration may be performed to account for differences in the frequency responses of transmit/receive chains at the access point and user terminals. The spatial processing may then be simplified by taking advantage of the reciprocal nature of the downlink and uplink and the calibration.

Description

MIMO wlan system

The application be the applying date be on October 24th, 2003 application number be the divisional application of No. 200380104560.1 denomination of invention Chinese patent application that is " MIMO wlan system ".

Require priority according to 35 U.S.C. § 119

The application requires the 60/421st, the priority of No. 309 U.S. Provisional Patent Application, and the latter is entitled as " MIMOWLAN system ", submits on October 25th, 2002.

Background

Technical field

The present invention relates generally to data communication, relate in particular to a multiple-input and multiple-output (MIMO) WLAN (wireless local area network) (WLAN) communication system.

Background technology

Wireless communication system is widely used for providing such as the various types of communication such as voice, grouped data.These systems can be can by share that available system resource is supported sequentially or simultaneously with the multi-address system of multiple telex networks.The example of multi-address system comprises code division multiple access (CDMA) system, time division multiple access (TDMA) system and frequency division multiple access (FDMA) system.

WLAN (wireless local area network) (WLAN) is also widely used in the communication for example allowing via wireless link, between radio-based electronic devices (computer).WLAN can adopt the access point (or base station) of working as hub, and provides connection for wireless device.Access point also can be linked WLAN (or " bridge joint ") wired lan, thereby makes wireless device can access LAN resource.

In wireless communication system, can arrive receiver unit by multiple propagation paths from radio frequency (RF) modulated signal of transmitter unit.Due to the factors such as such as decline and multipath, the feature of propagation path can change along with the time.In order to provide with respect to the diversity of severe path effects and to improve performance, can use many and transmit and receive antenna.If the propagation path transmitting and receiving between antenna is Line independent (i.e. transmission on a paths is not the combination of transmitting on other paths), this sets up at least to a certain extent,, along with the increase of antenna amount, the probability that correctly receives transfer of data also improves.Generally speaking, along with transmitting and receiving the increase of antenna amount, diversity also increases, and performance is also improved.

Mimo system adopts many (N _t) transmitting antenna and Duo Gen (N _r) reception antenna carries out transfer of data.By N _ttransmit antennas and N _rthe mimo channel that root reception antenna forms can be broken down into N _sindividual space channel, N _s≤ min{N _t, N _r.N _seach of individual space channel is corresponding to a dimension.If use many to transmit and receive the additional dimension that antenna creates, mimo system just can provide improved performance (transmission capacity for example having improved and/or higher reliability).

The resource of one given communication system is generally subject to various regulations constraints and other actual Considerations are limit.But, may require system to support multiple terminals, various services are provided, realize specific performance objective etc.

Therefore the MIMO wlan system that, needs to support multiple users in this area and high systematic function is provided.

Summary of the invention

Here having described one has various abilities and can realize high performance multiple access MIMO wlan system.In one embodiment, system adopts MIMO and OFDM (OFDM) keep high-throughput, path effects to degeneration and other benefits are provided.Each access point in system can be supported multiple user terminals.The resource of down link and up link is distributed the requirement, channel condition and the other factors that depend on user terminal.

The channel architecture of supporting effective down link and ul transmissions is also provided here.Channel architecture comprises the multiple transmission channels that can be used for multiple functions, signaling, down link and the uplink data transmission that described multiple function ratio are distributed as system parameters and resource, random access of system etc.The various attributes of these transmission channels are configurable, and this makes easily channel and the loading condition of Adaptive change of system.

MIMO wlan system supports multiple speed and transmission mode to maintain high-throughput in the time of channel condition and ability of user terminal support.Speed can be based on channel condition estimation and configure, and can be that down link and up link are independently selected.Also can use different transmission modes, this depends on number of antennas and the channel condition at user terminal place.Each transmission mode is associated with the different spaces processing at transmitter and receiver place, and can be selected under different conditions of work and use.For higher throughput and/or diversity, spatial manipulation is convenient to from the transfer of data of many transmit antennas and/or with the data receiver of many reception antennas.

In one embodiment, MIMO wlan system is that down link and up link are used single frequency band, and down link and up link are used time division duplex (TDD) to share same working band.For TDD system, down link and uplink channel responses are reciprocal.Here provide collimation technique to determine and make up the difference of frequency response of access point and user terminal place transmit/receive chains.The reciprocal characteristic of utilizing down link and up link and the technology of calibrating the spatial manipulation of simplifying access point and user terminal place have also been described here.

The pilot configuration with difference in functionality a few class pilot tones used is also provided.For example, can be that frequency and system acquisition use beacon pilot frequency, can use MIMO pilot tone for channel estimating, can use controlled index (being controlled pilot tone) for improved channel estimating, and can use carrier pilot for Phase Tracking.

Various control loops for correct system operation are also provided.Can in down link and up link, carry out independently speed control.Can be that power control is carried out in specific transmission (service of for example fixed rate).Can make up for ul transmissions the different propagation delays of residing user terminal in system by timing controlled.

The random access technology that makes user terminal energy connecting system is also provided.Access, the quick confirmation of system access trial and the fast allocation of downlink/uplink resource of the multiple user terminals of these technical supports to system.

Various aspects of the present invention and embodiment are described in further detail below.

Brief description of the drawings

In the detailed description proposing by reference to the accompanying drawings below, feature of the present invention and character will become more apparent, and in accompanying drawing, identical reference number represents identical element, wherein:

Fig. 1 illustrates a MIMO wlan system;

Fig. 2 illustrates the layer structure of MIMO wlan system;

Fig. 3 A, 3B and 3C illustrate respectively TDD-TDM frame structure, FDD-TDM frame structure and FDD-CDM frame structure;

Fig. 4 is shown with the TDD-TDM frame structure of five transmission channel-BCH, FCCH, FCH, RCH and RACH;

Fig. 5 A illustrates variety of protocol data cell (PDU) form of five transmission channels to 5G;

Fig. 6 illustrates a kind of structure of FCH/RCH grouping;

Fig. 7 illustrates an access point and two user terminals;

Fig. 8 A, 9A and 10A illustrate three transmitter units that are respectively used to diversity mode, space multiplexing mode and wave beam control model;

Fig. 8 B, 9B and 10B illustrate three transmit diversity processors that are respectively used to diversity mode, space multiplexing mode and wave beam control model;

Fig. 8 C illustrates an OFDM modulator;

Fig. 8 D illustrates an OFDM code element;

Figure 11 A illustrates framing unit and the disarrangement device in transmit data processor;

Figure 11 B illustrates encoder and the repetition/brachymemma unit in transmit data processor;

Figure 11 C illustrates another transmit data processor that can be used for space multiplexing mode;

Figure 12 A and 12B illustrate the state diagram for user terminal operations;

Figure 13 illustrates the timeline of RACH;

Figure 14 A and 14B illustrate the process that is respectively used to the transmission rate of controlling down link and up link;

Figure 15 illustrates the operation of power control circuit; And

Figure 16 illustrates the process of the up link sequential for regulating user terminal.

Describe in detail

Here use word " exemplary " to mean " serving as example, example or explanation ".Here any embodiment that is described as " exemplary " needn't be regarded as more more preferred or favourable than other embodiment or design.

1. total system

I. total system

Fig. 1 illustrates the MIMO wlan system 100 of supporting multiple users and realizing various aspects embodiment of the present invention.MIMO wlan system 100 comprises multiple access points (AP) 110 of the communication of supporting multiple user terminals.For simplicity, two access points 110 are only shown in Fig. 1.Access point is generally the fixed station for communicating with user terminal.Access point also can be called base station or some other term.

User terminal 120 can spread in system.Each user terminal can be the fixing or mobile terminal that can communicate by letter with access point.User terminal also can be called mobile radio station, distant station, accesses terminal, subscriber equipment (UE), wireless device or some other term.Each user terminal can may communicate by multiple access points with one at arbitrary given time in down link and/or up link.Down link (being forward link) refers to the transmission from access point to user terminal, and up link (being reverse link) refers to the transmission from user terminal to access point.

In Fig. 1, access point 110a communicates by letter with user terminal 120a by 120f, and access point 110b communicates by letter with user terminal 120f by 120k.According to the particular design of system 100, simultaneously (for example, by multiple encoding channels or subchannel) or sequentially (for example, via multiple time slots) and multiple user terminals communicate of access point.In arbitrary given moment, user terminal can receive the downlink transmission from one or more access points.From the downlink transmission of each access point can comprise will by overhead data that multiple user terminal received, will be by the customer-specific data that specific user terminal received, the data of other type or their arbitrary combination.Overhead data can comprise pilot tone, paging and broadcast, system parameters etc.

MIMO wlan system is based on a central authoritiesization controller network structure.Like this, system controller 130 is coupled to access point 110, is further coupled to other System and Network.For example, system controller 130 can be coupled to packet data network (PDN), cable LAN (LAN), wide area network (WAN), the Internet, public switch telephone network (PSTN), cellular communications network etc.System controller 130 can be designed to multiple functions, such as (1) to coordination and the control of the access point of its coupling, (2) route data between these access points, (3) access with control communicating by letter of the user terminal of serving with these access points, etc.

Compared with conventional wlan system, perhaps MIMO wlan system can provide covering power much bigger high-throughput.MIMO wlan system can be supported synchronous, asynchronous with etc. time data/voice service.MIMO wlan system can be designed to provide following characteristics:

High service reliability

Guaranteed service quality (QoS)

High instantaneous data rates

Spectral efficient

The coverage of expansion.

MIMO wlan system for example can be operated in, in each frequency band (2.4GHz and 5.xGHz U-NII frequency band), is subject to the bandwidth special for selected working band and radiation limitations.System is designed to support the use of indoor and outdoors, and general maximum cell size is 1km or still less.The terminal applies that system support is fixing, but a few thing pattern is also supported portable and limited move operation.

1.MIMO, MISO and SIMO

In certain embodiments, and as described in this specification, each access point is equipped with four and transmits and receives antenna and carry out data input and data output, wherein carrys out sending and receiving with four identical antennas.The also transmitting antenna of support equipment (for example access point, user terminal) and the situation that reception antenna is not shared of system, even if this configuration provides lower performance while conventionally sharing than antenna.MIMO wlan system can also design like this: make each access point be equipped with the transmit/receive antenna of some other quantity.Each user terminal can be equipped with single transmit/receive antenna or many transmit/receive antennas carry out data input and data output.The antenna amount that each type of user terminal adopts depends on various factors, the service supported such as user terminal (for example voice, data or both), cost consideration, regulations constraint, safety problem etc.

For given one-to-many antenna access point and many antennas user terminal, mimo channel is by the N that can be used for transfer of data _ttransmit antennas and N _rroot reception antenna forms.Between access point and different many antennas user terminal, form different mimo channels.Each mimo channel can be broken down into N _sindividual space channel, N _s≤ min{N _t, N _r.N _sindividual data flow can be at N _son individual space channel, be sent out.Require spatial manipulation at receiver place, may or may not carry out spatial manipulation at transmitter place so that at N _son individual space channel, launch multiple data flow.

N _sindividual space channel possibility is orthogonal or possibility is non-orthogonal.This depends on various factors, and such as whether (1) carries out spatial manipulation for obtaining orthogonal spatial channels at transmitter place, and (2) whether at transmitter and receiver, both locate to carry out spatial manipulation in the time making space channel orthogonalization.If do not carry out spatial manipulation, N at transmitter place _sindividual space channel can be used N _stransmit antennas is carried out, and can not be orthogonal.

As described below, decompose N by the channel response matrix to mimo channel _sindividual space channel can be orthogonal.If N _sindividual space channel uses and decomposes and orthogonal, and each space channel is called the eigenmodes of mimo channel, decomposes the spatial manipulation that requires transmitter and receiver place.In this case, N _sindividual data flow can be at N _sorthogonal transmission in individual eigenmodes.But eigenmodes generally refers to theoretical construct.Due to a variety of causes, N _sindividual space channel is not generally completely orthogonal.For example, if (1) transmitter is known mimo channel, or (2) transmitter and/or receiver have the incomplete estimation of mimo channel, and space channel can be not orthogonal.For simplicity, in the following description, term " eigenmodes " is used for representing to attempt to make the orthogonalized situation of space channel with decomposing, even if attempt because incomplete channel estimating etc. is former thereby not exclusively successful.

Antenna for access point place for example, to determined number (four), each user terminal can with number of spatial channels depend on the number of antennas that user terminal adopts and the feature of the Technique of Wireless MIMO Channel of be coupled access point antenna and user terminal antenna.If user terminal is equipped with an antenna, the single antenna at four of access point place antennas and user terminal place has formed the single delivery channel of many inputs (MISO) of down link and single input multiple-output channel (SIMO) of up link.

MIMO wlan system can be designed to support multiple transmission mode.Table 1 is listed the transmission mode of being supported by the exemplary design of MIMOWLAN system.

Table 1

For simplicity, term " diversity " refers to transmission diversity in the following description, unless specialized.

The down link of each user terminal and up link can with transmission mode depend on user terminal place adopt number of antennas.Table 2 is listed the transmission mode that the different terminals type of down link and up link can be used, and supposes and has many (for example four) antennas at access point place.

Table 2

For down link, all transmission modes except space multiplexing mode all can be used for single antenna user terminal, and all transmission modes all can be used for many antennas user terminal.For up link, all transmission modes can be used by many antennas user terminal, and single antenna user terminal uses MIMO pattern to send data from an available antenna.Receive diversity (receiving transfer of data with many reception antennas) can be used for SIMO, diversity and wave beam control model.

MIMO wlan system also can be designed to support various other transmission modes, and this within the scope of the invention.For example, beam forming pattern can be used to send data in single eigenmodes, has used the amplitude of this eigenmodes and phase information (instead of only use phase information, the latter be that wave beam control model is all used).For another example, can define one " uncontrolled " space multiplexing mode, wherein transmitter only sends multiple data flow (not carrying out any spatial manipulation) from many transmit antennas, and necessary spatial manipulation carried out by receiver so that the data flow that isolation and recovery send from many transmit antennas.For also having an example, can define one " multi-user " space multiplexing mode, wherein access point sends to multiple user terminals (by spatial manipulation) from many transmit antennas multiple data flow concurrently in up link.For there being again an example, can define a kind of space multiplexing mode, wherein transmitter is carried out spatial manipulation to attempt that the multiple data flow that send on many transmit antennas are carried out to orthogonalization (but may be not exclusively successful due to incomplete channel estimating), and receiver is carried out requisite space processing and isolated and recover from the data flow of many transmit antennas transmissions.Like this, for the spatial manipulation of carrying out via the multiple data flow of many radical spaces channels transmit can carried out with upper/lower positions: (1) is at both places of transmitter and receiver, (2) only at receiver place, or (3) are only at transmitter place.Can use different spatial reuses according to following factor, the ability of for example access point and user terminal, available channel condition information, system requirements etc.

Conventionally, access point and user terminal can be designed to any amount of transmitting antenna and reception antenna.For simplicity, be described below specific embodiment and design, wherein each access point is equipped with four transmit/receive antennas, and each user terminal is equipped with four or less transmit/receive antenna.

2.OFDM

In one embodiment, MIMO wlan system adopts OFDM that total system bandwidth is divided into multiple (N effectively _f) orthogonal subbands.These subbands also can be called as tone, frequency band or frequency channels.According to OFDM, each subband is associated with corresponding subcarrier, and subcarrier can be modulated by data.For using the mimo system of OFDM, each space channel of each subband can be regarded as a transmission channel independently, and the complex gain being associated with each subband is whereby constant in subband bandwidth.

In one embodiment, to be divided into 64 orthogonal subbands (be N to system bandwidth _f=64), be assigned to index-32 to+31.In these 64 subbands, for data use 48 subbands (for example index is ± 1 ...; 6,8 ...; 20; 22 ..., 26}); for pilot tone and possible signaling use 4 subbands (for example index is ± { 7; 21}), DC subband (index is 0) does not use, and the subband of adventure does not use yet and serves as protection subband.This OFDM sub band structure is described in further detail in the document of ieee standard 802.11a, the document is entitled as " Part 11:Wireless LAN Medium Access Control (MAC) and Physical Layer (PHY) Specifications:High-Speed Physical Layer in the 5GHz Band; " propose in September, 1999, it can obtain for the public, and incorporated herein by reference.Subband and various other OFDM sub band structure that also can use varying number for MIMO wlan system, this within the scope of the invention.For example, can make for transfer of data whole 53 indexes of index of reference from-26 to+26.For another example, can use 128 subbands structure, 256 subbands structure and there is the sub band structure of some other numbers of sub-band.For clear, the MIMO wlan system with above-mentioned 64 sub band structure is described below.

For OFDM, first the data that send on each subband modulate (being symbol mapped) by a certain modulation schemes of selecting for this subband.For untapped subband provides null value.For each code-element period, all N _fthe modulated symbol of individual subband and null value all use invert fast fourier transformation (IFFT) to transform to time domain, comprise N to obtain _fthe conversion code element of individual time-domain sampling.Eachly convert the duration of code element and the bandwidth of each subband is inversely related.In a particular design of MIMO wlan system, system bandwidth is 20MHz, N _f=64, the bandwidth of each subband is 312.5KHz, and each duration that has converted code element is 3.2 microseconds.

OFDM can provide specific advantage, such as the ability of contrary frequency selectivity decline, it is characterized in that there is different channel gains at the different frequency place of total system bandwidth.Be well known that, frequency selective fading causes the interference (ISI) between code element, and ISI is that the each code element receiving in signal is served as a kind of phenomenon of the interference of middle subsequent symbol to received signal.The ability that ISI distortion is correctly decoded receiving symbol by impact makes performance degradation.Form corresponding OFDM code element by repeating each part (or adhering to a Cyclic Prefix to it) that has converted code element, can easily tackle frequency selective fading with OFDM, corresponding OFDM code element is sent out subsequently.

The length (amount that will repeat) of the Cyclic Prefix of each OFDM code element depends on the delay expansion of wireless channel.Particularly, in order effectively to resist ISI, it is long that Cyclic Prefix should postpone expansion than the greatest expected of system.

In one embodiment, can use for OFDM code element the Cyclic Prefix of different length, this depends on the delay expansion of expection.For above-mentioned specific MIMO wlan system, can select for 400 nanoseconds for OFDM code element the Cyclic Prefix of (8 samplings) or 800 nanoseconds (16 samplings)." short " OFDM code element is used the Cyclic Prefix of 400 nanoseconds, and the duration is 3.6 microseconds." length " OFDM code element is used the Cyclic Prefix of 800 nanoseconds, and the duration is 4.0 microseconds.If the delay of greatest expected expansion was less than or equal to for 400 nanoseconds, can use short OFDM code element, be greater than for 400 nanoseconds if postpone expansion, can use long OFDM code element.Can select different Cyclic Prefix for different transmission channels, Cyclic Prefix also can dynamically be selected, as described below.By may time use shorter Cyclic Prefix can realize higher throughput of system because can send shorter OFDM code element of more durations in a given Fixed Time Interval.

MIMO wlan system can be designed to not use OFDM, and this within the scope of the invention.

3. layer structure

Fig. 2 has illustrated the layer structure 200 that can be used for MIMO wlan system.Layer structure 200 comprises: (1) is approximate corresponding to the 3rd layer of ISO/OSI reference model and with application and the higher level protocol of upper strata (higher level), (2) corresponding to agreement and the service of the 2nd layer (link layer), and (3) are corresponding to agreement and the service of the 1st layer (physical layer).

Higher level comprises various application and agreement, such as signaling service 212, data, services 214, voice service 216, circuit data applications etc.Signaling is generally provided as message, and data are generally provided as grouping.Service in higher level and application start and termination messages and grouping according to the meaning of one's words of communication protocol between access point and user terminal and sequential.The 2nd layer of service providing is provided higher level.

Support the message that generates of higher level and the transmission of grouping for the 2nd layer.In the embodiment shown in Figure 2, the 2nd layer comprises link access control (LAC) sublayer 220 and medium access control (MAC) sublayer 230.LAC has realized sublayer a SDL, and the message that higher level generates can correctly be transmitted and transmit to this agreement.Media access control sublayer and the 1st layer of service providing are provided in LAC sublayer.Media access control sublayer is responsible for coming message transfer and grouping with the 1st layer of service providing.The access of application and service in media access control sublayer control RLP higher level processed to the 1st layer of resource.Media access control sublayer can comprise radio link protocol (232), and this agreement is used to grouped data provides the retransmission mechanism of higher reliability.The 2nd layer provides protocol Data Unit (PDU) to the 1st layer.

The 1st layer of sending and receiving that comprises physical layer 240 and support wireless signal between access point and user terminal.Physical layer is carried out for each transmission channel and is encoded, interweaves, modulation and spatial manipulation, and described transmission channel is used for sending message and the grouping that higher level generates.In this embodiment, physical layer comprises a multiplex sublayer 242, and multiplex sublayer 242 is being multiplexed into correct frame format for the PDU of each transmission channel processing.The 1st layer provides data taking frame as unit.

Fig. 2 illustrates the specific embodiment of the layer structure that can be used for MIMO wlan system.Can also be MIMOWLAN system and various other the suitable layer structures of use, this within the scope of the invention.Every layer of performed function is described in further detail below.

4. transmission channel

Multiple services and application can be supported by MIMO wlan system.In addition, correct system operates other required data and may be sent and be exchanged between access point and user terminal by access point.Can define multiple transmission channels to transmit Various types of data for MIMO wlan system.Table 3 is listed one group of exemplary transmission channel, and the concise and to the point description of each transmission channel is also provided.

Table 3

As shown in table 3, the downlink transmission channel that access point uses comprises BCH, FCCH and FCH.The uplink transmission channels that user terminal uses comprises RACH and RCH.Each of these transmission channels is described in further detail below.

The transmission channel of listing in table 3 has represented a specific embodiment of the channel architecture that can be used for MIMO wlan system.The use that can be also MIMO wlan system defines less, additional and/or different transmission channel.For example, specific function can for example, be supported by the special transmission channel of function (pilot tone, paging, power control and synchronizing channel).Like this, can and use other channel architecture with different transmission channel groups for the definition of MIMO wlan system, this within the scope of the invention.

5. frame structure

Can define multiple frame structures for transmission channel.The particular frame structure that is used for MIMO wlan system depends on various factors, and such as (1) is that down link and up link are used identical or different frequency bands, and (2) are for multiplexing transmission channel multiplexing scheme together.

If only there is a frequency band to use, can use time division duplex (TDD) in the out of phase of a frame, to send down link and up link, as described below.If there are two frequency bands to use, use Frequency Division Duplexing (FDD) (FDD) on different frequency bands, to send down link and up link.

For TDD and FDD, transmission channel can be multiplexed in together with time division multiplexing (TDM), code division multiplexing (CDM), frequency division multiplexing (FDM) etc.For TDM, each transmission channel is assigned to a different piece of a frame.For CDM, transmission channel is sent out concurrently, but each transmission channel carrys out channelizing by a different channelization code, is similar to the channelizing of carrying out in code division multiple access (CDMA) system.For FDM, each transmission channel is assigned to a different piece of link frequency bands.

Table 4 is listed the various frame structures that can be used to transmit transmission channel.Each of these frame structures is described in further detail below.For clear, for this group transmission channel of listing in table 3 has been described frame structure.

Table 4

Fig. 3 A has illustrated the embodiment of a TDD-TDM frame structure 300a, and this structure can be used in the time using single frequency band for down link and up link.Transfer of data occurs taking tdd frame as unit.Each tdd frame can be defined as striding across a special time duration.The frame duration can be selected based on various factors, for example bandwidth of (1) working band, desired size of the PDU of (2) transmission channel etc.Conventionally, the shorter frame duration can provide the delay of minimizing.But the longer frame duration may be more effective, because header and expense can represent the smaller portions of a frame.In a specific embodiment, the duration of each tdd frame is 2 milliseconds.

Each tdd frame is divided into down link phase place and up link phase place.For three downlink transmission channel-BCH, FCCH and FCH, down link phase place is further divided into three segmentations.For two uplink transmission channels-RCH and RACH, up link phase place is further divided into two segmentations.

The fixing duration that the segmentation of each transmission channel can be defined as changing frame by frame or variable duration.In one embodiment, BCH segmentation has been defined as a fixing duration, and FCCH, FCH, RCH and RACH segmentation have been defined as the variable duration.

The segmentation of each transmission channel can be used to transmit the one or more protocol Data Units (PDU) for this transmission channel.In the specific embodiment shown in Fig. 3 A, in down link phase place, BCH PDU is sent out in the first segmentation 310, and FCCH PDU is sent out in the second segmentation 320, and one or more FCH PDU are sent out in the 3rd segmentation 330.In up link phase place, one or more RCH PDU are sent out in the 4th segmentation 340, and one or more RACH PDU are sent out in the 5th segmentation 350 of tdd frame.

Frame structure 300a represents the particular topology of each transmission channel in a tdd frame.This layout can provide specific benefit for the transfer of data in down link and up link, such as the delay reducing.First BCH is sent out in tdd frame, because he transmits the system parameters that can be used for the PDU of other transmission channel in same tdd frame.FCCH is then sent out, because its transmission channel assignment information, described channel allocation information is illustrated in has specified receive the down link data on FCH in current tdd frame and has specified which user terminal to receive the uplink data on RCH for which user terminal.Also can and use other TDD-TDM frame structure for the definition of MIMO wlan system, this within the scope of the invention.

Fig. 3 B has illustrated the embodiment of the FDD-TDM frame structure 300b that may use in the time using two frequency bands that separate to send down link and up link.Down link data is sent out in descending chain circuit frame 302a, and uplink data is sent out in uplink frame 302b.Each down link and uplink frame can be defined the specific time remaining phase (for example 2 milliseconds) that strides across.For simplicity, down link and uplink frame can be defined as the identical duration, and are further defined on frame boundaries and align.But, can be also (i.e. skew) frame boundaries that down link and up link are used different frame durations and/or non-alignment.

As shown in Figure 3 B, for three downlink transmission channel, descending chain circuit frame is divided into three segmentations.For two uplink transmission channels, uplink frame is divided into two segmentations.The segmentation of each transmission channel can be defined as the fixing or variable duration, and can be used for transmitting one or more PDU for this transmission channel.

In the specific embodiment shown in Fig. 3 B, descending chain circuit frame transmits respectively a BCH PDU, a FCCH PDU and one or more FCH PDU in segmentation 310,320 and 330.Uplink frame transmits respectively one or more RCH PDU and one or more RACH PDU in segmentation 340 and 350.This particular topology can provide the above-mentioned benefit delay of the minimizing of transfer of data (for example for).As described below, transmission channel may have different PDU forms.The FDD-TDM frame structure that also can define and use for MIMO wlan system other, this within the scope of the invention.

Fig. 3 C has illustrated in the time that down link and up link are used frequency band separately to send the also embodiment of operable FDD-CDM/FDM frame structure 300c.Down link data can be sent out in descending chain circuit frame 304a, and uplink data can be sent out in uplink frame 304b.Down link and uplink frame can be defined as the identical duration (for example 2 milliseconds) and align at frame boundaries place.

As shown in Figure 3 C, in descending chain circuit frame, send concurrently three downlink transmission channel, in uplink frame, send concurrently two uplink transmission channels.For CDM, the transmission channel of each link comes " channelizing " by different channelization code, and described channelization code can be Walsh code, orthogonal variable spreading factor (OVSF) code, class orthogonal function (QOF) etc.For FDM, the transmission channel of each link is assigned to the different piece of this link frequency bands.Also can be the transmitted power of the different transmission channels use varying numbers in each link.

Also can be for down link and uplink transmission channels use other frame structure, this is within the scope of the invention.In addition, may use dissimilar frame structure for down link and up link.For example, can use the frame structure based on TDM for down link, and use the frame structure based on CDM for up link.

In the following description, suppose that MIMO wlan system is that down link and ul transmissions are used a frequency band.For clear, the TDD-TDM frame structure shown in Fig. 3 A is for MIMO wlan system.For clear, the specific implementation of TDD-TDM frame structure is described in this manual.For this realization, the duration of each tdd frame is fixed to 2 milliseconds, and the OFDM number of symbols of every tdd frame is the function of OFDM code element paging prefix length used.The fixing duration of BCH is 80 microseconds, and uses the paging prefixes of 800 nanoseconds for launched OFDM code element.If use the paging prefixes of 800 nanoseconds, the remainder of tdd frame comprises 480 code elements, if use the Cyclic Prefix of 400 nanoseconds, the remainder of tdd frame comprises 533 OFDM code elements and add the excessive time of 1.2 microseconds.This excessive time can be added to protection interval in the end of RACH segmentation.Also can use other frame structure and other realization, this within the scope of the invention.

II. transmission channel

Transmission channel is used for sending Various types of data, and can be classified as two groups: Common transport channel and dedicated transmission channel.Owing to having used public and dedicated transmission channel for different objects, therefore can use different processing for these two groups of transmission channels, be described in further detail as follows.

Common transport channel.Common transport channel comprises BCH, FCCH and RACH.These transmission channels are used for data to send to multiple user terminals or receive data from multiple user terminals.For improved reliability, BCH and FCCH are sent with diversity mode by access point.In up link, RACH is sent by wave beam control model (if user terminal support) by user terminal.BCH, with known fixed rate work, can need not any additional information receive and treatments B CH user terminal.FCCH and RACH support multiple speed to allow higher efficiency.As used herein, each " speed " or " rate set " are associated with a specific code rate (or encoding scheme) and a specific modulation scheme.

Dedicated transmission channel.Dedicated transmission channel comprises FCH and RCH.These transmission channels are commonly used to customer-specific data to send to specific user terminal.As required with according to available situation, FCH and RCH can be dynamically allocated to user terminal.FCH can also be used for an expense, paging and broadcast and send to user terminal in broadcast mode.Conventionally, before the arbitrary customer-specific data on FCH, send expense, paging and broadcast.

Fig. 4 has illustrated the exemplary transmission on BCH, FCCH, FCH, RCH and RACH based on TDD-TDM frame structure 300a.In this embodiment, a BCH PDU 410 and a FCCH PDU 420 are sent out respectively in BCH segmentation 310 and FCCH segmentation 320.FCH segmentation 330 can be used for sending one or more FCH PDU 430, and each FCH PDU 430 can point to a specific user terminal or multiple user terminal.Similarly, one or more RCH PDU 440 can be sent out by one or more user terminals in RCH segmentation 340.The beginning of each FCH/RCH PDU is offset to represent by the FCH/RCH from last segmentation finishes.RACH PDU 450 can in RACH segmentation 350, be sent by multiple user terminals so that connecting system and/or send SMS message is as described below.

For clear, for the specific T DD-TDM frame structure shown in Fig. 3 A and 4 has been described transmission channel.

1. broadcast channel (BCH)-down link

Access point uses BCH that beacon pilot frequency, MIMO pilot tone and system parameters are sent to user terminal.User terminal comes capture systems sequential and frequency with beacon pilot frequency.User terminal is estimated the mimo channel being formed by the antenna of access point antenna and they self by MIMO pilot tone.Be described in further detail beacon pilot frequency and MIMO pilot tone below.System parameters has been specified each attribute of down link and ul transmissions.For example, because the duration of FCCH, FCH, RACH and RCH segmentation is variable, in BCH, be sent as current tdd frame and specify the system parameters of the length of each in these segmentations.

Fig. 5 A has illustrated the embodiment of BCH PDU 410.In this embodiment, BCH PDU 410 comprises leader part 510 and message part 516.Leader part 512 also comprises beacon pilot frequency part 512 and MIMO pilot portion 514.Part 512 transmits beacon pilot frequency, and the fixing duration is TCP=8 microsecond.Part 514 transmits MIMO pilot tone, and the fixing duration is TMP=32 microsecond.Part 516 transmits BCH message, and the fixing duration is TBM=40 microsecond.The duration of BCH PDU is fixed on TCP+TMP+TBM=80 microsecond.

Leader can be used for sending pilot tone and/or the out of Memory of a class or multiclass.Beacon pilot frequency comprises the one group of specific modulated symbol sending from whole transmitting antennas.MIMO pilot tone comprises with the different orthogonal one group of specific modulated symbol sending from whole transmitting antennas of encoding, makes to receive the pilot tone that functional recovery sends from every antenna.For beacon and MIMO pilot tone can be used not modulated symbol on the same group.The generation of beacon and MIMO pilot tone is described in further detail below.

BCH message transfer service configuration information.Table 5 has been listed each field of an exemplary BCH message message format.

Table 5-BCH message

Frame counter can be used to each process (for example pilot tone, scrambler, overlay code etc.) at synchronous access point and user terminal place.Frame counter can be realized by 4 bit counter of wraparound.This counter increases one in the time of the beginning of each tdd frame, and Counter Value is included in frame counter field.Network ID field has represented the identifier (ID) of access point belonging network.AP id field has represented the ID of access point in network ID.AP Tx Lvl and AP Rx Lvl field have represented respectively the maximum transit power level at access point place and the received power level of expectation.User terminal can be determined initial uplink transmitted power with the received power level of expecting.

FCCH length, FCH length and RCH length field have represented respectively FCCH, the FCH of current tdd frame and the length of RCH field.The length of these fields provides taking OFDM code element as unit.The OFDM code element duration of BCH is fixed on 4.0 microseconds.The OFDM code element duration of all other transmission channels (being FCCH, FCH, RACH and RCH) is all variable, and depends on selected Cyclic Prefix, and Cyclic Prefix is specified by Cyclic Prefix duration field.FCCH speed field has represented the speed that the FCCH of current tdd frame uses.

RACH length field has represented the length of RACH field, and it provides taking RACH time slot as unit.The duration of each RACH time slot is provided by RACH time slot size field, and unit is OFDM code element.RACH protection interval field has represented the time quantum of the BCH segmentation of a upper RACH time slot and next tdd frame between starting.Each field of this of RACH is described in further detail below.

Paging bit and broadcast bit have represented in current tdd frame, on FCH, whether to have sent respectively beep-page message and broadcast.These two bits can be arranged independently for tdd frame.Before RACH acknowledgement bit has represented to send tdd frame on FCCH in current tdd frame, on RACH, whether send to PDU really with.

Crc field comprises the crc value of whole BCH message.This crc value can be used for determining that the BCH message receiving is by correctly decoding (being) or by decoding (being wiped free of) mistakenly by user terminal.Tail bit field comprises one group of null value, and this group null value is used for, in the end of BCH message, convolution coder is reset to known state.

As shown in table 5, BCH message comprises 120 bits altogether.By using the processing of describing in detail below, these 120 bits can be sent out together with 10 OFDM code elements.

Table 5 illustrates a specific embodiment of the form of BCH message.Can also define and use other BCH message format with less, additional and/or different field, this within the scope of the invention.

2. forward control channel (FCCH)-down link

In one embodiment, access point can frame by frame be FCH and RCH Resources allocation.Access point passes on the resource of FCH and RCH to distribute (being channel allocation) with FCCH.

Fig. 5 B has illustrated an embodiment of FCCH PDU 420.In this embodiment, FCCH PDU only comprises the part 520 of FCCH message.FCCH message has the variable duration that can change along with the variation of frame, and this depends on the schedule information amount transmitting on the FCCH of this frame.The FCCH message duration is even number OFDM code element, and is provided by the FCCH length field in BCH message.Use the duration of the message (for example BCH and FCCH message) of diversity mode transmission to provide with even number OFDM code element, because diversity mode sends OFDM code element in couples, as described below.

In one embodiment, FCCH can send by four possible speed.FCCH multiplicative model in BCH message for the special speed that in each tdd frame, FCCH PDU uses (Phy Mode) field represents.Each FCCH speed is corresponding to a specific code rate and a specific modulation scheme, and is further associated with specific transmission mode, shown in table 26.

FCCH message can comprise zero, one or more information element (IE).Each information element can be associated with a specific user terminal, and is used for providing for this user terminal the information that represents that FCH/RCH resource is distributed.Table 6 has been listed each field of an exemplary FCCH message format.

Table 6-FCCH message

N_IE information element, each comprising:

N_IE field shows the information element number that the FCCH message of transmission in current tdd frame comprises.The each information element (IE) comprising for FCCH message, IE type field shows the particular type of this IE.Define multiple IE types and be used for as dissimilar transmission Resources allocation, as described below.

MAC IE field has represented the specific user terminal that information element is pointed.Each user terminal is registered to access point in the time that communication session starts, and is access in and is a little assigned to unique MAC ID.This MAC ID is for identifying subscriber terminal during session.

Control field is used for transmitting the channel allocation information of user terminal, and describes in detail below.Filling bit field comprises the filling bit of sufficient amount, and the total length that makes FCCH message is even number OFDM code element.FCCH crc field comprises a crc value, and user terminal can determine that the FCCH message receiving is correctly decoded or by decoded in error with described crc value.Tail bit field comprises the null value that for ending place in FCCH message, convolution coder is reset to known state.Some fields in these fields are described in further detail below.

As shown in table 1, MIMO wlan system is that FCH and RCH support multiple transmission modes.In addition, user terminal can be activity or idle during connecting., defined multiclass IE and be used for distributing FCH/RCH resource into dissimilar transmission.Table 7 is listed one group of exemplary IE type.

Table 7-FCCH IE type

For IE type 0,1 and 4, for FCH and RCH distribute to specific user terminal (with channel, form being distributed) resource.For IE type 2, on FCH and RCH, minimum resource is distributed to user terminal to maintain the latest estimated of link.The example format of each IE type is described below.Conventionally, the speed of FCH and RCH and duration can be distributed to user terminal independently.

A.IE type 0,4-diversity/wave beam control model

IE type 0 and 4 is used for respectively as diversity mode and wave beam control model distribution FCH/RCH resource.For example, for fixing Low rate services (voice), speed keeps fixing for the duration of calling out.For variable rate services, speed can be selected independently to FCH and RCH.FCCH IE represents the position of the FCH and the RCH PDU that distribute to user terminal.Table 8 is listed each field of exemplary IE type 0 and 4 information elements.

Table 8-FCCH IE type 0 and 4

FCH and RCH offset field represent point time migration that is clipped to the beginning of FCH and RCH PDU that starts from current tdd frame, are distributed by information element.FCH and RCH speed field represent respectively the speed of FCH and RCH.

FCH and RCH leader type field represent respectively the size of leader in FCH and RCH PDU.Table 9 is listed the value of FCH and RCH leader type field and relevant leader size.

Table 9-leader type

RCH timing regulates field to comprise two bits of the timing for regulating the ul transmissions from user terminal being identified by MAC id field.This timing regulates the interference that is used for reducing in the frame structure based on TDD (than frame structure as shown in Figure 3A), and wherein down link and ul transmissions are time division duplexs.Table 10 is listed RCH timing and is regulated the value of field and relevant action.

Table 10-RCH timing regulates

RCH power control field comprises two bits from the transmitted power of the ul transmissions of institute's identifying subscriber terminal for adjusting.This power control field is used for reducing the interference in up link.Table 11 is listed the value of RCH power control field and relevant action.

Table 11-RCH determines power control

The channel allocation of institute's identifying subscriber terminal can provide in every way.In one embodiment, user terminal is only assigned to FCH/RCH resource for current tdd frame.In another embodiment, before cancellation, for each tdd frame, FCH/RCH resource is distributed to terminal.Also having in an embodiment, for every n tdd frame, FCH/RCH resource is distributed to user terminal, this is called as " extraction " scheduling of tdd frame.Dissimilar distribution can be shown by the distribution type field in FCCH information element.

B.IE Class1-space multiplexing mode

IE Class1 usage space multiplexer mode is distributed to user terminal FCH/RCH resource.The speed of these user terminals is variable, and can select independently for FCH and RCH.Table 12 is listed each field of an exemplary IE Class1 information element.

Table 12-FCCH IE Class1

For IE Class1, the speed of each space channel can be selected independently on FCH and RCH.The speed decipher of space multiplexing mode normally can be specified the speed (having nearly four space channels for the embodiment shown in table 12) of each space channel because of it.If transmitter is carried out spatial manipulation to send data in eigenmodes, provide speed according to each eigenmodes.If transmitter only from transmitting antenna send data and receiver carry out spatial manipulation so as isolation and recover data (for uncontrolled space multiplexing mode), provide speed according to every antenna.

Information element comprises the speed of the space channel being all activated, and is null value for the channel not being activated.There is the user terminal that is less than four transmit antennas untapped FCH/RCH space channel speed field is made as to zero.Because access point is equipped with four transmit/receive antennas, therefore have more than the user terminal of four transmit antennas and can launch nearly four independent data streams with them.

C.IE type 2-idle pulley

IE type 2 is used for providing control information (as described below) for the user terminal being operated under idle condition.In one embodiment, in the time that user terminal is in idle condition, upgrade constantly the dominant vector that is used for carrying out spatial manipulation by access point and user terminal, transfer of data can be started fast in the time continuing.Table 13 is listed each field of exemplary IE type 2 information elements.

Table 13-FCCH IE type 2

D.IE type 3-RACH confirms fast

IE type 3 is used for providing quick confirmation for attempting by the user terminal of RACH connecting system.In order to acquire the access of system or to send SMS message to access point, user terminal can send RACHPDU in up link.Sent after RACH PDU at user terminal, it monitors that BCH is to determine whether to be provided with RACH acknowledgement bit.If arbitrary user terminal has successfully accessed system and on FCCH at least one user terminal has sent confirmation, this bit is arranged by access point.If be provided with this bit, user terminal is just processed FCCH for the upper confirmation sending of FCCH.If access point wishes not Resources allocation and confirm the RACH PDU that it is correctly decoded from user terminal, IE type 3 information elements are sent out.Table 14 is listed each field of exemplary IE type 3 information elements.

Table 14-FCCH ID type 3

Can on FCCH, define and send the confirmation of single or multiple types.For example, can define the confirmation of confirmation and based on distributing fast.Confirmation can be used for only confirming that RACH PDU has been access in a reception fast, and does not distribute FCH/RCH resource to user terminal.Confirmation based on distributing comprises the distribution for FCH and/or the RCH of current tdd frame.

FCCH can otherwise realize, and also can be sent out in every way.In one embodiment, FCCH is sent out with the single speed transmitting in BCH message.This speed can be based on for example FCCH be sent in current tdd frame all users' lowest signal Noise and Interference is selected than (SNR).According to the channel adjustment of receiver's user terminal in each tdd frame, can use different speed for different tdd frames.

In another embodiment, FCCH for example, realizes with multiple (four) FCCH subchannel.Each FCCH subchannel is sent out with a different speed, and the required SNR different from is relevant, to recover subchannel.FCCH subchannel is sent out to the order of flank speed with minimum speed limit.Each FCCH subchannel may or may in given tdd frame, not be sent out.The one FCCH subchannel (having minimum speed limit) is first sent out, and can be received by all user terminals.This FCCH channel can show in current tdd frame, whether to send each remaining FCCH subchannel.Each user terminal can be processed sent FCCH subchannel and obtain its FCCH information element.Each user terminal can stop the processing of FCCH when any point below occurring: (1) fails the FCCH subchannel of decoding current, (2) in current FCCH channel, receive its FCCH information element, or the FCCH subchannel of (3) all transmissions is all processed.Decode and unsuccessfully just can stop the processing of FCCH as long as user terminal runs into FCCH, because FCCH subchannel is sent out with the speed rising, user terminal can not can be decoded with the follow-up FCCH subchannel of higher rate transmission.

3. direct access communications channels (RACH)-up link

User terminal obtains the access to system and sends SMS message to access point with RACH.The operation of RACH is the Aloha arbitrary access agreement based on time-division slot, and this is described below.

Fig. 5 C has illustrated an embodiment of RACH PDU 450.In this embodiment, RACH PDU comprises leader part 552 and message part 554.If user terminal has many antennas, leader part 552 can be used for sending a controlled benchmark.The pilot tone that controlled benchmark is made up of one group of special modulated symbol, it was subject to spatial manipulation before sending in up link.Spatial manipulation is sent out pilot tone in a specific eigenmodes of mimo channel.Be described in further detail the processing of controlled benchmark below.Leader part 552 has the fixing duration of at least 2 OFDM code elements.Message part 554 transmits a RACH message, and has the variable duration.Therefore the duration of RACH PDU is variable.

In one embodiment, for RACH supports four different speed.The special speed that each RACH message is used is represented by the RACH data rate indicator (DRI) of one 2 bits.In one embodiment, also for RACH supports four different message sizes.The size of each RACH message is represented by the message part field being included in RACH message.Each RACH speed support 1,2,3 or whole 4 message sizes.Table 15 is listed the message size that four RACH speed, their relevant codings and modulation parameter and these RACH speed are supported.

Table 15

RACH message sends from the short message of user terminal and access request.Table 16 is listed each each field size of each field of an exemplary RACH message and four different messages sizes.

Table 16

Message duration field list understands the size of RACH message.MAC PDU type field shows RACH type of message.The MAC ID of the user terminal that MAC id field comprises energy unique identification transmission RACH message.Between starter system access periods, unique MAC ID is not assigned to user terminal.In this situation, can comprise that one registers MAC ID (particular value for example retaining as registration object) in MAC id field.Time slot id field represents the RACH time slot starting, and sends RACH PDU (RACH timing and transmission are described below) on it.Pay(useful) load field comprises the information bit of RACH message.The crc value that crc field comprises RACH message, tail bit field be used for the resetting convolution coder of RACH.Be described in further detail the operation of RACH and BCH and FCCH for system access below.

RACH also can realize with " fast " RACH (F-RACH) and " slowly " RACH (S-RACH).F-RACH and S-RACH can be designed to effectively support user terminal under different operating state.For example, F-RACH can be used by user terminal: (1) is to system registry, (2) compensate their round-trip delay (RTD) by correctly in advance their transmission timing, and (3) realize required SNR for the operation on F-RACH.S-RACH can be used the user terminal of F-RACH to use in no instance.

Can for F-RACH and S-RACH use different designs so that whenever may be just connecting system rapidly, and make to realize the required amount minimum of arbitrary access.For example, F-RACH can use shorter PDU, adopts weak encoding scheme, requires F-RACH PDU time proximity to arrive alignedly access point place, and uses the Aloha random access scheme of time-division slot.S-RACH can use longer PDU, adopts stronger encoding scheme, allows S-RACH PDU to arrive access point in non-alignment ground in time, and uses the not Aloha random access scheme of time-division slot.

For simplicity, below description is assumed to MIMO wlan system and uses single RACH.

4. forward channel (FCH)-down link

Access point uses FCH that customer-specific data is sent to specific user terminal, and paging/broadcast is sent to multiple user terminals.FCH can frame by frame be assigned with.Provide multiple FCH PDU types to adapt to the different purposes of FCH.Table 17 is listed one group of exemplary FCH PDU type.

Table 17-FCH PDU type

FCH PDU type 0 is used on FCH, sending paging/broadcast and user message/grouping, and only comprises message/packet.(data of specific user terminal can be used as a message or a grouping is sent out, and these two terms are in this commutative use.) FCH PDU Class1 is used for sending user grouping and comprises a leader.FCHPDU type 2 only comprises leader and does not comprise any message/packet, and is associated with idle condition FCH traffic.

Fig. 5 D has illustrated an embodiment of the FCH PDU 430a of FCH PDU type 0.In this embodiment, FCH PDU 430a only comprises a message part 534a of paging/broadcast or user grouping.Message/packet can have variable length, and this length is provided by the FCH message length field in FCH PDU.Message-length provides (the following describes) with an integer PHY frame.Specify and described speed and the transmission mode of paging/broadcast below.Speed and the transmission mode of user grouping in relevant FCCH information element, are specified.

Fig. 5 E has illustrated an embodiment of the FCH PDU 430b of FCH PDU Class1.In this embodiment, FCH PDU 430b comprises a leader part 532b and a message/packet part 534b.Leader part 532b is used for sending MIMO pilot tone or controlled benchmark, and has variable length, and variable-length is provided by the FCH leader type field in the FCCH information element of being correlated with.Part 534b is used for sending FCH grouping, and also has variable length (representing with an integer PHY frame), and variable-length is provided by the FCH message length field in FCH PDU.FCH grouping sends by speed and transmission mode that relevant FCCH information element is specified.

Fig. 5 F has illustrated an embodiment of the FCH PDU 430c of FCH PDU type 2.In this embodiment, FCH PDU 430c only comprises leader part 532c, and does not comprise message part.The length of leader part is indicated by FCCH IE.When can be used to make user terminal under idle condition, FCH PDU type 2 can upgrade its channel estimating.

Provide multiple FCH type of messages to adapt to the different purposes of FCH.Table 18 has been listed one group of exemplary FCH type of message.

Table 18-FCH type of message

A beep-page message can be used for the multiple user terminals of paging, and sends by FCH PDU type 0.If be provided with the paging bit in BCH message, first on FCH, send one or more FCH PDU (i.e. " paging PDU ") with pilot tone message.In same frame, can send multiple paging PDU.The transmission of paging PDU is used the minimum speed limit of diversity mode and 0.25bps/Hz, to improve the correct probability receiving of user terminal.

One broadcast can be used to information to send to multiple user terminals, and sends by FCH PDU type 0.If be provided with the broadcast bit in BCH message, after any paging PDU that and then FCH above sends, on FCH, send the one or more FCH PDU (i.e. " broadcast PDU ") with broadcast.The transmission of broadcast PDU is also used the minimum speed limit of diversity mode and 0.25bps/Hz, to improve the correct probability receiving.

One user grouping can be used to send customer-specific data, and can send with FCH PDU Class1 or 2.Send any paging and broadcast PDU on FCH after, Class1 and 2 user PDU are sent out on FCH.Each user PDU can send with diversity, wave beam control or space multiplexing mode.Speed and transmission mode that FCCH information element has specified the each user PDU sending on FCH to use.

The message of the upper transmission of FCH or grouping comprise an integer PHY frame.In one embodiment, as described below, each PHY frame can comprise a crc value, and this value makes can check and retransmit the independent PHY frame in FCH PDU in necessary formula.For asynchronous service, can adopt RLP that the PHY frame in given FCH PDU is carried out segmentation, retransmits and ressembled.In another embodiment, provide a crc value for each message or grouping instead of for each PHY frame.

Fig. 6 has illustrated an embodiment of the structure of FCH grouping 534.FCH grouping comprises an integer PHY frame 610.Each PHY frame 610 comprises pay(useful) load field 622, crc field 624 and tail bit field 626.The one PHY frame of FCH grouping also comprises header fields 620, and it represents type of message and duration.Last PHY frame in FCH grouping also comprises filling bit field 628, and these field 628 endings place in pay(useful) load comprise null filling bit, to fill last PHY frame.In one embodiment, each PHY frame comprises 6 OFDM code elements.The bit number comprising in each PHY frame depends on the speed that this PHY frame uses.

Table 19 is listed each field of the exemplary FCH PDU form of FCH PDU type 0 and 1.

Table 19-FCH PDU form

FCH type of message and FCH message length field are sent out in the header of a PHY frame of FCH PDU.Pay(useful) load, CRC and tail bit field are included in each PHY frame.The pay(useful) load part of each FCH PDU transmits the information bit of paging/broadcast or user's packet dedicated.Filling bit is used for filling as required last PHY frame of FCH PDU.

Also can define the OFDM code element that PHY frame comprises some other quantity (for example 1,2,4,8 etc.).Because for diversity mode OFDM code element being sends in pairs, therefore PHY frame can define by even number OFDM code element, and diversity mode can be used for FCH and RCH.PHY frame size can be selected by the traffic based on expection, nullified property minimum.Particularly, if frame size is excessive, produce ineffectivity by sending low volume data with a large PHY frame.Or if frame size is too small, expense has represented the more most of frame.

5. backward channel (RCH)-up link

User terminal uses RCH that uplink data and pilot tone are sent to access point.RCH can be assigned with according to each tdd frame.Can specify one or more user terminals on RCH, to send in arbitrary given tdd frame.Provide multiple RCH PDU type to adapt to the different working modes on RCH.Table 20 has been listed one group of exemplary RCH PDU type.

Table 20-RCH PDU type

RCH PDU type 0 is used on RCH, sending message/packet, and does not comprise leader.RCHPDU Class1 is used for sending message/packet, and comprises leader.RCH PDU type 2 comprises leader and short message, and is associated with the RCH traffic of idle condition.

Fig. 5 D has illustrated an embodiment of the RCH PDU of RCH PDU type 0.In this embodiment, RCH PDU only comprises the message part 534a of a variable-length RCH grouping, and this grouping is provided with an integer PHY frame by the RCH message length field in RCH PDU.Speed and the transmission mode of RCH grouping are specified in relevant FCCH information element.

Fig. 5 E has illustrated an embodiment of the RCH PDU of RCH PDUY Class1.In this embodiment, RCH PDU comprises leader part 532b and grouping part 534b.Leader part 532b is used for sending a benchmark (for example MIMO pilot tone or controlled benchmark), and has variable length, and described length is provided by the RCH leader type field of being correlated with in FCCH information element.Part 534b is used for sending a RCH grouping, and has variable length, and described variable-length is provided by the RCH message length field in RCH PDU.RCH grouping sends by speed and the transmission mode of specifying in relevant FCCH information element.

Fig. 5 G has illustrated an embodiment of the RCH PDU 350d of RCH PDU type 2.In this embodiment, RCH PDU comprises leader part 532d and message part 535d.Leader part 532d is used for transmission-benchmark, and length is 1,4 or 8 OFDM code element.Part 536d is used for sending a short RCH message, and has the regular length of an OFDM code element.Short RCH message sends (for example speed 1/2 or speed 1/4 and BPSK modulation) by specific speed and transmission mode.

The grouping (for PDU type 0 and 1) of the upper transmission of RCH comprises an integer PHY frame.Fig. 6 illustrates that the structure of RCH grouping is (for PDU type 0 and 1, so same for FCH grouping.RCH grouping comprises an integer PHY frame 610.Each PHY frame comprises pay(useful) load field 622, optional crc field 624 and tail bit field 626.A PHY frame in RCH grouping also comprises header part 620, and last the PHY frame in grouping also comprises filling bit field 628.

Table 21 is listed each field of the exemplary RCH PDU form of RCH PDU type 0 and 1.

Table 21-RCH PDU form (PDU type 0 and 1)

RCH type of message, RCH message-length and FCH rate indicator field are sent out in the header of a PHY frame of RCH PDU.FCH rate indicator field is used for a FCH rate information (maximum rate that for example each space channel is supported) and is sent to access point.

Table 22 has been listed each field of the exemplary RCH PDU form of RCH PDU type 2.

The RCH message of table 22-RCH PDU type 2

User terminal is asked the additional capacity in up link by RCH request field.This short RCH message does not comprise CRC, and is sent out in single OFDM code element.

6. dedicated channel activity

Transfer of data on RCH and RCH can occur independently.According to using for RCH and RCH the transmission mode of selecting, one or more space channels (for wave beam control and diversity mode) can be movable, and for the transfer of data of each dedicated transmission channel.Each space channel can be associated with a specific speed.

As FCH only or when only whole four speed of RCH are set as zero, user terminal is idle on this link.Non-occupied terminal still can send an idle PDU on RCH.Whole four speed at FCH and RCH are all set as at 1 o'clock, and access point and user terminal are all closed and do not sent.The user terminal that is less than four transmit antennas is made as zero the speed field not using.User terminal more than four transmit antennas sends data with being no more than four space channels.The speed that table 23 is illustrated on whole four space channels of one of FCH or RCH (or both) is set as transmission rate and the channel activity of at 1 o'clock.

Table 23

May there is all idle (not sending data) but still send the situation of leader of RCH and FCH.This is called idle condition.As shown in table 13, in FCCH IE type 2 information elements, provide the control field for supporting the user terminal under idle condition.

7. other design

For simplicity, for exemplary design, specific PDU type, PDU structure, message format etc. have been described.Also can define and use less, additional and/or different type, structure and forms, this within the scope of the invention.

III.OFDM sub band structure

In the foregoing description, for whole transmission channels use identical OFDM sub band structure.By using different OFDM sub band structure can realize improved efficiency for different transmission channels.For example, can use 64 sub band structure for some transmission channels, can use for some other transmission channels the structure of 256 subbands, etc.In addition can be that a given transmission channel uses multiple OFDM sub band structure.

For given system bandwidth W, the duration of OFDM code element is depended on sub-band sum.If sub-band sum is N, each duration through conversion code element (there is no Cyclic Prefix) is N/W microsecond (if the unit of W is WHz).Add a Cyclic Prefix to each code element through conversion and form corresponding OFDM code element.The length of Cyclic Prefix is determined by the desired delay spread of system.Cyclic Prefix represents expense, and expense is the expense that each OFDM code element needs for contrary frequency selective channel.If code element is very short, this expense represents the OFDM code element of larger percentage, if code element is very long, this expense just represents the OFDM code element of less percentage.

Because different transmission channels can be associated with dissimilar traffic data, therefore can select a suitable OFDM sub band structure for each transmission channel so that with the traffic data type matching of expection.If expection has mass data to send, can define larger sub band structure for this transmission channel on given transmission channel.In this situation, Cyclic Prefix can represent the OFDM code element of less percentage and realize larger efficiency.On the contrary, if expection will send low volume data on a given transmission channel, can define less sub band structure for this transmission channel.In this situation, even if Cyclic Prefix has represented the larger percentage of OFDM code element, by reduce the quantity of excessive capacity by less OFDM code element size, still can realize higher efficiency.Therefore, OFDM code element can be regarded as one " boxcar (boxcar) ", and the data volume that can will send according to expection is " boxcar " that each transmission channel is selected just size.

For example, for the above embodiments, the data on FCH and RCH are sent out in PHY frame, and each PHY frame is all made up of 6 OFDM code elements.In this situation, can define another OFDM structure for FCH and RCH.For example, can be the structure that FCH and RCH define 256 subbands." greatly " OFDM code element of 256 sub band structure can be approximate four times of 64 sub band structure " little " OFDM code element on the duration, but can be also four times in data transmission capacity.But, only need a Cyclic Prefix for a large OFDM code element, and need four Cyclic Prefix for four little OFDM code elements of equivalence.Like this, by using 256 larger sub band structure can reduce by 75% cyclic redundancy expense number.

This concept can be expanded, thereby can use different OFDM sub band structure for same transmission channel.For example, RCH supports different PDU types, each type and a specific Size dependence connection.In this situation, can be that the RCH PDU type of large-size is used larger sub band structure, and can be the less sub band structure of RCHPDU type use of reduced size.Also can be the combination that given PDU uses different sub-band structure.For example, if a long OFDM code element is equivalent to four short (OFDM) code elements, can use N _largeindividual large OFDM code element and N _smallindividual little OFDM code element sends PDU, wherein N _large>=0 and 3>=N _small>=0.

Different OFDM sub band structure is associated with the OFDM code element of different length.Like this, different transmission channel (and/and being same transmission channel) uses different OFDM sub band structure if, the FCH of FCH and RCHPDU and RCH skew meeting need to be specified by correct temporal resolution, and this temporal resolution is less than an OFDM code-element period.Particularly, the incremental time of FCH and RCH PDU can provide with an integer circulating prefix-length, instead of OFDM code-element period.

IV. speed and transmission mode

Above-mentioned transmission channel is used for as various services and function transmission Various types of data.Each transmission channel can be designed to support one or more speed and one or more transmission mode.

1. transmission mode

For transmission channel is supported multiple transmission mode.As described below, each transmission mode is associated with the particular space processing at transmitter and receiver place.Table 24 is listed the transmission mode that each transmission channel is supported.

Table 24

For diversity mode, for implementation space, frequency and/or time diversity, each data symbols sends redundantly in many transmit antennas, multiple subband, multiple code-element period or their combination.For wave beam control model, single space channel is for transfer of data (being generally best space channel), each data symbols with transmitting antenna can with full transmitted power on single space channel, be sent out.For space multiplexing mode, multiple space channels are for transfer of data, and each data symbols is sent out on a space channel, and wherein a space channel is corresponding to an eigenmodes, a transmitting antenna etc.Wave beam control model can be regarded as the special circumstances of space multiplexing mode, wherein only carries out transfer of data with a space channel.

Diversity mode can be used for the Common transport channel (BCH and FCCH) of the down link from access point to user terminal.Diversity mode also can be used for dedicated transmission channel (FCH and RCH).The use of diversity mode on FCH and RCH can be consulted in the time of call setup.Diversity mode uses a pair of antenna in one " spatial model " the upper data that send for each subband.

Wave beam control model can be adopted by the user terminal with many transmit antennas on RACH.User terminal can be estimated mimo channel based on the upper MIMO pilot tone sending of BCH.Then this channel estimating is used on RACH as system access is carried out wave beam control.Wave beam control model also can be used for dedicated transmission channel (FCH and RCH).By utilizing the gain of transmitter place antenna array, wave beam control model perhaps can be at receiver place than diversity mode realize higher signal to Noise and Interference than (SNR).In addition,, because controlled benchmark only comprises the code element of single " controlled " antenna, therefore the leader of PDU part can reduce.Diversity mode also can be used for RACH.

In the time that channel condition is supported, space multiplexing mode can be used for FCH and RCH realizes higher throughput.Space multiplexing mode and wave beam control model are that benchmark drives, and to correct operation requirements closed-loop control.Like this, user terminal is all assigned to resource with support space multiplexer mode on FCH and RCH.On FCH and RCH, can support nearly four space channels (being subject to access point place antenna amount limits).

2. coding and modulation

For transmission channel is supported multiple different speed.Each speed is associated with a specific code rate and a specific modulation scheme, and both are in conjunction with producing a specific frequency spectrum efficiency (or data rate) afterwards.Table 25 is listed each speed that system is supported.

Table 25

Each Common transport channel is supported one or more speed and transmission mode (or may be multiple, such as the situation of RACH).BCH uses diversity mode to be sent out with fixed rate.Use diversity mode, FCCH can be sent out with one of four possible speed, such as the FCCH multiplicative model field in BCH message is represented.In one embodiment, RACH can be sent out with one of four possible speed, as indicated in the RACH DRI embedding in the leader of RACH PDU, and each RACH message is one of four possible sizes.In another embodiment, RACH is sent out with single speed.Table 26 is listed coding, modulation and transformation parameter and the message size that each Common transport channel is supported.

The parameter of table 26-Common transport channel

The size of FCCH message is variable, and provides with even number OFDM code element.

Whole speed of listing in FCH and RCH support matrix 25.Table 27 is listed coding, modulation and transformation parameter and the message size that FCH and RCH support.

The parameter of table 27-FCH and RCH

Note A: repeat on two subbands in each speed 1/2, to obtain efficient coding speed 1/4.The redundant bit that parity bits presentation code is introduced, and for the error correction of receiver.

PHY frame size in table 27 represents the number of coded-bit, modulated symbol and the OFDM code element of each PHY frame.If transfer of data has been used 48 data subbands, each OFDM code element comprises 48 modulated symbols.For diversity and wave beam control model, send a code element stream, and the single speed that adopts corresponding to this code element stream of PHY frame size.For space multiplexing mode, multiple code element stream can be sent out on multiple space channels, and total PHY frame size can be determined by the PHY frame size sum of independent space channel.The speed that the PHY frame size of each space channel is adopted by this space channel is determined.

For example, suppose mimo channel can be supported in 0.5,1.5,4.5 and the spectrum efficiency of 5.5bps/Hz under four spatial sub-channels of working.So shown in table 28 be four speed that four space channels are selected.

Table 28-instance space multiplexing transmission

So total PHY frame size is 144+432+1296+1584 information bit or 288+576+1728+2304 coded-bit.Even if each of four space channels is supported the pay(useful) load bit of varying number, for example, Zong PHY frame also can be sent out (24 microseconds are supposed 4 microseconds/OFDM code element) in 6 OFDM code elements.

V. physical layer process

Fig. 7 illustrates the block diagram of access point 110x in MIMO wlan system and two user terminal 120x and 120y mono-embodiment.

On down link, at access point 110x place, send (TX) data processor 710 and receive the traffic data (being information bit) from data source 708 and carry out self-controller 730 and signaling and the out of Memory of possible scheduler 734.This Various types of data can be sent out on different transmission channels.Send data processor 710 to data carry out " framing " (if desired), to framing/separate the data of frame upset, to encoding through the data that upset, to encoded data interweave (i.e. rearrangement) and the data-mapping through interweaving to modulated symbol.For simplicity, " data symbols " refers to the modulated symbol of traffic data, and " pilot frequency code element " refers to the modulated symbol of pilot tone.Upset is data bit randomization.Coding has improved the reliability of transfer of data.Interweave and provide time, frequency and/or space diversity for the bit of having encoded.Upset, encode and the control signal that can provide based on controller 730 be provided and carry out, being described in further detail below.Send data processor 710 and provide a modulation, symbol streams for each space channel that transfer of data is used.

Send spatial processor 720 and receive one or more modulation, symbol streams from sending data processor 710, and modulated symbol is carried out to spatial manipulation to four transmitter code flow filaments are provided, have a stream for every transmit antennas.Be described in further detail spatial manipulation below.

Each modulator (MOD) 722 receives and processes a corresponding transmitter code flow filament to a corresponding OFDM code element stream is provided.Each OFDM code element stream is further processed, to a corresponding down link modulated signal is provided.Then send respectively four down link modulated signals of automodulation device 722a to 722d from four antenna 724a to 724d.

At each user terminal 120 places, one or more antenna 752 receives sent down link modulated signal, and every reception antenna all provides one to receive signal to corresponding demodulator (DEMOD) 754.Each demodulator 754 is carried out the contrary processing of processing of carrying out with modulator 722 places, and receiving symbol is provided.Then, receiving (RX) spatial processor 720 receiving symbol from all demodulators 754 is carried out to spatial manipulation so that the code element through recovering to be provided, is the estimation of the modulated symbol that sends of access point through the code element of recovering.

Receiving data processor 770 receives the code element through recovering and its multichannel is decomposed in their corresponding transmission channels.The code element through recovering of each transmission channel can be conciliate and upset through symbol de-maps, deinterleaving, decoding, to provide the data through decoding for this transmission channel.Each transmission channel can comprise grouped data, message, signaling through recovering etc. through decoded data, the latter is provided for data sink 722 and preserves, and/or is provided for controller 780 and is further processed.

The access point 110 of down link and the processing of terminal 120 are described in further detail below.The processing of up link can be identical or different with the processing of down link.

For down link, at each active user terminals 120 places, receive the further estimating down-ward link of spatial processor 760 to obtain channel condition information (CSI).CSI can comprise SNR that channel response is estimated, received etc.Receiving data processor 770 can also provide the state of each packet/frame receiving on down link.Controller 780 receiving channel state informations and packet/frame state, and determine the feedback information that will be sent back to access point.Feedback information is processed by sending data processor 790 and sending spatial processor 792 (if existence), is regulated, and be sent back to access point via one or more antenna 752 by one or more modulators 754.

At access point 110 places, the uplink signal sending by antenna 724 receive, by demodulator 722 demodulation, and process in the contrary mode of mode of carrying out with user terminal place by receiving spatial processor 740 and receiving data processor 742.Then offering controller 730 and scheduler 734 through the feedback information recovering.

Scheduler 734 use feedback informations are carried out several functions, such as (1) selects one group of user terminal for the transfer of data in down link and up link, (2) be each selected user terminal selecting transmission rate and transmission mode, and (3) the FCH/RCH resource that can use to selected terminal distribution.Scheduler 734 and/or controller 730 further use the information (for example dominant vector) obtaining from ul transmissions to process downlink transmission, are described in further detail as follows.

Support multiple transmission mode for the transfer of data in down link and up link.Be described in further detail each processing of these transmission modes below.

1 diversity mode-transmission processing

Fig. 8 A illustrates the block diagram that can carry out for diversity mode transmitter unit 800 1 embodiment of transmission processing.Transmitter 800 can be used for the transmitter part of access point and user terminal.

In transmission data processor 710a, framing unit 808 carries out framing to the data of each grouping that will send on FCH or RCH.Framing is without carrying out for other transmission channel.Framing can be carried out as shown in Figure 6, to generate one or more PHY frames for each user grouping.Then, the data of framing/solution frame that disarrangement device 810 is each transmission channel upset, to make data randomization.

Encoder 812 receives the data through upsetting and according to selected encoding scheme, described data is encoded, to encoded bit is provided.Then, repetition/brachymemma unit 814 repeat or some coded-bits of brachymemma (delete) to obtain the code rate of the expectation of expecting.In one embodiment, encoder 812 is binary convolutional encoder that speed is 1/2, limited length is 7.By each coded-bit is repeated once can obtain code rate 1/4.Can obtain by deleting some coded-bits from encoder 812 code rate that is greater than 1/2.The particular design of framing unit 808, disarrangement device 810, encoder 812 and repetition/brachymemma unit 814 is described below.

Then, interleaver 818 based on selected interleaving scheme to interweaving from the coded-bit of unit 814 (i.e. rearrangement).In one embodiment, every group of 48 continuous programming code bits that send on a given space channel reportedly send subband (or referred to as data subband) upper expansion in 48 numbers, to frequency diversity is provided.Be described in further detail interleaving process below.

Symbol mapped unit 820 then shines upon data through interweaving so that modulated symbol to be provided according to a specific modulation scheme.Shown in table 26, according to selected speed, diversity mode can use BPSK, 4QAM or 16QAM.In diversity mode, for all data subbands use same modulation scheme.Symbol mapped can realize by following: each group of (1) tissue B bit to form B bit value, wherein B >=1, and (2) are mapped to a bit in a signal group of stars corresponding with selected modulation scheme each B bit value.Each mapped signaling point is a complex values, and corresponding to a modulated symbol.Symbol mapped unit 820 provides a modulation, symbol streams to sending diversity processor 720a.

In one embodiment, diversity mode is that two diversity that send are used space time transmit diversity (STTD) according to each subband.STTD supports in independently code element stream is on two transmit antennas to transmit, and maintains the orthogonality at receiver place simultaneously.

STTD scheme operates as follows.Suppose and will on a given subband, send two modulated symbols, be labeled as s ₁and s ₂.Transmitter generates two vectors: x ₁=[s ₁s ₂] ^twith ${\underset{\‾}{x}}_2={\left[\begin{array}{cc}{s}_2^{*}& -s_1^{*}\end{array}\right]}^T$ , wherein " * " represents complex conjugate, " T " represents transposition.Each vector is included in two element (, vectors that will send from two transmit antennas in a code-element period x ₁in the first code-element period, send vector from two antennas x ₂in next code-element period, send from two antennas).

If receiver is equipped with single reception antenna, receiving symbol can be expressed as:

r ₁＝h ₁s ₁+h ₂s ₂+n ₁， (1)

$r_2=h_1{s}_2^{*}-h_2{s}_1^{*}+n_2,$

Wherein r ₁and r ₂that receiver is in two code elements that receive in two continuous code-element periods;

H ₁and h ₂be the path gain from two transmit antennas to reception antenna for the subband in considering, wherein suppose that path gain is constant on this subband, and keep static on the cycle of 2 code elements; And

N ₁and n ₂be respectively with two receiving symbol r ₁and r ₂the noise being associated.

Then receiver can derive two transmit symbol s as follows ₁and s ₂estimation:

${\hat{s}}_1=\frac{h_1^{*}{r}_1-h_2{r}_2^{*}}{{\left|h_1\right|}^2+{\left|h_2\right|}^2}=s_1+\frac{h_1^{*}{n}_1-h_2{n}_2^{*}}{{\left|h_1\right|}^2+{\left|h_2\right|}^2},---\left(2\right)$

${\hat{s}}_2=\frac{h_2^{*}{r}_1+h_1{r}_2^{*}}{{\left|h_1\right|}^2+{\left|h_2\right|}^2}=s_2+\frac{h_2^{*}{n}_1+h_1{n}_2^{*}}{{\left|h_1\right|}^2+{\left|h_2\right|}^2}$

Or transmitter can generate two vectors ${\underset{\‾}{x}}_1={\left[\begin{array}{cc}{s}_1& -s_2^{*}\end{array}\right]}^T$ With ${\underset{\‾}{x}}_2={\left[\begin{array}{cc}{s}_2& s_1^{*}\end{array}\right]}^T,$ And sequentially send this two vectors from two transmit antennas in two code-element periods.So receiving symbol can be expressed as:

$r_1=h_1{s}_1-h_2{s}_2^{*}+n_1,$

$r_2=h_1{s}_2+h_2{s}_1^{*}+n_2.$

Receiver is following estimation of deriving two transmit symbol then:

${\hat{s}}_1=\frac{h_1^{*}{r}_1+h_2{r}_2^{*}}{{\left|h_1\right|}^2+{\left|h_2\right|}^2}=s_1+\frac{h_1^{*}{n}_1+h_2{n}_2}{{\left|h_1\right|}^2+{\left|h_2\right|}^2},$

${\hat{s}}_2=\frac{-h_2{r}_1^{*}+h_1^{*}{r}_2}{{\left|h_1\right|}^2+{\left|h_2\right|}^2}=s_2+\frac{h_1^{*}{n}_2-h_2{n}_1}{{\left|h_1\right|}^2+{\left|h_2\right|}^2}$

Foregoing description can be expanded and be used for having two or many transmit antennas, N _rthe MIMO-OFDM system of root reception antenna and multiple subbands.Two transmit antennas are used for arbitrary given subband.Suppose on a given subband k and will send two modulated symbols, be labeled as s ₁and s (k) ₂(k).Transmitter generates two vectors x ₁=[s ₁(k) s ₂(k)] ^twith ${\underset{\‾}{x}}_2={\left[\begin{array}{cc}{s}_2^{*}\left(k\right)& -s_1^{*}\left(k\right)\end{array}\right]}^T,$ Or two code-element sets of equal value $\left\{x_i\left(k\right)\right\}=\left\{\begin{array}{cc}{s}_1\left(k\right)& s_2^{*}\left(k\right)\end{array}\right\}$ With $\left\{x_j\left(k\right)\right\}=\left\{\begin{array}{cc}{s}_2\left(k\right)& -s_1^{*}\left(k\right)\end{array}\right\}.$ It (is code-element set { x that each code-element set is included in upper two elements that send from corresponding transmitting antenna order in two code-element periods of subband k _i(k) } on subband k, in two code-element periods, send code-element set { x from antenna i _j(k) } on subband k, in 2 same code-element periods, send from antenna j).

In two code-element periods, the vector of the receiving symbol at reception antenna place can be expressed as:

r ₁(k)＝ h _i(k)s ₁(k)+ h _j(k)s ₂(k)+ n ₁(k)，

${\underset{\‾}{r}}_2\left(k\right)={\underset{\‾}{h}}_i\left(k\right)s_2^{*}\left(k\right)-{\underset{\‾}{h}}_j\left(k\right)s_1^{*}\left(k\right)+{\underset{\‾}{n}}_2\left(k\right),$

Wherein r ₁(k) and r ₂(k) be the symbol vector receiving at receiver place in two continuous code-element periods on subband k, each vector comprises N _rthe N of root reception antenna _rindividual receiving symbol;

h _i(k) and h _j(k) be from two transmit antennas i and j to N for subband k _rthe vector of the path gain of root reception antenna, each vector comprises from relevant transmitting antenna to N _rthe channel gain of each root of root reception antenna, wherein supposes that path gain is constant and keep static on 2 code-element periods on this subband; And

n ₁(k) and n ₂(k) be to receive vector with two respectively r ₁(k) and r ₂(k) noise vector being associated.

Then, receiver can be derived two transmit symbol s as follows ₁and s (k) ₂(k) estimation:

${\hat{s}}_1\left(k\right)=\frac{{\underset{\‾}{\overset{^}{h}}}_i^H\left(k\right){\underset{\‾}{r}}_1\left(k\right)-{\underset{\‾}{r}}_2^H\left(k\right){\underset{\‾}{\overset{^}{h}}}_j\left(k\right)}{{\left|\right|{\underset{\‾}{\overset{^}{h}}}_i\left(k\right)\left|\right|}^2+{\left|\right|{\underset{\‾}{\overset{^}{h}}}_j\left(k\right)\left|\right|}^2}=s_1\left(k\right)+\frac{{\underset{\‾}{\overset{^}{h}}}_i^H\left(k\right){\underset{\‾}{n}}_1\left(k\right)-{\underset{\‾}{n}}_2^H\left(k\right){\underset{\‾}{\overset{^}{h}}}_j\left(k\right)}{{\left|\right|{\underset{\‾}{\overset{^}{h}}}_i\left(k\right)\left|\right|}^2+{\left|\right|{\underset{\‾}{\overset{^}{h}}}_j\left(k\right)\left|\right|}^2},$

${\hat{s}}_2\left(k\right)=\frac{{\underset{\‾}{\overset{^}{h}}}_j^H\left(k\right){\underset{\‾}{r}}_1\left(k\right)-{\underset{\‾}{r}}_2^H\left(k\right){\underset{\‾}{\overset{^}{h}}}_i\left(k\right)}{{\left|\right|{\underset{\‾}{\overset{^}{h}}}_i\left(k\right)\left|\right|}^2+{\left|\right|{\underset{\‾}{\overset{^}{h}}}_j\left(k\right)\left|\right|}^2}=s_2\left(k\right)+\frac{{\underset{\‾}{\overset{^}{h}}}_j^H\left(k\right){\underset{\‾}{n}}_1\left(k\right)-{\underset{\‾}{n}}_2^H\left(k\right){\underset{\‾}{\overset{^}{h}}}_i\left(k\right)}{{\left|\right|{\underset{\‾}{\overset{^}{h}}}_i\left(k\right)\left|\right|}^2+{\left|\right|{\underset{\‾}{\overset{^}{h}}}_j\left(k\right)\left|\right|}^2}$

Or transmitter can generate two code-element set { x _i(k) }={ s ₁(k) s ₂(k) } and $\left\{x_j\left(k\right)\right\}=\left\{\begin{array}{cc}-s_2^{*}\left(k\right)& s_1^{*}\left(k\right)\end{array}\right\},$ And send this two code-element sets from two transmit antennas i and j.So the vector of receiving symbol can be expressed as:

${\underset{\‾}{r}}_1\left(k\right)={\underset{\‾}{h}}_i\left(k\right)s_1\left(k\right)-{\underset{\‾}{h}}_j\left(k\right)s_2^{*}\left(k\right)+{\underset{\‾}{n}}_1\left(k\right),$

${\underset{\‾}{r}}_2\left(k\right)={\underset{\‾}{h}}_i\left(k\right)s_2\left(k\right)-{\underset{\‾}{h}}_j\left(k\right)s_1^{*}\left(k\right)+{\underset{\‾}{n}}_2\left(k\right).$

Then, receiver can be derived the estimation of two transmit symbol as follows:

${\hat{s}}_1\left(k\right)=\frac{{\underset{\‾}{\overset{^}{h}}}_i^H\left(k\right){\underset{\‾}{r}}_1\left(k\right)+{\underset{\‾}{r}}_2^H\left(k\right){\underset{\‾}{\overset{^}{h}}}_j\left(k\right)}{{\left|\right|{\underset{\‾}{\overset{^}{h}}}_i\left(k\right)\left|\right|}^2+{\left|\right|{\underset{\‾}{\overset{^}{h}}}_j\left(k\right)\left|\right|}^2}=s_1\left(k\right)+\frac{{\underset{\‾}{\overset{^}{h}}}_i^H\left(k\right){\underset{\‾}{n}}_1\left(k\right)+{\underset{\‾}{n}}_2^H\left(k\right){\underset{\‾}{\overset{^}{h}}}_j\left(k\right)}{{\left|\right|{\underset{\‾}{\overset{^}{h}}}_i\left(k\right)\left|\right|}^2+{\left|\right|{\underset{\‾}{\overset{^}{h}}}_j\left(k\right)\left|\right|}^2},$

${\hat{s}}_2\left(k\right)=\frac{{\underset{\‾}{\overset{^}{h}}}_i^H\left(k\right){\underset{\‾}{r}}_2\left(k\right)-{\underset{\‾}{r}}_1^H\left(k\right){\underset{\‾}{\overset{^}{h}}}_j\left(k\right)}{{\left|\right|{\underset{\‾}{\overset{^}{h}}}_i\left(k\right)\left|\right|}^2+{\left|\right|{\underset{\‾}{\overset{^}{h}}}_j\left(k\right)\left|\right|}^2}=s_2\left(k\right)+\frac{{\underset{\‾}{\overset{^}{h}}}_i^H\left(k\right){\underset{\‾}{n}}_2\left(k\right)-{\underset{\‾}{n}}_1^H\left(k\right){\underset{\‾}{\overset{^}{h}}}_j\left(k\right)}{{\left|\right|{\underset{\‾}{\overset{^}{h}}}_i\left(k\right)\left|\right|}^2+{\left|\right|{\underset{\‾}{\overset{^}{h}}}_j\left(k\right)\left|\right|}^2}$

STTD scheme is described in the paper that is entitled as " A Simple Transmit Diversity Technique forWireless Communications " by S.M.Alamouti, this paper publishing is on the IEEE periodical about the selected field of communication, in October, 1998 No. 8 the 16th volume, 1451-1458 page.STTD scheme is also described in the following common U.S. Patent application of transferring the possession of: in the 09/737th of submission on January 5 calendar year 2001, No. 602 applications, are entitled as " Method and System for Increased Bandwidth Efficiency in Multiple Input-Multiple Output Channels "; And in the 10/179th of submission on June 24th, 2002, No. 439 applications, are entitled as " Diversity Transmission Modes for MIMO OFDM Communication Systems ".

STTD scheme sends a modulated symbol in each code-element period in each subband by two transmit antennas.But, the distributed intelligence in each modulated symbol in two continuous OFDM code elements of STTD scheme.Like this, the symbol recovery at receiver place is carried out based on two OFDM code elements that receive continuously.

STTD scheme is used a pair of transmitting antenna for each data subband.Because access point comprises four transmit antennas, therefore can select the half of every antenna for 48 data subbands.Table 29 is listed exemplary subband-antenna assignment scheme of STTD scheme.

Table 29

Shown in table 29, transmitting antenna 1 and 2 is-26 ,-19 ,-13 etc. subband for index, and transmitting antenna 2 and 4 is-25 ,-18 ,-12 etc. subband for index, and transmitting antenna 1 and 3 is-24 ,-17 ,-11 etc. subband for index, and the rest may be inferred.Four transmit antennas has six different antennas pair.Right each of two antennas is for 8 data subbands, 8 data subbands approximate intervals equably on 48 data subbands.Antenna is to making to the distribution of subband as adjacent sub-bands is used different antennas, and this can provide larger frequency and space diversity.For example, antenna 1 and 2 is for subband-26, and antenna 3 and 4 is for subband-25.

Antenna-allocation of subbands in table 29 also makes as each coded-bit of minimum speed limit 1/4 uses whole four transmit antennas, and this makes antenna diversity maximum.For speed 1/4, each coded-bit is repeated and sends (also referred to as Shuangzi band repeated encoding) on two subbands.Each coded-bit two subbands used are mapped to different antennas pair, make to send this coded-bit with four whole antennas.For example, the bit index 0 and 1 in table 29 is corresponding to the same coded-bit under diversity mode, and the bit that wherein index is 0 sends from antenna 1 and 2 on subband-26, and the bit that index is 1 sends from antenna 3 and 4 on subband 1.For another example, the bit index 2 and 3 in table 29 is corresponding to same coded-bit, and the bit that wherein index is 2 sends from antenna 1 and 3 on subband-17, and the bit that index is 3 sends from antenna 2 and 4 on subband 10.

System can support other to send diversity scheme, and this within the scope of the invention.For example, system can support a space-frequency to send diversity (SFTD), and it can be according to each subband to coming implementation space and frequency diversity.One exemplary SFTD scheme operates as follows.Suppose and generate two modulated symbol s (k) and s (k+1), and they are mapped to two adjacent sub-bands of OFDM code element.For SFTD, launching opportunity is sent code element s (k) and s (k+1) from two antennas on subband k, and can on subband k+1, send code element s from two identical antennas ^*(k+1) and-s ^*(k).Because supposition channel response keeps constant for two right transmissions of code element, therefore modulated symbol is to having used adjacent subband.Receiver place is identical with the processing of STTD scheme for recovering the processing of modulated symbol, except processing the receiving symbol of two subbands instead of the receiving symbol of two OFDM code-element periods.

Fig. 8 B illustrates the block diagram of an embodiment of the transmission diversity processor 720a of the STTD scheme that can realize under diversity mode.

In transmission diversity processor 720a, demultiplexer 832 receives modulation, symbol streams s (n) from sending data processor 710a, and its multichannel is resolved into 48 subflows for 48 data subbands, is labeled as s ₁(n) to s ₁(n).Each modulated symbol subflow comprises a modulated symbol for a code-element period, corresponding to chip rate (T _oFDM) ^-1, wherein T _oFDMit is the duration of an OFDM code element.Each modulation, symbol streams is provided for corresponding transmission subband diversity processor 840.

In each transmission subband diversity processor 840, demultiplexer 842 resolves into two sequence of symhols the modulated symbol multichannel of this subband, and the chip rate of each sequence is (2T _oFDM) ^-1.Space Time Coding device 850 receives these two modulated symbol sequences, and for each 2 code-element periods, uses two code element s in these two sequences ₁and s ₂be that two transmit antennas form two code-element sets $\left\{x_i\right\}=\left\{\begin{array}{cc}{s}_1& s_2^{*}\end{array}\right\}$ With $\left\{x_j\right\}=\left\{\begin{array}{cc}{s}_2& -s_1^{*}\end{array}\right\}.$ Each code-element set comprises two code elements, and each code element is from one of two sequences.By first code element s is provided ₁next provides code element s ₂ ^*and generated code metaset { x _i, wherein obtain s by switch 856a ₁, by getting s with unit 852a ₂conjugation and code-element period of the symbol delay of conjugation is obtained to s with delay cell 854a ₂ ^*.Shown in table 29, two code-element set { x _iand { x _jwill send from the two antenna i and the j that distribute to subband.Space Time Coding device 850 for the first transmit antennas i the first code-element set $\left\{x_i\right\}=\left\{\begin{array}{cc}{s}_1& s_2^{*}\end{array}\right\}$ Offer buffer/multiplexer 870, for the second transmit antennas j second code metaset $\left\{x_j\right\}=\left\{\begin{array}{cc}{s}_2& -s_1^{*}\end{array}\right\}$ Offer another buffer/multiplexer 870.Controlled encoder 850 is called as STTD code element for two code elements that each code-element period provides.

Buffer/multiplexer 870a is used for the STTD code element from all diversity processors 840 to cushion with multiplexed to 870d.According to determining of table 29, each buffer/multiplexer 870 receives pilot frequency code element and STTD code element from suitable transmission subband diversity processor 840.For example, buffer/multiplexer 870a receives subband-26,-24,-22, the modulated symbol of-19 etc. (being mapped to all subbands of antenna 1), buffer/multiplexer 870b receives subband-26,-23,-20, the modulated symbol of-19 etc. (being mapped to all subbands of antenna 2), buffer/multiplexer 870c receives subband-25,-24,-20, the modulated symbol of-18 etc. (being mapped to all subbands of antenna 3), buffer/multiplexer 870d receives subband-25,-23,-22, the modulated symbol of-18 etc. (being mapped to all subbands of antenna 4).

Then for each code-element period, each buffer/multiplexer 870 is respectively four pilot subbands, 24 data subbands and 36 and does not use multiplexed four pilot tones of subband, 24 STTD code elements and 36 zero, to be the sequence that 64 total subbands form one 64 transmit symbol.Although always have 48 data subbands, for diversity mode, only use 24 subbands for every transmit antennas, therefore, it is 36 instead of 12 that every antenna does not use the substantial amt of subband.Each transmit symbol is the complex values (can be zero for untapped subband) sending on a subband in a code-element period.Each buffer/multiplexer 870 provides a transmitter code flow filament x for a transmit antennas _i(n).Each transmitter code flow filament comprises the modular cascade sequence of 64 transmit symbol, and a code-element period has a sequence.Refer back to Fig. 8 A, send diversity processor 720a four transmitter code flow filament x are provided to four OFDM modulator 722a to 722d ₁(n) to x ₄(n).

Fig. 8 C illustrates the block diagram of OFDM modulator 722x mono-embodiment, and this modulator can be used for each OFDM modulator 722a in Fig. 8 A to 722d.In OFDM modulator 722x, invert fast fourier transformation (IFFT) unit 852 receives a transmitter code flow filament x _i, and use the invert fast fourier transformation of one 64 that the sequence of each 64 transmit symbol is converted to its time-domain representation (call through convert code element) (n).Each code element through conversion comprises corresponding to 64 time-domain samplings of 64 subbands altogether.

For each code element through conversion, Cyclic Prefix maker 854 repeat a part through conversion code element to form corresponding OFDM code element.As mentioned above, can use one of two different circulating prefix-lengths.The Cyclic Prefix of BCH is fixed, and is 800nsec.The Cyclic Prefix of all other transmission channels is all optional (or 400nsec or 800nsec), and is represented by the Cyclic Prefix duration field of BCH message.Be that 20MHz, sampling period are the system of 50nsec and 64 fields for bandwidth, each duration through conversion code element is 3.2 milliseconds (i.e. 64 × 50nsec), duration of each OFDM code element or be 3.6 milliseconds or be 4.0 milliseconds, what this depended on that OFDM code element uses is 400nsec or the Cyclic Prefix of 800nsec.

Fig. 8 D has illustrated an OFDM code element.OFDM code element is made up of two parts: the duration be 400 or the Cyclic Prefix (8 or 16 samplings) of 800nsec and duration be 3.2 microseconds through conversion code element (64 samplings).Cyclic Prefix is the copy (being circulation continuous) through last 8 or 16 samplings of conversion code element, and is inserted in before conversion code element.Cyclic Prefix quebaoOFDM1 code element is existing multidiameter expansion time can keep its orthogonality, thereby improved the performance of the harmful path effects of antagonism, and described ill-effect is such as the multipath being caused by frequency selective fading and channel spread.

Cyclic Prefix maker 854 provides an OFDM code element stream to transmitter (TMTR) 856.Transmitter 856 is converted to one or more analog signals OFDM code element stream, and to analog signal amplification further, filtering and up-conversion, is convenient to send from relevant antenna to generate a modulated signal.

The baseband waveform of OFDM code element can be expressed as:

$x_n\left(t\right)=\underset{k=-N_{\mathrm{ST}}/2,k\≠0}{\overset{N_{\mathrm{ST}}/2}{\mathrm{\Σ}}}{c}_n\left(k\right){\mathrm{\Ψ}}_n(k,t),---\left(3\right)$

Wherein n represents code-element period (being OFDM symbol index);

K represents subband index;

N _sTit is the number of pilot tone and data subband;

C _n(k) be illustrated in the code element sending on the subband k of code-element period n; And

Wherein T _cPit is the Cyclic Prefix duration;

T _sit is the OFDM code element duration; And

Δ f is the bandwidth of each subband.

2. space multiplexing mode-transmission processing

Fig. 9 A illustrates the block diagram that can carry out for space multiplexing mode the transmitter unit 900 of transmission processing.Transmitter unit 90 is another embodiment of the transmitter part of access point and user terminal.For space multiplexing mode, same supposition has four transmit antennas and four reception antennas to use, and data can nearly send on four space channels.For each space channel uses different speed according to its transmission capacity.The specific code rate of each rate domain one and modulation scheme are associated, as shown in Table 25.In the following description, suppose and select N _eindividual space channel is for transfer of data, wherein N _e≤ N _s≤ min{N _t, N _r.

Sending in data processor 710b, framing unit 808 carries out framing to the data of each FCH/RCH grouping to generate one or more PHY frames for this grouping.Each PHY frame is included in can be at whole N in 6 OFDM code elements _ethe data bit number sending in individual space channel.Disarrangement device 810 is upset the data of each transmission channel.Encoder 812 receives the data through upsetting and according to selected encoding scheme, it is encoded, to coded-bit is provided.In one embodiment, using a common encoding scheme is all N _ethe data of individual space channel are encoded, and carry out brachymemma coded-bit, thereby obtain different code rates for different space channels by the brachymemma pattern with different.Therefore, brachymemma unit 814 brachymemma coded-bits are to obtain the code rate of expecting for each space channel.Be described in further detail the brachymemma of space multiplexing mode below.

Demultiplexer 816 is from brachymemma unit 814 received code bits, and multichannel decomposes described coded-bit so that the N for selecting _eindividual space channel provides N _eindividual coded bit stream.Each coded bit stream is provided for a corresponding interleaver 818, the coded-bit that interleaver interweaves in this stream on 48 data subbands.Be described in further detail the coding of space multiplexing mode below and interweave.Be provided for corresponding symbol mapped unit 820 from the data through interweaving of each interleaver 818.

In space multiplexing mode, according to being the reception SNR that four space channels are realized, can use nearly four different speed for these space channels.Each speed is associated with a specific modulation scheme, as shown in Table 25.Each symbol mapped unit 820 shines upon the data through interweaving according to the certain modulation schemes of selecting for correlation space channel, to modulated symbol is provided.In whole four space channels of selecting, symbol mapped unit 820a provides four modulation, symbol streams of four space channels to 820d to sending spatial processor 720b.

Sending spatial processor 720b is that space multiplexing mode is carried out spatial manipulation.For simplicity, below describe and be assumed to transfer of data utilization rate four transmit antennas, four reception antennas and 48 data subbands.Data subband index provides by gathering K, wherein for above-mentioned OFDM sub band structure, and K=± 1 ..., and 6,8..., 20,22 ... 26}.

The model of MIMO-OFDM system can be expressed as:

r(k)＝ H(k) x(k)+ n(k)， k∈K， (5)

Wherein r(k) be to have " reception " of four vectorial (for the code element receiving by four reception antennas of subband k r(k)=[r ₁(k) r ₂(k) r ₃(k) r ₄(k)] ^t);

x(k) be that the code element sending for the four transmit antennas by subband k has " transmission " of four vectorial ( x(k)=[x ₁(k) x ₂(k) x ₃(k) x ₄(k)] ^t);

h(k) be (N of subband k _r× N _t) channel response matrix; And

n(k) be the vector of the Additive White Gaussian Noise (AWGN) of subband k.

Suppose noise vector n(k) component has zero-mean, and covariance matrix is Λ _n=σ ² i, wherein iunit matrix, σ ²it is noise variance.

The channel response matrix of subband k h(k) can be expressed as:

$\underset{\‾}{H}\left(k\right)=\left[\begin{array}{cccc}{h}_{\mathrm{1,3}}\left(k\right)& h_{\mathrm{1,2}}\left(k\right)& h_{\mathrm{1,3}}\left(k\right)& h_{\mathrm{1,4}}\left(k\right)\\ h_{\mathrm{2,1}}\left(k\right)& h_{\mathrm{2,2}}\left(k\right)& h_{\mathrm{2,3}}\left(k\right)& h_{\mathrm{2,4}}\left(k\right)\\ h_{\mathrm{3,1}}\left(k\right)& h_{\mathrm{3,2}}\left(k\right)& h_{\mathrm{3,3}}\left(k\right)& h_{\mathrm{3,4}}\left(k\right)\\ h_{\mathrm{4,1}}\left(k\right)& h_{\mathrm{4,2}}\left(k\right)& h_{\mathrm{4,3}}\left(k\right)& h_{\mathrm{4,4}}\left(k\right)\end{array}\right],k\∈K,---\left(6\right)$

Wherein h _ij(k) be connection item (being complex gain) between transmitting antenna i and the reception antenna j of subband k (for i ∈ 1,2,3,4} and j ∈ 1,2,3,4}).For simplicity, suppose channel response matrix h(k) (for k ∈ K) is known, or can by transmitter and receiver both determine.

The channel response matrix of each subband h(k) can be by " diagonalization ", to be this subband acquisition N _sindividual eigenmodes.This can pass through correlation matrix h(k) carry out eigen value decomposition and realize, r(k)= h ^h(k) h(k), wherein h ^h(k) represent h(k) conjugate transpose.Correlation matrix r(k) eigen value decomposition can be expressed as:

R(k)＝ V(k) D(k) V ^H(k)， k∈K， (7)

Wherein v(k) be (a N _t× N _t) unitary matrix, its row are r(k) eigenvector ( v(k)=[ v ₁(k) v ₂(k) v ₃(k) v ₄(k)], wherein each v _i(k) be the eigenvector of an eigenmodes); And

d(k) be r(k) (the N of eigenvalue _t× N _t) diagonal matrix.

The characteristic of unitary matrix is m ^h m= i.Eigenvector v _i(k) (for i ∈ 1,2,3,4}) also referred to as the transmission space vector of each space channel.

Channel response matrix h(k) also can carry out diagonalization by singular value decomposition, be expressed as follows:

H(k)＝ U(k) ∑(k) V ^H(k)， k∈K， (8)

Wherein v(k) be to classify as h(k) matrix of right eigenvector;

∑(k) be to comprise h(k) diagonal matrix of singular value, they are ddiagonal element (k) ( r(k) eigenvalue) positive square root; And

u(k) be to classify as h(k) matrix of left eigenvector.

Singular value decomposition is described in the book that is entitled as " Linear Algebra and Its Applications " by Gilbert Strang, the Academic publishing house second edition in 1980.As shown in formula (7) and (8), matrix v(k) row are r(k) eigenvector and h(k) right eigenvector.Matrix u(k) row are h(k) h ^h(k) eigenvector and h(k) left eigenvector.

The diagonal matrix of each subband d(k) null value that comprises non-negative real-valued and other position on diagonal. r(k) eigenvalue is marked as { { λ ₁(k), λ ₂(k), λ ₃(k), λ ₄} or { λ (k) ₁(k) }, for i ∈ { 1,2,3,4}.

For 48 data subbands each, it can be channel response matrix h(k) carry out independently eigen value decomposition, (suppose each matrix to determine four eigenmodes for this subband h(k) be all full arrangement).Each diagonal matrix d(k) four eigenvalues can be sorted, and make { λ ₁(k)>=λ ₂(k)>=λ ₃(k)>=λ ₄(k) }, wherein for subband k, λ ₁(k) be dominant eigenvalue, λ ₄(k) be smallest eigen.When each diagonal matrix d(k) when eigenvalue is sorted, correlation matrix v(k) also correspondingly sequence of eigenvector (or row).

It (is that broadband eigenmodes m comprises that eigenmodes in all subbands m) that " broadband " eigenmodes can be defined as the set of the eigenmodes of phase same order in all subbands after sequence." mainly " broadband eigenmodes be after sequence with each matrix in the eigenmodes that is associated of maximum singular value.

Then form vector d ^m, comprise that the m of all 48 data subbands arranges eigenvalue.This vector d ^mcan be expressed as:

d ^m＝[λ _m(-26)...λ _m(-22)...λ _m(22)...λ _m(26)]，m＝{1，2，3，4} (9)

Vector d ¹comprise the eigenvalue of the best or main broadband eigenmodes.For the MIMO-OFDM system (i.e. 4 × 4 systems) that has four transmit antennas and four reception antennas, there are nearly four broadband eigenmodes.

If the noise variance at receiver place is constant and known for transmitter on working band, pass through eigenvalue λ _m(k) divided by noise variance σ ²can determine the reception SNR of each subband of each broadband eigenmodes.For simplicity, suppose that it (is σ that noise variance equals 1 ²=1).

For space multiplexing mode, total transmitted power P that can use for transmitter _totalcan be assigned to broadband eigenmodes based on various power allocation schemes.In a kind of scheme, total transmitted power P _totaldistributed to equably all four broadband eigenmodes, made P _m=P _total/ 4, wherein P _mit is the transmitted power that is assigned to broadband eigenmodes m.In another kind of scheme, use water filling (water-filling) process total transmitted power P _totaldistribute to four broadband eigenmodes.

The injecting process distributes power, makes the broadband eigenmodes with higher-wattage receive the more most of total transmitted power.The amount of transmit power of distributing to a given broadband eigenmodes depends on that it receives SNR, receives the power gain (or eigenvalue) that SNR depends on again whole subbands of this broadband eigenmodes.The injecting process can distribute null value transmitted power to the broadband eigenmodes enough with poor reception SNR.The injecting process is that four broadband eigenmodes receive β={ β ₁, β ₂, β ₃, β ₄, wherein β _mbe the normalization factor of broadband eigenmodes m, and can be expressed as:

${\mathrm{\β}}_m=\frac{1}{\underset{k\∈K}{\mathrm{\Σ}}{{\mathrm{\λ}}_m}^{-1}\left(k\right)},m=\left\{\mathrm{1,2,3,4}\right\}.---\left(10\right)$

As described below, normalization factor β _mafter the reversion of application channel, the transmitted power of distributing to broadband eigenmodes m is remained unchanged.As shown in formula (10), normalization factor β _mcan be based on vector d ^min eigenvalue and hypothesis noise variance to equal 1 (be σ ²=1) derive.

Then, the injecting process is based on set βdetermine total transmitted power that will be assigned to each broadband eigenmodes, make to optimize spectrum efficiency or some other standard.The transmitted power that the injecting process is distributed to broadband eigenmodes m can be expressed as:

P _m＝α _mP _total，m＝{1，2，3，4} (11)

The power division of four broadband eigenmodes can be by α={ α ₁, α ₂, α ₃, α ₄provide, wherein $\underset{m=1}{\overset{4}{\mathrm{\Σ}}}{\mathrm{\α}}_m=1$ And $\underset{m=1}{\overset{4}{\mathrm{\Σ}}}{P}_m=P_{\mathrm{total}}.$ If set αin to have a more than value be non-zero, can select space multiplexing mode.

The process of carrying out water filling is well known in the art, no longer describes here.A bibliography of describing water filling is " the Information Theory and Reliable Communication " that Robert G.Gallager shows, JohnWiley and Sons publishing house, and 1968, it is incorporated into this by reference.

For space multiplexing mode, the speed of each space channel or broadband eigenmodes is selected can be based on: this space channel/broadband eigenmodes is assigned to transmitted power P at it _mthe reception SNR of Shi Shixian.For simplicity, the transfer of data in the eigenmodes of supposition broadband is below described.The reception SNR of each broadband eigenmodes can be expressed as:

${\mathrm{\γ}}_m=\frac{P_m{\mathrm{\β}}_m}{{\mathrm{\σ}}^2},m=\left\{\mathrm{1,2,3,4}\right\}---\left(12\right)$

In one embodiment, the speed of each broadband eigenmodes determines based on a form, and this form comprises speed that system is supported and the SNR scope of each speed.This form can obtain by Computer Simulation, experiment measuring etc.The special speed that each broadband eigenmodes will be used is the speed in this form, has the SNR of the certain limit of the reception SNR that comprises broadband eigenmodes.In another embodiment, the speed of each broadband eigenmodes is based on the selection of getting off: the reception SNR of (1) broadband eigenmodes, (2) for making up the variability of evaluated error, mimo channel and the SNR of other factors skew, and (3) speed of supporting and the form of their required SNR.For this embodiment, calculate first as described above the average received SNR of each broadband eigenmodes, or as on average the calculating of the reception SNR of all subbands of broadband eigenmodes (taking dB as unit).In either case, then calculate an operating SNR, equal to receive SNR and SNR skew sum (both are all taking dB as unit).Then the required SNR of each speed operating SNR being supported with system compares.Then select the flank speed in form for broadband eigenmodes, its required SNR is less than or equal to operating SNR.The speed that sends diversity mode and wave beam control model also can be determined in a similar manner.

For the transmitted power P of each broadband eigenmodes distribution _mcan be distributed in 48 data intersubbands of this broadband eigenmodes, make the reception SNR approximately equal of all subbands.This power is called as channel reversion in the non-homogeneous distribution of intersubband.Distribute to the transmitted power P of each subband _m(k) can be expressed as:

$P_m\left(k\right)=\frac{{\mathrm{\β}}_m{P}_m}{{\mathrm{\λ}}_m\left(k\right)},k\∈K,m=\left\{\mathrm{1,2,3,4}\right\}---\left(13\right)$

Wherein β _min formula (10), provide.

As shown in formula (13), transmitted power P _mbe distributed between data subband, channel power gains by eigenvalue λ channel power inhomogeneous gain based on them _m(k) provide, for k ∈ K.Power distributes and makes all to realize approximately equalised reception SNR at receiver place for all data subbands of each broadband eigenmodes.The reversion of this channel is carried out independently for each of four broadband eigenmodes.Be reversed in by the channel of broadband eigenmodes in the U.S. Patent application of following common transfer and be described in further detail: submit on August 27th, 2002 the 10/229th, No. 209 U.S. Patent applications, are entitled as " Coded MIMO Systems with Selective Channel Inversion AppliedPer Eigenmode ".

Channel reversion can be carried out in various manners.For all channel reversion, if selected a broadband eigenmodes, all data subbands are all for transfer of data.For selective channel reversion, it can be a whole or subset of each broadband eigenmodes choice for use data available subband.Selective channel reversion abandons and receives the bad subband of SNR lower than specific threshold, and only selected subband is carried out to channel reversion.The selective channel reversion of each broadband eigenmodes is also at the 10/229th of common transfer, in No. 209 U.S. Patent applications, describe, this patent was submitted on August 27th, 2002, was entitled as " Coded MIMO Systems with Selective Channel InversionApplied Per Eigenmode ".For simplicity, below describe and be assumed to each broadband eigenmodes execution all channel reversion of selecting.

The gain used of each subband of each broadband eigenmodes can be based on distributing to this subband transmitted power P _m(k) determine.The gain g of each data subband _m(k) can be expressed as:

$g_m\left(k\right)=\sqrt{P_m\left(k\right)},k\∈K,m=\left\{\mathrm{1,2,3,4}\right\}---\left(14\right)$

It can be each subband definition pair of horns gain matrix g(k).This matrix g(k) comprise the gain of four eigenmodes of subband k along diagonal, and can be expressed as: g(k)=diag[g ₁(k), g ₂(k), g ₃(k), g ₄(k)]

For space multiplexing mode, the transmission vector of each data subband x(k) can be expressed as:

x(k)＝ V(k) G(k) s(k)， k∈K， (15)

Wherein

s(k)＝[s ₁(k) s ₂(k) s ₃(k) s ₄(k)] ^T，

x(k)＝[x ₁(k) x ₂(k) x ₃(k) x ₄(k)] ^T

Vector s(k) comprise four modulated symbols that will send, vector in four of a subband k eigenmodes x(k) comprise four transmission code elements will sending from four of a subband k antenna.For simplicity, formula (15) does not comprise the correction factor that the difference of the transmission chain/receive chain that makes up access point and user terminal place is used, and describes in detail below.

Fig. 9 B illustrates the block diagram that can carry out for space multiplexing mode transmission spatial processor 720b mono-embodiment of spatial manipulation.For simplicity, below describe supposition and selected all four broadband eigenmodes.But, also can select and be less than four broadband eigenmodes.

In processor 720b, demultiplexer 932 receives four modulation, symbol streams that will send in four broadband eigenmodes and (is labeled as s ₁(n) to s ₄(n)), 48 subflows of each stream demultiplexer, and four modulation, symbol streams of each data subband are offered to corresponding transmission subband spatial processor 940 for 48 data subbands.Each processor 940 is that a subband is carried out the processing shown in formula (15).

(be labeled as s in 940, four modulated symbol subflows of each transmission subband spatial processor ₁(k) to s ₄(k)) be provided for four multiplier 942a to 942d, multiplier also receives the gain g of four eigenmodes of relevant subbands ₁(k), g ₂(k), g ₃and g (k) ₄(k).Each gain g _m(k) transmitted power P that can be based on distributing to this subband/eigenmodes _m(k) determine, as shown in formula (14).Each its g that gains of multiplier 942 use _m(k) carry out its modulated symbol of convergent-divergent to the modulated symbol through convergent-divergent is provided.Multiplier 942a offers respectively four beam-shaper 950a to 950d to 942d by four modulated symbol subflows through convergent-divergent.

Each beam-shaper 950 is carried out beam forming, in an eigenmodes of a subband, sends a code element subflow.Each beam-shaper 950 receives a code element subflow s of relevant eigenmodes _m(k) and one eigenvector v _m(k).Particularly, beam-shaper 950a receives the eigenvector of the first eigenmodes v ₁(k), beam-shaper 950d receives the eigenvector of the second eigenmodes v ₂(k), the rest may be inferred.Beam forming is carried out with the eigenvector of relevant eigenmodes.

In each beam-shaper 950, be provided for four multiplier 952a to 952d through the modulated symbol of convergent-divergent, multiplier also receives relevant eigenmodes v _m(k) four element v of eigenvector _{m, 1}(k), v _{m, 2}(k), v _{m, 3}and v (k) _{m, 4}(k).Then, each its eigenvector value of multiplier 952 use v _{m, j}(k) " through beam forming " code element is provided through the modulated symbol of convergent-divergent providing.Multiplier 952a offers respectively adder 960a to 960d to 952d four code element subflows through beam forming (they will send from four antennas).

Each adder 960 receives four code elements through beam forming of four eigenmodes of each code-element period, and their are added to provide through preregulated code element for relevant transmitting antenna.Adder 960a respectively offers buffer/multiplexer 970a to 970d four of four transmit antennas through preregulated code element subflow to 960d.

Each buffer/multiplexer 970 is that 48 data subbands are from sending subband spatial processor 940a to 940k reception pilot frequency code element with through preregulated code element.Then, for each code-element period, each buffer/multiplexer 970 is respectively 4 pilot subbands, 48 data subbands and 12 and does not use multiplexed 4 pilot frequency code elements of subband, 48 through preregulated code element and 12 zero, to form one 64 sequences that send code elements for this code-element period.Each buffer/multiplexer 970 provides a transmission code element stream x for a transmit antennas _i(n), wherein send code element stream and comprise 64 modular cascade sequences that send code element.Send code element and can use correction factor convergent-divergent, to make up the poor, as described below of access point and user terminal place transmission chain/receive chain.The follow-up OFDM modulation of each transmission code element stream has been described above.

Paralleled code element stream also can send from four transmit antennas, and does not use the spatial manipulation of uncontrolled space multiplexing mode at access point place.For this pattern, can omit beam-shaper 950 and carry out from channel Umklapp process and beam forming.Flow through further OFDM of each modulated symbol processes, and sends from corresponding transmitting antenna.

Uncontrolled space multiplexing mode can be used for various occasions, such as not carrying out at transmitter support the necessary spatial manipulation of wave beam control based on eigenmode decomposition in the situation that.This may be because transmitter is not yet carried out calibration process, and can not generate enough good estimations of channel, or does not calibrate and eigenmodes processing.For uncontrolled space multiplexing mode, spatial reuse is still used for improving transmittability, but receiver is carried out spatial manipulation to separate independent code element stream.

For uncontrolled space multiplexing mode, receiver is carried out spatial manipulation to recover the code element stream sending.Particularly, user terminal can be realized channel correlation matrix reversion (CCMI) technology, least mean-square error (MMSE) technology, successively interference cancellation receiver treatment technology or some other receiver space treatment technology.These technology are the 09/993rd of common transfer the, in No. 087 U.S. Patent application, describe in detail, this patent was submitted to November 6 calendar year 2001, was entitled as " Multiple-Access Multiple-Input Multiple-Output (MIMO) Communication System ".Uncontrolled space multiplexing mode can be used for down link and ul transmissions.

Multi-User Dimension multiplexer mode supports to arrive on down link the transfer of data of multiple user terminals simultaneously based on " space characteristics " of user terminal.The space characteristics of user terminal is provided by the channel response vector between access point antenna and each user terminal antenna (for each subband).The controlled benchmark that access point can send based on user terminal obtains space characteristics.Access point can be processed the space characteristics of the user terminal of expected data transmission, with: transfer of data when (1) selects one group of user terminal to be used on down link, and (2) are for being sent to each independent data stream derivation dominant vector of selected user terminal.

The dominant vector of Multi-User Dimension multiplexer mode can be derived in every way.Two exemplary schemes are described below.For simplicity, below describe for a subband, suppose that each user terminal is equipped with single antenna.

In the first scheme, access point uses channel reversion to obtain dominant vector.Access point can be selected N _apindividual single antenna user terminal transmitted for time on down link.Access point is that each selected user terminal obtains one 1 × N _apchannel response row vector, and form a N _ap× N _apchannel response matrix h _mu, this matrix has N _apthe N of individual user terminal _apindividual row vector.Then, access point is N _apindividual selected user terminal obtains N _apthe matrix of individual dominant vector h _steer, ${\underset{\‾}{H}}_{\mathrm{steer}}={\underset{\‾}{H}}_{\mathrm{mu}}^{-1}.$ Access point also can send a controlled benchmark to each selected user terminal.Its controlled benchmark of each user terminal processes is estimated channel gain and phase place, and with channel gain and phase estimation be its single antenna demodulation receiving symbol, with obtain through recover code element.

In first scheme, access point is decoded in advance and will be sent to N _apthe N of individual user terminal _apindividual code element stream, makes these code element stream be subject to hardly cross-talk at user terminal place.Access point can be N _apindividual selected user terminal forms channel response matrix h _mu, and right h _mucarry out OR Factorization, make h _mu= f _tri q _mu, wherein t _triwith q _muit is unitary matrix.Access point is then used matrix t _trin in advance decodes _apindividual stream of data symbols, to obtain N _apthe individual code element stream through pre decoding a, and use unitary matrix q _mufurther process through the code element stream of pre decoding and supply to send to N to obtain _apthe N of individual user terminal _apindividual transmission code element stream.Equally, access point also can send a controlled benchmark to each user terminal.Each user terminal uses controlled benchmark to its receiving symbol coherent demodulation to obtain the code element through recovering.

For the up link in Multi-User Dimension multiplexer mode, access point can recover by N with the processing of MMSE receiver, successively interference cancellation or some other receiver treatment technology _apthe N that individual user terminal sends simultaneously _apindividual code element stream.Access point can be estimated the uplink channel responses of each user terminal, and estimates to carry out receiver space processing and carry out scheduling uplink to transmit with channel response.Each single antenna user terminal can send an orthogonal guide frequency in up link.From N _apthe uplink pilot of individual user terminal can be in time and/or is orthogonal in frequency.Time quadrature is realized like this: by making each terminal orthogonal sequence distributing to this user terminal cover its uplink pilot.Frequency orthogonal realizes like this: make each user terminal on a different set of subband, send its uplink pilot.Ul transmissions from user terminal should for example, in access point place time proximity alignment (time unifying in paging prefix).

3. wave beam control model-transmission processing

Figure 10 A illustrates the block diagram that can carry out for wave beam control model the transmitter unit 1000 of transmission processing.Transmitter unit 1000 is embodiment in addition of the transmitter section of access point and user terminal.

Sending in data processor 710c, the data framing of framing unit 808 to each FCH/RCH grouping is to generate one or more PHY frames for this grouping.Disarrangement device 810 is then for the data of each transmission channel upset.Encoder 812 is then encoded through the data of framing according to selected encoding scheme, to coded-bit is provided.Then, brachymemma unit 814 brachymemma coded-bits are to be that transfer of data broadband eigenmodes used obtains the code rate of expecting.Coded-bit from brachymemma unit 818 is interleaved between all data subbands.Then, symbol mapped unit 820 shines upon the data through interweaving to modulated symbol is provided according to selected modulation scheme.Then,, for wave beam control model, send spatial processor 720c modulated symbol is carried out to transmission processing.

Wave beam control model can be used in a space channel or broadband eigenmodes, to send data-described space channel or broadband eigenmodes is generally the space channel being associated with the dominant eigenvalue of all data subbands.If the transmit power assignment of broadband eigenmodes is only being gathered aone of middle generation non-zero, can select wave beam control model.And space multiplexing mode is carried out beam forming based on its eigenvector to the each selected eigenmodes of each subband, wave beam control model is carried out wave beam control based on " standardized " eigenvector, and its principle is to make the eigenmodes of each subband send data in this single eigenmodes.

For main eigenmodes, each eigenvector v ₁(k) four elements of (for k ∈ K) may have different sizes.Thereby the transmission vector of four every antennas may have different sizes, each described send vector comprise a given transmitting antenna all data subbands through preregulated code element.For example, if the transmitted power of each transmitting antenna is restricted the restriction of power amplifier (due to), the gross power that beam forming technique may not exclusively use every antenna to use.

Wave beam control model is only used the eigenvector from main eigenmodes v ₁(k) phase information of (for k ∈ K), and to each eigenvector standardization, make whole four units in eigenvector have equal size.Subband k through standardized eigenvector can be expressed as:

$\underset{\‾}{\overset{~}{v}}\left(k\right)={\left[\begin{array}{cccc}A{e}^{j{\mathrm{\θ}}_1\left(k\right)}& {\mathrm{Ae}}^{j{\mathrm{\θ}}_2\left(k\right)}& {\mathrm{Ae}}^{j{\mathrm{\θ}}_3\left(k\right)}& {\mathrm{Ae}}^{j{\mathrm{\θ}}_4\left(k\right)}\end{array}\right]}^T,---\left(16\right)$

Wherein A is a constant (for example A=1); And

θ _i(k) be the phase place of the subband k of transmitting antenna i, be expressed as:

${\mathrm{\θ}}_i\left(k\right)=\∠v_{1,i}\left(k\right)={\tan }^{-1}\left(\frac{\mathrm{Im}\left\{v_{1,i}\left(k\right)\right\}}{\mathrm{Re}\left\{v_{1,i}\left(k\right)\right\}}\right)---\left(17\right)$

As shown in formula (17), vector in the phase place of each element from eigenvector v ₁(k) respective element obtains (, θ _i(k) from v _{1, i}(k) obtain, wherein v ₁(k)=[v _1,1(k) v _1,2(k) v _1,3(k) v _{isosorbide-5-Nitrae}(k)] ^t).

Also can carry out channel reversion for wave beam control model, make to use a common speed for all data channels.For wave beam control model, distribute to the transmitted power of each data subband can be expressed as:

${\tilde{P}}_1\left(k\right)=\frac{{\widetilde{\mathrm{\β}}}_1{\tilde{P}}_1}{{\widetilde{\mathrm{\λ}}}_1\left(k\right)},k\∈K,---\left(18\right)$

Wherein to keep the constant normalization factor of total transmitted power after the reversion of application channel;

it is the transmitted power of distributing to each root of four antennas; And

it is the power gain for the subband k of the main eigenmodes of wave beam control model.

Normalization factor can be expressed as:

${\widetilde{\mathrm{\β}}}_1=\frac{1}{\underset{k\∈K}{\mathrm{\Σ}}{\widetilde{\mathrm{\λ}}}_1^{-1}\left(k\right)}---\left(19\right)$

Transmitted power can be given P ₁=P _total/ 4 (being the uniform distribution of total transmitted power between four transmit antennas).

Power gain can be expressed as:

${\widetilde{\mathrm{\λ}}}_1\left(k\right)={\underset{\‾}{\overset{~}{v}}}^H\left(k\right){\underset{\‾}{H}}^H\left(k\right)\underset{\‾}{H}\left(k\right)\underset{\‾}{\overset{~}{v}}\left(k\right)---\left(20\right)$

For 48 data subbands, channel reversion causes power division, for k ∈ K.So the gain of each data subband can be given $\tilde{g}\left(k\right)=\sqrt{{\tilde{P}}_1\left(k\right)}.$

For wave beam control model, the transmission vector of each subband x(k) can be expressed as:

$\underset{\‾}{x}\left(k\right)=\underset{\‾}{\overset{~}{v}}\left(k\right)\tilde{g}\left(k\right)s\left(k\right),$ k∈K. (21)

Be for simplicity equally, formula (21) does not comprise the correction factor of the difference of the transmission chain/receive chain for making up access point and user terminal place.

As shown in formula (16), the standardization control vector of each subband four elements may have equal size, but may have different phase places.Therefore, wave beam control is that each subband generates a transmission vector x(k), x(k) four elements have identical size but may have different phase places.

Figure 10 B illustrates the block diagram that can carry out for wave beam control model transmission spatial processor 720c mono-embodiment of spatial manipulation.

In processor 720c, demultiplexer 1032 receives modulation, symbol streams s (n) and its multichannel is resolved into 48 subflows (being labeled as s (1) to s (k)) of 48 data subbands.Each code element subflow is provided for corresponding transmission subband wave beam control processor 1040.Each processor 1040 is that a subband is carried out the processing shown in formula (14).

In each transmission subband wave beam control processor 1040, modulated symbol subflow is provided for multiplier 1042, and multiplier 1042 is also relevant subband receiving gain .Then, multiplier 1042 use gains convergent-divergent modulated symbol is to obtain the modulated symbol through convergent-divergent, and the latter is then provided for wave beam control unit 1050.

Wave beam control unit 1050 also receives the standardization eigenvector of relevant subbands .In wave beam control unit 1050, be provided for four multiplier 1052a to 1052d through the modulated symbol of convergent-divergent, the latter also receives respectively standardization eigenvector four elements with .Its standardization eigenvector value of each multiplier 1052 use be multiplied by its modulated symbol through convergent-divergent to provide through preregulated code element.Multiplier 1052a respectively offers buffer/multiplexer 1070a to 1070d four through preregulated code element subflow to 1052d.

For 48 data subbands, each buffer/multiplexer 1070 is from sending subband wave beam control processor 1040a to 1040k reception pilot frequency code element with through preregulated code element, pilot tone and multiplexed through preregulated code element and null value, and provide one to send code element stream x for a transmit antennas for each code-element period _i(n).The follow-up OFDM modulation of each transmission code element stream as mentioned above.

The processing of wave beam control model is described in further detail in the common U.S. Patent application of transferring the possession of, this patent was submitted on August 27th, 2002, sequence number is 10/228,393, is entitled as " Beam-Steering and Beam-Formingfor Wideband MIMO Systems ".System also can be designed to support beam forming pattern, uses whereby eigenvector instead of standardized vector to send data flow in main eigenmodes.

The framing of 4.PHY frame

Figure 11 A illustrates an embodiment of framing unit 808, and framing unit 808 for carrying out framing to the data of each FCH/RCH grouping before sending data processor to carry out subsequent treatment.This framing function is for the upper message sending of BCH, FCCH and RACH and bypass.Framing unit is that each FCH/RCH grouping generates an integer PHY frame, and wherein for embodiment described here, each PHY frame strides across 6 OFDM code elements.

For diversity and wave beam control model, only use a space channel or broadband eigenmodes for transfer of data.The speed of this pattern is known, can calculate the information bit that may send in the pay(useful) load of each PHY frame.For space multiplexing mode, can use multiple space channels for transfer of data.Because the speed of each space channel is known, therefore for all space channels, can calculate the information bit sending in the pay(useful) load of each PHY frame.

As shown in Figure 11 A, the information bit of each FCH/RCH grouping (is labeled as to i ₁i ₂i ₃i ₄...) offer CRC maker 1102 and multiplexer 1104 in framing unit 808.Bit in header (if there is) and pay(useful) load field that CRC maker 1102 is each PHY frame generates a crc value, and CRC bit is offered to multiplexer 1104.Multiplexer 1104 receives information bit, CRC bit, preamble bit and filling bit (for example null value), and provides these bits based on PHY control frame signal with correct order, as shown in Figure 6.By directly providing information bit by multiplexer 1104, can bypass framing function.Through framing and not the bit of framing (be labeled as d ₁d ₂d ₃d ₄...) be provided for disarrangement device 810.

5. upset

In one embodiment, the data bit of each transmission channel is in encoder multilated.Upset data randomization, the complete one or complete zero long sequence forming is not sent.This can reduce the peak value of OFDM waveform to the variation of average power.Upset can be omitted one or more transmission channels, and also can optionally be enabled and forbid.

Figure 11 A also illustrates an embodiment of disarrangement device 810.In this embodiment, disarrangement device 810 is realized a Generator polynomial:

G(x)＝x ⁷+x ⁴+x (22)

Also can use other Generator polynomial, this within the scope of the invention.

As shown in Figure 11 A, seven delay element 1112a that disarrangement device 810 comprises order coupling are to 1112g.For each clock cycle, adder 1114 is carried out mould 2 to preserve in delay element 1112d and 1112g two bits and is added, and a upset bit is offered to delay element 1112a.

Through framing/the not bit (d of framing ₁d ₂d ₃d ₄) being provided for adder 1116, the corresponding bit of upsetting of adder 1116 use is to each bit d _ncarry out mould 2 and add, to the bit q through upsetting is provided _n.Disarrangement device 810 provides once the sequence that upsets bit, is labeled as q ₁q ₂q ₃q ₄....

In the beginning of each tdd frame, the initial condition of disarrangement device (being the content of delay element 1112a to 1112g) is set as the non-zero number of one 7 bits.As shown in BCH message, three highest significant positions (MSB) (being that delay element 1112e is to 1112f) are always set as one (" 1 "), and four least significant bits (LSB) are set as tdd frame counter.

6. coding/brachymemma

In one embodiment, use single base code before transmission, data to be encoded.This base code is that a code rate generates coded-bit.All other code rates (as shown in Table 25) that system is supported can by or repeated encoding bit or or brachymemma coded-bit obtain.

Figure 11 B illustrates an embodiment of the encoder 812 of the base code that can realize system.In this embodiment, base code is that speed is 1/2, limited length is the convolutional encoding of 7 (K=7), and maker is 133 and 171 (octal system).

In encoder 812, multiplexer 1120 receives and multiplexed bit and tail bit (for example null value) through upsetting.Encoder 812 also comprises that six delay element 1122a of order coupling are to 1122f.Four adder 1124a are coupled to 1124d also order, and are used for realizing the first maker (133).Similarly, four adder 1126a are coupled to 1126d also order, and are used for realizing the second maker (171).As shown in Figure 11 B, adder is further coupled to delay element in the mode that realizes two makers 133 and 171.

Offering the first delay element 1122a and adder 1124a and 1126a through the bit of upsetting.For each clock cycle, adder 1124a carries out moulds 2 to 1124d to preserve four previous bits in the bit arriving and delay element 1122b, 1122c, 1122e and 1122f and adds, to provide the first coded-bit for this clock cycle.Similarly, adder 1126a carries out moulds 2 to 1126d to preserve four previous bits in the bit arriving and delay element 1122a, 1122b, 1122c and 1122f and adds, to provide the second coded-bit for this clock cycle.The coded-bit that the first maker generates is marked as a ₁a ₂a ₃a ₄..., the coded-bit that the second maker generates is marked as b ₁b ₂b ₃b ₄....Then, multiplexer 1128 receives two coded bit streams from two makers, and they are multiplexed into single encoded bit stream, and the latter is marked as a ₁b ₁a ₂b ₂a ₃b ₃a ₄b ₄....For each bit q through upsetting _n, generate two coded-bit a _nand b _n, this produces code rate 1/2.

Figure 11 B also illustrates an embodiment who can the base bit rate based on 1/2 generates repetition/brachymemma unit 814 that other code rate uses.In unit 814, be provided for repetitive 1132 and brachymemma 1134 from the coded-bit of the speed 1/2 of encoder 812.Repetitive 1132 repeats each speed 1/2 coded-bit once, to obtain efficient coding speed 1/4.The coded-bit of some speed 1/2 is deleted based on specific brachymemma pattern in brachymemma unit 1134, to the code rate of expectation is provided.

Table 30 is listed the exemplary brachymemma pattern that can be used for the various code rates that system supports.Also can use other brachymemma pattern, this within the scope of the invention.

Table 30

In order to obtain code rate k/n, the coded-bit that brachymemma unit 1134 is every group of 2k speed 1/2 receiving from encoder 812 provides n coded-bit.Like this, from every group of 2k coded-bit, delete 2k-n coded-bit.To carry out mark by zero brachymemma pattern from every group of bit of deleting.For example, for obtaining code rate 7/12, always in every group of 14 coded-bits of own coding device 812, delete two bits, the bit of deleting is the 8th and the 14th coded-bit in group, as brachymemma pattern " 11111110111110 " institute mark.If the code rate of expecting is 1/2, do not carry out brachymemma.

Multiplexer 1136 receives from repetitive 1132 with from the coded bit stream of brachymemma unit 1134.Then, if expect that code rate is 1/4, multiplexer 1136 provides the coded-bit from repetitive 1132, if expect that code rate is 1/2 or higher, multiplexer 1136 provides the coded bit stream from brachymemma unit 1134.

Except above-mentioned coding and brachymemma pattern, also can use other coding and brachymemma pattern, this is within the scope of the invention.For example, can encode to data by Turbo code, piece coding, some other yards or their combination in any.Equally, for different transmission channels can use different encoding schemes.For example, can use conventional coding for Common transport channel, can use Turbo coding for dedicated transmission channel.

7. interweave

The coded-bit that be sent out in one embodiment, is interleaved at 48 data intersubbands.For diversity and wave beam control model, between all data subbands, send and the coded bit stream that interweaves.For space multiplexing mode, nearly on four space channels, can send nearly four coded bit streams.Interweave and can carry out independently for each space channel, each coded bit stream is interleaved between all data subbands of the space channel for sending this bit stream.Table 29 illustrates the exemplary coded-bit-allocation of subbands interweaving that can be used for all transmission modes.

In one embodiment, interweave in interval each, carry out and interweave at all 48 data intersubbands.For this embodiment, in a stream, every group of 48 coded-bits are all expanded on 48 data subbands, so that frequency diversity to be provided.48 coded-bits in every group can be assigned to index 0 to 47.Each coded-bit index is associated with a corresponding subband.All coded-bits with a particular index are all sent out on relevant subband.For example, the first coded-bit (index is 0) in every group is sent out on subband-26, the second coded-bit (index is 14) is sent out on subband 1, and the 3rd coded-bit (index is 2) is sent out on subband-17, and the rest may be inferred.This interleaving scheme can be used for diversity mode, wave beam control model and space multiplexing mode.Other interleaving scheme for spatial reuse is described below.

Interweave or or can carry out in time in addition.For example, after interweaving between data subband, the coded-bit of each subband can further be interweaved (for example, on a PHY frame or a PDU) so that time diversity to be provided.For space multiplexing mode, also can on multiple space channels, carry out and interweave.

In addition, can on the dimension of QAM code element, adopt and interweave, the coded-bit that makes to form QAM code element be mapped as the different bit positions of QAM code element.

8. symbol mapped

Table 31 illustrates the symbol mapped of each modulation scheme that system supports.For each modulation scheme (except BPSK), the bit of half is mapped as homophase (I) component, and second half bit is mapped as orthogonal (Q) component.

In one embodiment, can define based on Gray (Gray) mapping a signal group of stars for each supported modulation scheme.According to gray mappings, the consecutive points (in I and Q component) in a signal group of stars only differ a bit position.Gray mappings is that situation about more may make mistakes has reduced number of bit errors, and error situation is mapped as near position tram corresponding to receiving symbol, in this situation, only can mistake receive a coded-bit.

Table 31

The I of the each modulation scheme shown in table 31 and Q value one normalization factor k _normconvergent-divergent, makes the average power of all signaling points in a coherent signal group of stars equal one.Also can use the quantized value of the normalization factor of supported modulation scheme.So the modulated symbol s in a signal specific group of stars has following form:

s＝(I+jQ)·K _norm，

Wherein I and Q are the values of a signal group of stars in table 31.

For given PDU, being modulated at may be different between PDU, and the multiple space channels that use for transfer of data also may be different.For example, for BCH PDU, can use different modulation schemes for beacon pilot frequency, MIMO pilot tone and BCH message.

9. the processing of space multiplexing mode

For space multiplexing mode, a PDU can be sent out on multiple space channels.Can carry out deal with data by various schemes, for sending on multiple space channels.Two specific processing schemes of space multiplexing mode are described below.

In the first processing scheme, carry out coding and brachymemma by each space channel, to be that each space channel is realized the code rate of expecting.The N that transfer of data will be used _eindividual space channel is arranged from being up to minimum reception SNR.First encode the data of whole PDU to obtain speed 1/2 coded bit stream.Then brachymemma coded-bit is to be that each space channel obtains the code rate of expecting.

For N _eindividual space channel, brachymemma can be carried out with order, from the space channel of best (i.e. the highest SNR) to the poorest (being minimum SNR).Particularly, brachymemma unit is first for the optimal spatial channel with the highest reception SNR is carried out brachymemma.In the time having generated the coded-bit of correct number for optimal spatial channel, brachymemma is just carried out for having time inferior good space channel of high reception SNR in brachymemma unit.This process continues, until all N _etill the coded-bit of individual space channel has all generated.The order of brachymemma is to receive SNR to minimum receive SNR from maximum, and the specific coding speed no matter each space channel uses is how many.

For the example shown in table 28, first with the base code of speed 1/2,3456 information bits that will send in total PHY frame are encoded, to obtain 6912 coded-bits.Front 3168 coded-bits carry out brachymemma to obtain 2304 coded-bits by the brachymemma pattern of code rate 11/16, and the latter provides in the PHY of the first space channel frame.Then carry out brachymemma to obtain 1728 coded-bits by the brachymemma pattern of code rate 3/4 to following 2592 coded-bits, the latter provides in the PHY of second space channel frame.Then then 864 coded-bits are to obtain 576 coded-bits to carry out brachymemma by the brachymemma pattern of code rate 3/4, and the latter provides in the PHY frame of the 3rd space channel.Then last 288 coded-bits that carry out brachymemma PHY frame by the brachymemma pattern of code rate 1/2 to be to obtain 288 coded-bits, and the latter in the end provides in the PHY frame of a space channel.These four independent PHY frames are further processed and are sent out on four space channels.Then carry out in a similar manner the brachymemma of next total PHY frame.The first processing scheme can realize with the transmission data processor 710b in Fig. 9 A.

In the second processing scheme, be encoding and brachymemma to carrying out of subband.In addition, coding and brachymemma are in the whole selected space channel cocycle of every pair of subband.

Figure 11 C illustrates a block diagram, and it has illustrated the transmission data processor 710d that realizes the second processing scheme.Encoder 812 is to carrying out the convolutional encoding of speed 1/2 from the bit through upsetting of disarrangement device 810.Each space channel is assigned to a special speed, and this special speed is associated with the particular combinations of code rate and modulation scheme, as shown in Table 25.Make b _mrepresent number of coded bits for each modulated symbol of space channel m (or ground of equal value, the number of coded bits sending) on each data subband of space channel m, r _mthe code rate that representation space channel m uses.B _mvalue depend on the group of stars size of the modulation scheme that space channel m uses.Particularly, for BPSK, QPSK, 16-QAM, 64-QAM and 256-QAM, b _mequal respectively 1,2,4,6 and 8.

Encoder 812 provides speed 1/2 coded bit stream to demultiplexer 816, and demultiplexer 816 resolves into the coded bit stream multichannel receiving four subflows of four space channels.Multichannel decomposition makes front 4b ₁r ₁individual coded-bit is sent to the buffer 813a of space channel 1, then 4b ₂r ₂individual coded-bit is sent to the buffer 813b of space channel 2, and the rest may be inferred.Whenever demultiplexer 816 is during all four space channel cocycles one time, each buffer 813 just receives 4b _mr _mindividual coded-bit.For each cycle, always total $b_{\mathrm{total}}=\underset{m=1}{\overset{4}{\mathrm{\Σ}}}4b_m{r}_m$ The coded-bit of individual speed 1/2 is provided for four buffer 813a to 813d.Therefore, for every b _totalindividual coded-bit, demultiplexer 816 circulates through whole four positions of four space channels, b _totalit is the number of coded bits that uses whole four space channels to send on a pair of subband.

Once the 4b of each buffer 813 use correlation space channels _mr _mindividual coding chip is filled, and the coded-bit in just can brachymemma buffer is to obtain the code rate of this space channel.Due to 4b _mr _mthe coded-bit of individual speed 1/2 has striden across an integer truncated human cyclin of each brachymemma pattern, therefore, after the brachymemma of each space channel m, in fact provides 2b _mindividual coded-bit.Then, the 2b of each space channel _mindividual coded-bit just distributes (or interweaving) on data subband.

In one embodiment, once in one group of 6 subband, each space channel is carried out and interweaved.Coded-bit after the brachymemma of each space channel can sequentially be arranged as c _i, for i=0,1,2 ....For each space channel maintains a counter C _mso that every group of 6b that brachymemma unit is provided for this space channel _mindividual coded-bit is counted.For example,, for b _m=2 QPSK, the coded-bit c providing for brachymemma unit ₀to c ₁₁, counter can be set as C _m=0, for coded-bit c afterwards ₁₂to c ₂₃, can be set as C _m=1, the rest may be inferred.The Counter Value C of space channel m _mcan be expressed as:

C _m＝ i/(6b _m) mod8 (23)

In order to determine coded-bit c _ibe assigned to which subband, determine first as follows the code index of coded-bit:

Bit index=(i mod 6)+6C _m(24)

Then, bit index use table 29 is mapped to corresponding subband.

For upper example, first group of 6 coded-bit c ₀to c ₅be associated with bit index 0 to 5 respectively, second group of 6 coded-bit c ₆to c ₁₁also be associated to 5 with bit index 0 respectively.Shown in table 29, coded-bit c ₀and c ₆can be mapped to subband-26, coded-bit c ₁and c ₇can be mapped to subband 1, the rest may be inferred.Then start spatial manipulation for these first group of 6 subband.The 3rd group of 6 coded-bit c ₁₂to c ₁₇(C _m=1) be associated with bit index 6 to 11 respectively, the 4th group of 6 coded-bit c ₁₈to c ₂₃also be associated to 11 with bit index 6 respectively.Coded-bit c ₁₂and c ₁₈can be mapped to subband-25, coded-bit c ₁₃and c ₁₉can be mapped to subband 2, the rest may be inferred.Then for 6 subbands of this next group start spatial manipulation.

Numeral 6 in formula (24) comes from the group of 6 subbands to be carried out and interweaves.(mod8) computing in formula (23) comes from for 48 data subbands 8 groups that interweave.Because each circulation of the demultiplexer 816 shown in Figure 11 C produces enough coded-bits and fill two subbands of each broadband eigenmodes, therefore need altogether the OFDM code element that 24 cycles are each space channel that 48b is provided _mindividual coded-bit.

Once in the group of 6 subbands, interweave and can reduce processing delay.Particularly, once every group of 6 subbands are available, can start spatial manipulation.

In other embodiments, once can be at N _bin the group of individual subband, carry out and interweave for each space channel, wherein N _bcan be that arbitrary integer is (for example, for interweaving on whole 48 data subbands, N _bcan equal 48).

VI. calibration

For TDD system, down link and up link are shared identical frequency band in the mode of time division duplex.In this situation, there is height correlation in half between down link and the channel response of up link.This is correlated with and can be used to simplify channel estimating and spatial manipulation.For TDD system, each subband of supposing wireless link is reciprocal.Namely, if h(k) represent for subband k the channel response matrix from antenna array A to antenna array B, reciprocal channel mean joint from antenna array B to antenna array A by h(k) transposition provides, h ^t(k).

But the response (gain and phase place) of access point place sending and receiving chain is general different from the response of user terminal place sending and receiving chain.Can carry out calibration and determine frequency response poor of the sending/receiving chain at access point and user terminal place, and make up this difference, make down link and the uplink response through calibrating can be according to representing each other.For example, for example, once calibrate and made up sending/receiving chain, the dominant vector that just can use the tolerance of a link (down link) to derive another link (up link).

" effectively " down link and uplink channel responses h _dn(k) and h _up(k) comprise the response of the available sending and receiving chain in access point and user terminal place, and be expressed as:

H _dn(k)＝ R _ut(k) H(k) T _ap(k)， k∈K， (25)

H _up(k)＝ R _ap(k) H ^T(k) T _ut(k)，k∈K，

Wherein t _ap(k) and r _ap(k) be N _ap× N _apdiagonal matrix, its be for subband k, respectively with the N of access point place _apthe transmission chain of root antenna and the item of the complex gain that receive chain is associated;

t _ut(k) and r _ut(k) be N _ut× N _utdiagonal matrix, its be for subband k, respectively with the N of user terminal place _utthe transmission chain of root antenna and the item of the complex gain that receive chain is associated; And

h(k) be the N of down link _ut× N _apchannel response matrix.

Two formula in combinatorial formula collection (25), obtain following relational expression:

H _up(k) K _ut(k)＝( H _dn(k) K _ap(k)) ^T， k∈K， (26)

Wherein ${\underset{\‾}{K}}_{\mathrm{ut}}\left(k\right)={\underset{\‾}{T}}_{\mathrm{ut}}^{-1}\left(k\right){\underset{\‾}{R}}_{\mathrm{ut}}\left(k\right)$ And ${\underset{\‾}{K}}_{\mathrm{ap}}\left(k\right)={\underset{\‾}{T}}_{\mathrm{ap}}^{-1}\left(k\right){\underset{\‾}{R}}_{\mathrm{ap}}\left(k\right).$

The left side of formula (26) represents the channel response of " reality " calibration in up link, and the right represents the transposition of the channel response of " reality " calibration on down link.As shown in formula (26), apply respectively diagonal matrix to effective down link and uplink channel responses k _ap(k) and k _ut(k), can represent with transposition each other the channel response of the calibration of down link and up link.(the N of access point _ap× N _ap) diagonal matrix is receive chain response r _ap(k) with the response of transmission chain t _ap(k) ratio ( ${\underset{\‾}{K}}_{\mathrm{ap}}\left(k\right)=\frac{{\underset{\‾}{R}}_{\mathrm{ap}}\left(k\right)}{{\underset{\‾}{T}}_{\mathrm{ap}}\left(k\right)}$ ), wherein this ratio one by one element draw.Similarly, (the N of user terminal _ut× N _ut) diagonal matrix is receive chain response r _ut(k) with the response of transmission chain t _ut(k) ratio.

Matrix k _ap(k) and k _ut(k) comprise the value of the difference that can make up access point and user terminal place sending/receiving chain.So this can be represented by the channel response of another link the channel response of a link, as shown in formula (26).

Can carry out calibration and determine matrix k _ap(k) and k _ut(k).Generally speaking, real channel response h(k) and sending/receiving chain response be unknown, can not accurately or easily determine them.But the pilot tone based on sending in down link and up link is estimated effective down link and uplink channel responses respectively h _dn(k) and h _up(k), as described below.Then as described below, can estimate based on down link and uplink channel responses with carry out derivational matrix k _ap(k) and k _ut(k) estimation, the latter is called correction matrix with .Matrix with comprise the correction factor of the difference that can make up access point and user terminal place sending/receiving chain.

" calibration " down link and uplink channel responses that user terminal and access point observe are expressed as:

${\underset{\‾}{H}}_{\mathrm{cdn}}\left(k\right)={\underset{\‾}{H}}_{\mathrm{dn}}\left(k\right){\underset{\‾}{\overset{^}{K}}}_{\mathrm{ap}}\left(k\right),k\∈K,---\left(27\right)$

${\underset{\‾}{H}}_{\mathrm{cup}}\left(k\right)={\underset{\‾}{H}}_{\mathrm{up}}\left(k\right){\underset{\‾}{\overset{^}{K}}}_{\mathrm{ut}}\left(k\right),k\∈K,$

Wherein h _cdn ^t(k) and h _cup(k) be the estimation of the channel response expression formula of " reality " calibration in formula (26).Use the expression formula of formula (26) to carry out two formula in combinatorial formula collection (27), can obtain ${\underset{\‾}{H}}_{\mathrm{cup}}\left(k\right)\≈{\underset{\‾}{H}}_{\mathrm{cdn}}^T\left(k\right).$ Relational expression ${\underset{\‾}{H}}_{\mathrm{cup}}\left(k\right)\≈{\underset{\‾}{H}}_{\mathrm{cdn}}^T\left(k\right)$ Accuracy depend on matrix with accuracy, the latter generally depends on again that down link and uplink channel responses estimate with quality.

Calibration can be carried out by various schemes.For clear, a specific calibration program is described below.In order to carry out calibration, first user terminal obtains timing and the frequency of access point based on the upper beacon pilot frequency sending of BCH.Then, user terminal sends a message so that the calibration process of beginning and access point on RACH.Calibration can be carried out concurrently with registration/checking.

On the frequency band of generally noting at great majority due to the frequency response of access point and user terminal place sending/receiving chain, be level and smooth, therefore the phase/gain of sending/receiving chain is poor can characterize with a small amount of subband.Calibration can to 4,8,16,48 or the subband of some other quantity carry out, this quantity is specified in the message that is sent out to start calibration.Calibration also can be carried out pilot subbands.The calibration constants of clearly not carrying out the subband of calibration on it can be by calculating the subband interpolation of calibration.For clear, be below assumed to all data subbands and all carry out calibration.

For calibration, access point distributes the time of sufficient amount on RACH to user terminal, add a message so that transmission has the up link MIMO pilot tone of enough durations.The duration of up link MIMO pilot tone may be depended on the sub band number of carrying out thereon calibration.For example, if four subbands are carried out to calibration, 8 OFDM code elements can be that enough, more subbands may need more (for example 20) OFDM code element.Total transmitted power is generally fixed, if therefore send MIMO pilot tone on a small amount of subband, can be the transmitted power of each use a greater number of these subbands, and the SNR of each subband is very high.On the contrary, if send MIMO pilot tone on a large amount of subbands, can use for each subband the transmitted power of small amount, the SNR of each subband is very poor.If the SNR of each subband is enough high, for MIMO pilot tone sends more OFDM code element, and in these OFDM code elements of receiver place integration to be the higher total SNR of this subband acquisition.

Then, user terminal sends a MIMO pilot tone on RCH, and access point carrys out the estimation for each data subband derivation efficient uplink channel response with it .Uplink channel responses is estimated be quantized (be for example quantified as the complex values of 12 bits, have homophase (I) and orthogonal (Q) component) and be sent to user terminal.

User terminal also derives for each data subband the estimation of active downlink channel response based on the upper downlink mimo pilot tone sending of BCH .Obtaining effective up link and downlink channel response estimation for all data subbands with after, user terminal is determined correction factor for each data subband with they are access in respectively a little and user terminal uses.Can be updating vector only be defined as and comprise diagonal element, and updating vector only be defined as and comprise diagonal element.

Correction factor can derive in every way, comprises by matrix ratio and calculating and MMSE calculating.These two kinds of computational methods are all described in further detail below.Also can use other computational methods, this within the scope of the invention.

1. matrix ratio calculates

In order to estimate according to effective down link and uplink channel responses with determine updating vector with first for each data subband calculates (a N _ut× N _ap) matrix c(k), as follows:

$\underset{\‾}{C}\left(k\right)=\frac{{\underset{\‾}{\overset{^}{H}}}_{\mathrm{up}}^T\left(k\right)}{{\underset{\‾}{\overset{^}{H}}}_{\mathrm{dn}}\left(k\right)},k\∈K,---\left(28\right)$

Wherein ratio one by one element draw.Therefore c(k) each element can calculate as follows:

$c_{i,j}\left(k\right)=\frac{{\hat{h}}_{\mathrm{upi},j}\left(k\right)}{{\hat{h}}_{\mathrm{dni},j}\left(k\right)},i=\{1...N_{\mathrm{ut}}\},j=\{1...N_{\mathrm{ap}}\},---\left(29\right)$

Wherein be (i, j) individual (OK, row) element, be (i, j) individual element, c _{i, j}(k) be c(k) (i, j) individual element.

So, the updating vector of access point equal c(k) average of standardization row.First use first element in a line to N in this row _apeach of individual element is carried out convergent-divergent, thereby right c(k) the column criterion of often advancing.Like this, if ${\underset{\‾}{c}}_i\left(k\right)=[c_{i,1}\left(k\right)/c_{i,1}\left(k\right)...c_{i,j}\left(k\right)/c_{i,1}\left(k\right)...c_{{i,N}_{\mathrm{ap}}}\left(k\right)/c_{i,1}\left(k\right)]$ Be c(k) i is capable, standardized row can be expressed as:

${\underset{\‾}{\tilde{c}}}_i\left(k\right)=[c_{i,1}\left(k\right)/c_{i,1}\left(k\right)...c_{i,j}\left(k\right)/c_{i,1}\left(k\right)...c_{i,N_{\mathrm{ap}}}\left(k\right)/c_{i,1}\left(k\right)]---\left(30\right)$

So the average of standardization row is N _utindividual standardization row sum is divided by N _ut, be expressed as follows:

${\widehat{\underset{\‾}{k}}}_{\mathrm{ap}}\left(k\right)=\frac{1}{N_{\mathrm{ut}}}\underset{i=1}{\overset{N_{\mathrm{ut}}}{\mathrm{\Σ}}}{\widetilde{\underset{\‾}{c}}}_i\left(k\right),k\∈K---\left(31\right)$

Due to standardization, therefore first element be one.

The updating vector of user terminal equal c(k) average reciprocal of standardization row.First use vector j element (mark K _{ap, j, j}(k) be) the each element in row is carried out to convergent-divergent, thus right c(k) every row carry out standardization.Like this, if ${\underset{\‾}{c}}_j\left(k\right)={[c_{1,j}\left(k\right)...c_{N_{\mathrm{ut}},j}\left(k\right)]}^T$ Be c(k) j is capable, standardized row can be expressed as:

So the average reciprocal of standardization row is N _apthe sum reciprocal of individual standardization row is divided by N _ap, be expressed as follows:

Wherein standardization row inverse carry out by element.

2.MMSE calculates

Calculate correction factor for MMSE with estimate from effective down link and uplink channel responses with middle derivation, thereby mean square error (MSE) minimum between the downlink channel response and the uplink channel responses of calibration that make to calibrate.This condition can be expressed as follows:

$\min {|{\left({\underset{\‾}{\overset{^}{H}}}_{\mathrm{dn}}\left(k\right){\underset{\‾}{\overset{^}{K}}}_{\mathrm{ap}}\left(k\right)\right)}^T-\left({\underset{\‾}{\overset{^}{H}}}_{\mathrm{up}}\left(k\right){\underset{\‾}{\overset{^}{K}}}_{\mathrm{ut}}\left(k\right)\right)|}^2,k\∈K,---\left(34\right)$

Also can write:

$\min {|{\underset{\‾}{\overset{^}{K}}}_{\mathrm{ap}}\left(k\right){\underset{\‾}{\overset{^}{H}}}_{\mathrm{dn}}^T\left(k\right)-{\underset{\‾}{\overset{^}{H}}}_{\mathrm{up}}\left(k\right){\underset{\‾}{\overset{^}{K}}}_{\mathrm{ut}}\left(k\right)|}^2,k\∈K,$

Wherein because pair of horns matrix, therefore ${\underset{\‾}{\overset{^}{K}}}_{\mathrm{ap}}^T\left(k\right)={\underset{\‾}{\overset{^}{K}}}_{\mathrm{ap}}\left(k\right).$

Formula (34) suffers restraints: first element be set as one ( ${\underset{\‾}{\overset{^}{K}}}_{\mathrm{ap},\mathrm{0,0}}\left(k\right)=1$ )。If there is no this constraint, can obtain common solution, matrix with all elements be all set as zero.In formula (34), first obtain matrix y(k): $\underset{\‾}{Y}\left(k\right)={\underset{\‾}{\overset{^}{K}}}_{\mathrm{ap}}\left(k\right){\underset{\‾}{\overset{^}{H}}}_{\mathrm{dn}}^T\left(k\right)-{\underset{\‾}{\overset{^}{H}}}_{\mathrm{up}}\left(k\right){\underset{\‾}{\overset{^}{K}}}_{\mathrm{ut}}\left(k\right).$ Then be matrix y(k) N _apn _utindividual each obtain absolute value square.

For the subband of each appointment is carried out MMSE and calculates to obtain the correction factor of this subband with

The MMSE that a subband is described below calculates.For simplicity, omit in the following description subband index k.Equally for simplicity, downlink channel response is estimated element be marked as { a _ij, uplink channel responses is estimated element be marked as { b _ij, matrix diagonal element be marked as { u _i, matrix diagonal element be marked as { v _i, wherein i={1...N _apand j={1...N _ut.

Can rewrite mean square error from formula (34), as follows:

$\mathrm{MSE}=\underset{j=1}{\overset{N_{\mathrm{ut}}}{\mathrm{\Σ}}}\underset{i=1}{\overset{N_{\mathrm{ap}}}{\mathrm{\Σ}}}{|a_{\mathrm{ij}}{u}_i-b_{\mathrm{ij}}{v}_j|}^2,---\left(35\right)$

Same constraints is u ₁=1.Go out and partial derivative is made as to zero by the local derviation of getting formula (35) with reference to u and v, thereby obtaining least mean-square error.The result of these computings is following formulary:

$\underset{j=1}{\overset{N_{\mathrm{ut}}}{\mathrm{\Σ}}}(a_{\mathrm{ij}}{u}_i-b_{\mathrm{ij}}{v}_j)\·a_{\mathrm{ij}}^{*}=0,i\∈\{2...N_{\mathrm{ap}}\},---\left(36a\right)$

$\underset{i=1}{\overset{N_{\mathrm{ap}}}{\mathrm{\Σ}}}(a_{\mathrm{ij}}{u}_i-b_{\mathrm{ij}}{v}_j)\·b_{\mathrm{ij}}^{*}=0,j\∈\{1...N_{\mathrm{ut}}\}.---\left(36b\right)$

In formula (36a), u ₁=1, therefore in this situation, there is no partial derivative, index i gets N from 2 _ap.

Formulary (36a) and (36b) in (N _ap+ N _ut-1) set of individual formula can represent more easily with matrix form, as follows:

Ay＝ z， (37)

Wherein

$\underset{\‾}{A}=\left[\begin{array}{cccccccc}\underset{j=1}{\overset{N_{\mathrm{ut}}}{\mathrm{\Σ}}}{\left|a_{2j}\right|}^2& 0& \·\·\·& 0& -b_{21}{a}_{21}^{*}& \·\·\·& & {-b}_{2N_{\mathrm{ap}}}{a}_{2N_{\mathrm{ut}}}^{*}\\ 0& \underset{j=1}{\overset{N_{\mathrm{ut}}}{\mathrm{\Σ}}}{\left|a_{3j}\right|}^2& 0& \·\·\·& \·\·\·& \·\·\·& & \·\·\·\\ \·\·\·& 0& \·\·\·& 0& & & & \\ 0& \·\·\·& 0& \underset{j=1}{\overset{N_{\mathrm{ut}}}{\mathrm{\Σ}}}{\left|a_{N_{\mathrm{ap}}j}\right|}^2& -b_{N_{\mathrm{ap}}1}{a}_{N_{\mathrm{ap}}1}^{*}& & & -b_{N_{\mathrm{ap}}{N}_{\mathrm{ut}}{a}_{N_{\mathrm{ap}}{N}_{\mathrm{ut}}}^{*}}\\ -a_{21}{b}_{21}^{*}& \·\·\·& & -a_{N_{\mathrm{ap}}1}{b}_{N_{\mathrm{ap}}1}^{*}& \underset{i=1}{\overset{N_{\mathrm{ap}}}{\mathrm{\Σ}}}{\left|b_{i1}\right|}^2& 0& \·\·\·& 0\\ \·\·\·& \·\·\·& & & 0& \underset{i=1}{\overset{N_{\mathrm{ap}}}{\mathrm{\Σ}}}{\left|b_{i2}\right|}^2& 0& \·\·\·\\ & & & & \·\·\·& 0& \·\·\·& 0\\ -a_{2N_{\mathrm{ut}}}{b}_{2N_{\mathrm{ut}}}^{*}& \·\·\·& & -a_{N_{\mathrm{ap}}{N}_{\mathrm{ut}}}{b}_{N_{\mathrm{ap}}{N}_{\mathrm{ut}}}^{*}& 0& \·\·\·& 0& \underset{i=1}{\overset{N_{\mathrm{ap}}}{\mathrm{\Σ}}}{\left|b_{i{N}_{\mathrm{ut}}}\right|}^2\end{array}\right]$

$\underset{\‾}{y}=\left[\begin{array}{c}{u}_2\\ u_3\\ \·\·\·\\ u_{N_{\mathrm{ap}}}\\ v_1\\ v_2\\ \·\·\·\\ v_{N_{\mathrm{ut}}}\end{array}\right]$ $\underset{\‾}{z}=\left[\begin{array}{c}0\\ 0\\ \·\·\·\\ 0\\ a_{11}{b}_{11}^{*}\\ a_{12}{b}_{12}^{*}\\ \·\·\·\\ a_{1N_{\mathrm{ut}}}{b}_{1N_{\mathrm{ut}}}^{*}\end{array}\right]$

Matrix acomprise (N _ap+ N _ut-1) OK, front N _ap-1 row is corresponding to the N in formulary (36a) _ap-1 formula, last N _utrow is corresponding to the N in formulary (36b) _utindividual formula.Particularly, matrix athe first row generate from formulary (36a) according to i=2, the second row generates according to i=3, the rest may be inferred.Matrix an _aprow generates from formulary (36b) according to j=1, and the rest may be inferred, and last column is according to j=N _utgenerate.As implied above, matrix aevery and vectorial zevery can be based on matrix with in every and draw.

Correction factor is included in vector yin, draw as follows:

y＝ A ^-1 z (38)

The result that MMSE calculates is the correction matrix of the mean square error minimum in down link and the uplink channel responses that makes to calibrate with , as shown in formula (34).Due to matrix with estimate based on down link and uplink channel responses with obtain therefore correction matrix with quality depend on channel estimating with quality.MIMO pilot tone is average to obtain at receiver place with estimation more accurately.

Calculate the correction matrix obtaining based on MMSE with generally good than calculating based on matrix ratio the correction matrix obtaining.Very little and tolerance noise is especially true can make channel gain greatly demote in the situation that at some channel gains.

3. in rear calculating

Can determine a pair of updating vector for each data subband with .Because adjacent subband may be correlated with, therefore calculate simplification.For example, can instead of carry out calculating for each subband for every n subband, wherein n can be determined by the intended response of sending/receiving chain.Be less than if total data and pilot subbands and carry out calibration, the correction factor of " not calibration " subband can be by obtaining for " calibration " subband interpolation correction factor.

Also can be respectively access point and user terminal derivation updating vector with various other calibration programs with .But such scheme can be that access point is derived " compatible " updating vector in the time that calibration is carried out by different user terminals.

After derivation, user terminal is the updating vector of all data subbands beam back access point.If access point is calibrated (for example, by other user terminal), upgrade current updating vector with the updating vector newly receiving.Like this, if access point uses updating vector send MIMO pilot tone, user terminal is determined new updating vector from this MIMO pilot tone , the updating vector after upgrading is current and new the amassing of updating vector, ${\underset{\‾}{\overset{^}{k}}}_{\mathrm{ap}3}\left(k\right)={\underset{\‾}{\overset{^}{k}}}_{\mathrm{ap}1}\left(k\right)\·{\underset{\‾}{\overset{^}{k}}}_{\mathrm{ap}2}\left(k\right),$ Wherein multiplication is by element ground execution one by one.Then, the updating vector after renewal can be access in a use, until they are upgraded again.

Updating vector with can be derived by same user terminal or different user terminals.In one embodiment, the updating vector after renewal is defined as ${\underset{\&OverBar;}{\overset{^}{k}}}_{\mathrm{ap}3}\left(k\right)={\underset{\&OverBar;}{\overset{^}{k}}}_{\mathrm{ap}1}\left(k\right)\&CenterDot;{\underset{\&OverBar;}{\overset{^}{k}}}_{\mathrm{ap}2}\left(k\right),$ Wherein multiplication is by element ground execution one by one.In another embodiment, the updating vector after renewal can be redefined into ${\underset{\&OverBar;}{\overset{^}{k}}}_{\mathrm{ap}3}\left(k\right)={\underset{\&OverBar;}{\overset{^}{k}}}_{\mathrm{ap}1}\left(k\right)\&CenterDot;{\underset{\&OverBar;}{\overset{^}{k}}}_{\mathrm{ap}2}^{\mathrm{\&alpha;}}\left(k\right),$ Wherein α is used to provide average weighted factor (for example 0 < α < 1).If it is not frequent that calibration is upgraded, α may be best close to 1.If calibration is upgraded frequently but made an uproar, less α value can be better.Then, the updating vector after renewal be access in a use, until they are upgraded again.

Access point and user terminal use their corresponding updating vectors with , or corresponding correction matrix with (for k ∈ K) convergent-divergent modulated symbol before transmission, as described below.Formula (27) illustrates down link and the uplink channel of the calibration that user terminal and access point observe.

VII. spatial manipulation

Making up after difference in sending/receiving chain carrying out calibration, can be the spatial manipulation at TDD system simplification access point and user terminal place.As mentioned above, the downlink channel response of calibration is ${\underset{\&OverBar;}{H}}_{\mathrm{cdn}}\left(k\right)={\underset{\&OverBar;}{H}}_{\mathrm{dn}}\left(k\right){\underset{\&OverBar;}{\overset{^}{K}}}_{\mathrm{ap}}\left(k\right).$ The uplink channel responses of calibration is ${\underset{\&OverBar;}{H}}_{\mathrm{cup}}\left(k\right)={\underset{\&OverBar;}{H}}_{\mathrm{up}}\left(k\right){\underset{\&OverBar;}{\overset{^}{K}}}_{\mathrm{ut}}\left(k\right)\&ap;{\left({\underset{\&OverBar;}{H}}_{\mathrm{dn}}\left(k\right){\underset{\&OverBar;}{\overset{^}{K}}}_{\mathrm{ap}}\left(k\right)\right)}^T.$

1. process in up link space

The uplink channel responses matrix of calibration h _cup(k) singular value decomposition can be expressed as:

${\underset{\&OverBar;}{H}}_{\mathrm{cup}}\left(k\right)={\underset{\&OverBar;}{U}}_{\mathrm{ap}}\left(k\right)\underset{\&OverBar;}{\mathrm{\&Sigma;}}\left(k\right){\underset{\&OverBar;}{V}}_{\mathrm{ut}}^H\left(k\right),k\&Element;K,---\left(39\right)$

Wherein u _ap(k) be h _cup(k) (the N of left side eigenvector _ap× N _ap) unitary matrix;

∑(k) be h _cup(k) (the N of singular value _ap× N _ut) diagonal matrix; And

v _ut(k) be h _cup(k) (the N of the right eigenvector _ut× N _ut) unitary matrix.

Correspondingly, the downlink channel response matrix of calibration h _cdn(k) singular value decomposition can be expressed as:

${\underset{\&OverBar;}{H}}_{\mathrm{cdn}}\left(k\right)={\underset{\&OverBar;}{V}}_{\mathrm{ut}}^{*}\left(k\right)\underset{\&OverBar;}{\mathrm{\&Sigma;}}\left(k\right){\underset{\&OverBar;}{U}}_{\mathrm{ap}}^T\left(k\right),k\&Element;K---\left(40\right)$

Matrix v _ut ^*(k) and u _ap ^*(k) be respectively h _cdn(k) matrix of the left side and the right eigenvector.As shown in formula (39) and (40) and based on above description, the matrix of the left side of a link and the right eigenvector is respectively the complex conjugate of the right of another link and the matrix of left side eigenvector.Matrix v _ut(k), v _ut ^*(k), v _ut ^t(k) and v _ut ^h(k) be matrix v _ut(k) multi-form, matrix u _ap(k), u _ap ^*(k), u _ap ^tand U (k) _ap ^h(k) be also matrix u _ap(k) multi-form.For simplicity, the matrix of indication in the following description u _ap(k) and v _ut(k) also refer to their various other forms.Matrix u _ap(k) and v _ut(k) be used for carrying out spatial manipulation by access point and user terminal respectively, and identified by their subscript.Eigenvector is conventionally also referred to as " control " vector.

The MIMO pilot tone that user terminal can send based on access point is estimated the downlink channel response of calibration.Then, user terminal can be estimated the downlink channel response of calibration carry out singular value decomposition (for k ∈ K), to obtain diagonal matrix matrix with left side eigenvector v _ut ^*(k).This singular value decomposition can be given: ${\underset{\&OverBar;}{\overset{^}{H}}}_{\mathrm{cdn}}\left(k\right)={\underset{\&OverBar;}{\overset{^}{V}}}_{\mathrm{ut}}^{*}\left(k\right)\underset{\&OverBar;}{\overset{^}{\mathrm{\&Sigma;}}}\left(k\right){\underset{\&OverBar;}{\overset{^}{U}}}_{\mathrm{ap}}^T\left(k\right),$ Wherein the cap " ^ " on each matrix represents that it is the estimation of actual matrix.

Similarly, the MIMO pilot tone that access point can send based on user terminal is estimated the uplink channel responses of calibration.Then, access point can be estimated the uplink channel responses of calibration carry out singular value decomposition (for k ∈ K), to obtain diagonal matrix matrix with left side eigenvector u _ap ^*(k).This singular value decomposition can be given: ${\underset{\&OverBar;}{\overset{^}{H}}}_{\mathrm{cup}}\left(k\right)={\underset{\&OverBar;}{\overset{^}{U}}}_{\mathrm{ap}}\left(k\right)\underset{\&OverBar;}{\overset{^}{\mathrm{\&Sigma;}}}\left(k\right){\underset{\&OverBar;}{\overset{^}{V}}}_{\mathrm{ut}}^H\left(k\right).$

One (N _ut× N _ut) matrix f _ut(k) can be defined as:

${\underset{\&OverBar;}{F}}_{\mathrm{ut}}\left(k\right)={\underset{\&OverBar;}{\overset{^}{K}}}_{\mathrm{ut}}\left(k\right){\underset{\&OverBar;}{\overset{^}{V}}}_{\mathrm{ut}}\left(k\right),k\&Element;K---\left(41\right)$

In the time of activity, user terminal is estimated the downlink channel of calibration continuously and the matrix of left side eigenvector , the latter is used for upgrading matrix f _ut(k).

User terminal uses matrix f _ut(k) carry out spatial manipulation for wave beam control and space multiplexing mode.For space multiplexing mode, the transmission vector of each subband x _up(k) can be expressed as:

x _up(k)＝ F _ut(k) S _up(k)， k∈K， (42)

Wherein s _up(k) be a data vector, it has will be at the N of subband k _sthe N sending in individual eigenmodes _sindividual code element;

f _ut(k) in replacement formula (15) v(k), for simplicity, in formula (42), omitted for realize channel reversion by g(k) the signal convergent-divergent carrying out;

x _up(k) be the transmission vector of the up link of subband k.

At access point place, the reception vector of ul transmissions r _up(k) can be expressed as:

${\underset{\&OverBar;}{r}}_{\mathrm{up}}\left(k\right)={\underset{\&OverBar;}{H}}_{\mathrm{up}}\left(k\right){\underset{\&OverBar;}{x}}_{\mathrm{up}}\left(k\right)+{\underset{\&OverBar;}{n}}_{\mathrm{up}}\left(k\right),k\&Element;K,---\left(43\right)$

$={\underset{\&OverBar;}{H}}_{\mathrm{up}}\left(k\right){\underset{\&OverBar;}{\overset{^}{K}}}_{\mathrm{ut}}\left(k\right){\underset{\&OverBar;}{\overset{^}{V}}}_{\mathrm{ut}}\left(k\right){\underset{\&OverBar;}{s}}_{\mathrm{up}}\left(k\right)+{\underset{\&OverBar;}{n}}_{\mathrm{up}}\left(k\right)$

$\&ap;{\underset{\&OverBar;}{\overset{^}{H}}}_{\mathrm{cup}}\left(k\right){\underset{\&OverBar;}{\overset{^}{V}}}_{\mathrm{ut}}\left(k\right){\underset{\&OverBar;}{s}}_{\mathrm{up}}\left(k\right)+{\underset{\&OverBar;}{n}}_{\mathrm{up}}\left(k\right)$

$={\underset{\&OverBar;}{\overset{^}{U}}}_{\mathrm{ap}}\left(k\right)\underset{\&OverBar;}{\overset{^}{\mathrm{\&Sigma;}}}\left(k\right){\underset{\&OverBar;}{\overset{^}{V}}}_{\mathrm{ut}}^H\left(k\right){\underset{\&OverBar;}{\overset{^}{V}}}_{\mathrm{ut}}\left(k\right){\underset{\&OverBar;}{s}}_{\mathrm{up}}\left(k\right)+{\underset{\&OverBar;}{n}}_{\mathrm{up}}\left(k\right)$

$={\underset{\&OverBar;}{\overset{^}{U}}}_{\mathrm{ap}}\left(k\right)\underset{\&OverBar;}{\overset{^}{\mathrm{\&Sigma;}}}\left(k\right){\underset{\&OverBar;}{s}}_{\mathrm{up}}\left(k\right)+{\underset{\&OverBar;}{n}}_{\mathrm{up}}\left(k\right)$

Wherein r _up(k) be the reception vector of up link subband k; And

n _up(k) be the Additive White Gaussian Noise (AWGN) of subband k.

Formula (43) uses following relational expression: ${\underset{\&OverBar;}{H}}_{\mathrm{up}}\left(k\right){\underset{\&OverBar;}{\overset{^}{K}}}_{\mathrm{ut}}\left(k\right)={\underset{\&OverBar;}{H}}_{\mathrm{cup}}\left(k\right)\&ap;{\underset{\&OverBar;}{\overset{^}{H}}}_{\mathrm{cup}}\left(k\right)$ With ${\underset{\&OverBar;}{\overset{^}{H}}}_{\mathrm{cup}}\left(k\right)={\underset{\&OverBar;}{\overset{^}{U}}}_{\mathrm{ap}}\left(k\right)\underset{\&OverBar;}{\overset{^}{\mathrm{\&Sigma;}}}\left(k\right){\underset{\&OverBar;}{\overset{^}{V}}}_{\mathrm{ut}}^H\left(k\right).$ As shown in formula (43), at access point place, the ul transmissions receiving by convert Hou Zheshi the matrix of left side eigenvector with the diagonal matrix of singular value composition convergent-divergent.

User terminal uses matrix f _ut(k) in up link, send a controlled benchmark.Controlled benchmark is the pilot transmission in a broadband eigenmodes that uses wave beam control or beam forming, describes in detail below.At access point place, the controlled benchmark of up link (in the time there is no noise) receiving is approximately like this, the controlled benchmark that access point can send based on user terminal draws unitary matrix and diagonal matrix estimation.Can draw with various estimation techniques the estimation of unitary matrix and diagonal matrix.In one embodiment, in order to draw estimation, for the subband k of broadband eigenmodes m, the reception vector of controlled benchmark r _m(k) first with the complex conjugate p that is the pilot tone OFDM code element that sends of controlled benchmark ^*(k) multiply each other.Describe the generation of controlled benchmark and pilot tone OFDM code element below in detail.For each broadband eigenmodes, its result is in multiple controlled reference symbol upper integrals that receive, to draw estimation, broadband eigenmodes m through the left side of convergent-divergent eigenvector.Because eigenvector has unit power, therefore can the received power based on controlled benchmark estimate in singular value (or σ _m(k)), the received power of controlled benchmark can be measured for each subband of each broadband eigenmodes.

In another embodiment, carry out the reception vector based on controlled benchmark by MMSE technology r _m(k) draw estimation.

Controlled benchmark can be sent out for a broadband eigenmodes in arbitrary given code-element period, and is used for again drawing for each subband of this broadband eigenmodes the estimation of an eigenvector.Like this, receive the estimation that draws an eigenvector in a unitary matrix in a function given code-element period in office.Owing to drawing the estimation of multiple eigenvectors of unitary matrix in different code-element periods, and due to the noise in transfer path and other degradation source, the eigenvector of therefore estimating for unitary matrix may be non-orthogonal.If estimated eigenvector is then used in the spatial manipulation of transfer of data on other link, any error of the orthogonality of these estimated eigenvectors all can cause the cross-talk between eigenmodes, and this can make performance degradation.

In one embodiment, the eigenvector of estimating for each unitary matrix is forced orthogonal.The orthogonal of eigenvector can be realized by various technology, such as QR Factorization, least mean-square error calculating, polarization decomposing etc.QR Factorization is a matrix m ^t(having non-orthogonal row) resolves into an orthogonal matrix q _fwith a upper triangular matrix r _f.Matrix q _ffor m ^trow form orthogonal basis. r _fdiagonal element exist q _fin the direction of respective column, provide m ^tthe length of the component of each row.Matrix q _fcan be used for the spatial manipulation on down link.Matrix q _fwith r _fcan be used for deriving for up link the matched filter matrix strengthening.QR Factorization can be carried out by the whole bag of tricks, comprises Gram-Schmidt process, householder transformation etc.

Also the technology that can estimate with other unitary matrix and diagonal matrix based on controlled benchmark, this within the scope of the invention.

Therefore the controlled benchmark that, access point can send based on user terminal is estimated with both, and without right carry out singular value decomposition.

From the standardization matched filter matrix of the ul transmissions of user terminal m _ap(k) can be expressed as:

${\underset{\&OverBar;}{M}}_{\mathrm{ap}}\left(k\right)={\underset{\&OverBar;}{\overset{^}{\mathrm{\&Sigma;}}}}^{-1}\left(k\right){\underset{\&OverBar;}{\overset{^}{U}}}_{\mathrm{ap}}^H\left(k\right),k\&Element;K.---\left(44\right)$

Access point place can be expressed as for the matched filtering of ul transmissions:

${\underset{\&OverBar;}{\overset{^}{s}}}_{\mathrm{up}}\left(k\right)={\underset{\&OverBar;}{M}}_{\mathrm{ap}}\left(k\right){\underset{\&OverBar;}{r}}_{\mathrm{up}}\left(k\right)$

$={\underset{\&OverBar;}{\overset{^}{\mathrm{\&Sigma;}}}}^{-1}\left(k\right){\underset{\&OverBar;}{\overset{^}{U}}}_{\mathrm{ap}}^H\left(k\right)({\underset{\&OverBar;}{\overset{^}{U}}}_{\mathrm{ap}}\left(k\right)\underset{\&OverBar;}{\overset{^}{\mathrm{\&Sigma;}}}\left(k\right){\underset{\&OverBar;}{s}}_{\mathrm{up}}\left(k\right)+{\underset{\&OverBar;}{n}}_{\mathrm{up}}\left(k\right)),k\&Element;K,---\left(45\right)$

$={\underset{\&OverBar;}{s}}_{\mathrm{up}}\left(k\right)+{\underset{\&OverBar;}{\overset{~}{n}}}_{\mathrm{up}}\left(k\right)$

Wherein it is the modulation symbol vector being sent by user terminal for space multiplexing mode s _up(k) estimation.For wave beam control model, only use matrix m _ap(k) a line provides a symbol estimation for transfer of data eigenmodes used

2. down link spatial manipulation

For down link, access point uses (a N _ap× N _ap) matrix f _ap(k) carry out spatial manipulation.This matrix can be expressed as:

${\underset{\&OverBar;}{F}}_{\mathrm{ap}}\left(k\right)={\underset{\&OverBar;}{\overset{^}{K}}}_{\mathrm{ap}}\left(k\right){\underset{\&OverBar;}{\overset{^}{U}}}_{\mathrm{ap}}^{*}\left(k\right),k\&Element;K.---\left(46\right)$

Correction matrix derive and be sent back to access point by user terminal between alignment epoch.Matrix the controlled benchmark that can send in up link based on user terminal draws.

For space multiplexing mode, the transmission vector of the down link of each data subband x _dn(k) can be expressed as:

x _dn(k)＝ F _ap(k) S _dn(k)， k∈K， (47)

Wherein x _dn(k) be to send vector, s _dn(k) be the data vector of down link, equally for simplicity and omit by g(k) for realizing the channel signal convergent-divergent carrying out that reverses.

At user terminal place, the reception vector of downlink transmission r _dn(k) can be expressed as:

${\underset{\&OverBar;}{r}}_{\mathrm{dn}}\left(k\right)={\underset{\&OverBar;}{H}}_{\mathrm{dn}}\left(k\right){\underset{\&OverBar;}{x}}_{\mathrm{dn}}\left(k\right)+{\underset{\&OverBar;}{n}}_{\mathrm{dn}}\left(k\right)$

$={\underset{\&OverBar;}{H}}_{\mathrm{dn}}\left(k\right){\underset{\&OverBar;}{\overset{^}{K}}}_{\mathrm{ap}}\left(k\right){\underset{\&OverBar;}{\overset{^}{U}}}_{\mathrm{ap}}^{*}\left(k\right){\underset{\&OverBar;}{s}}_{\mathrm{dn}}\left(k\right)+{\underset{\&OverBar;}{n}}_{\mathrm{dn}}\left(k\right)$

$\&ap;{\underset{\&OverBar;}{\overset{^}{H}}}_{\mathrm{cdn}}\left(k\right){\underset{\&OverBar;}{\overset{^}{U}}}_{\mathrm{ap}}^{*}\left(k\right){\underset{\&OverBar;}{s}}_{\mathrm{dn}}\left(k\right)+{\underset{\&OverBar;}{n}}_{\mathrm{dn}}\left(k\right)$

$={\underset{\&OverBar;}{\overset{^}{V}}}_{\mathrm{ut}}^{*}\left(k\right)\underset{\&OverBar;}{\overset{^}{\mathrm{\&Sigma;}}}\left(k\right){\underset{\&OverBar;}{\overset{^}{U}}}_{\mathrm{ap}}^T\left(k\right){\underset{\&OverBar;}{\overset{^}{U}}}_{\mathrm{ap}}^{*}\left(k\right){\underset{\&OverBar;}{s}}_{\mathrm{dn}}\left(k\right)+{\underset{\&OverBar;}{n}}_{\mathrm{dn}}\left(k\right))$

$={\underset{\&OverBar;}{\overset{^}{V}}}_{\mathrm{ut}}^{*}\left(k\right)\underset{\&OverBar;}{\overset{^}{\mathrm{\&Sigma;}}}\left(k\right){\underset{\&OverBar;}{s}}_{\mathrm{dn}}\left(k\right)+{\underset{\&OverBar;}{n}}_{\mathrm{dn}}\left(k\right),k\&Element;K---\left(48\right)$

As shown in formula (48), at user terminal place, the downlink transmission warp receiving conversion, be the matrix of left side eigenvector with the diagonal matrix of singular value composition carry out convergent-divergent.

${\underset{\&OverBar;}{M}}_{\mathrm{ut}}\left(k\right)={\underset{\&OverBar;}{\overset{^}{\mathrm{\&Sigma;}}}}^{-1}\left(k\right){\underset{\&OverBar;}{\overset{^}{V}}}_{\mathrm{ut}}^T\left(k\right),k\&Element;K---\left(49\right)$

As mentioned above, by the downlink channel response of calibration is estimated carry out singular value decomposition, user terminal can be derived diagonal matrix matrix with left side eigenvector

So the matched filtering that user terminal place is downlink transmission to carry out can be expressed as:

${\underset{\&OverBar;}{\overset{^}{s}}}_{\mathrm{dn}}\left(k\right)={\underset{\&OverBar;}{M}}_{\mathrm{ut}}\left(k\right){\underset{\&OverBar;}{r}}_{\mathrm{dn}}\left(k\right)$

$={\underset{\&OverBar;}{\overset{^}{\mathrm{\&Sigma;}}}}^{-1}\left(k\right){\underset{\&OverBar;}{\overset{^}{V}}}_{\mathrm{ut}}^T\left(k\right)({\underset{\&OverBar;}{\overset{^}{V}}}_{\mathrm{ut}}^T\left(k\right)\underset{\&OverBar;}{\overset{^}{\mathrm{\&Sigma;}}}\left(k\right){\underset{\&OverBar;}{s}}_{\mathrm{dn}}\left(k\right)+{\underset{\&OverBar;}{n}}_{\mathrm{dn}}\left(k\right)),k\&Element;K---\left(50\right)$

$={\underset{\&OverBar;}{s}}_{\mathrm{dn}}\left(k\right)+{\underset{\&OverBar;}{\overset{~}{n}}}_{\mathrm{dn}}\left(k\right)$

3. the spatial manipulation of access point and user terminal

Due to reciprocal channel and the calibration of TDD system, therefore the spatial manipulation at access point and user terminal place is all simplified.Access point summed up by table 32 and user terminal place is the spatial manipulation that data input and data output carries out.

Table 32

The spatial manipulation of data receiver is also referred to as matched filtering.

Due to the existence of reciprocal channel, therefore it is user terminal the right eigenvector of (for send) and both matrixes of left side eigenvector of (for receiving).Similarly, it is access point the right eigenvector of (for send) and both matrixes of left side eigenvector of (for receiving).The downlink channel response that singular value decomposition need to be only calibration by user terminal is estimated carry out, to draw with .The controlled benchmark that access point can send based on user terminal is derived with , and without uplink channel responses is estimated carry out singular value decomposition.Access point and user terminal may be owing to being derivation and used different means therefore to there is multi-form matrix .In addition the matrix that, access point is derived based on controlled benchmark the matrix general and user terminal is derived by singular value decomposition different.For simplicity, in above-mentioned derivation, do not demonstrate these differences.

4. wave beam control

For specific channel condition, only in a broadband eigenmodes, sending data is preferably, and this broadband eigenmodes is generally best or main broadband eigenmodes.This situation may be: the reception SNR of all other broadband eigenmodes is enough poor, thereby by using all available transmitted powers can realize improved performance in the eigenmodes of main broadband.

Transfer of data in a broadband eigenmodes can realize with beam forming or wave beam control.For beam forming, generally use the eigenvector of main broadband eigenmodes or (after sequence, or first row) modulated symbol is carried out to spatial manipulation, wherein k ∈ K.For wave beam control, generally use one group of " standardized " (or saturated) eigenvector of main broadband eigenmodes or modulated symbol is carried out to spatial manipulation, wherein k ∈ K.For clear, the wave beam control of up link is described below.For up link, each eigenvector of main broadband eigenmodes element may have different sizes, wherein k ∈ K.Like this, each subband also may have different sizes through preregulated code element, described through preregulated code element by the eigenvector of the modulated symbol of subband k and subband k element multiply each other and draw.Thereby the transmission vector of every antenna all may have different sizes, described each send vector comprise a given transmitting antenna total data subband through preregulated code element.For example, if the transmitted power of every transmit antennas is restricted the restriction of power amplifier (due to), beam forming uses the gross power that every antenna can be used by halves.

Wave beam control is only used the eigenvector of main broadband eigenmodes phase information, k ∈ K, and each eigenvector is carried out to standardization, makes all elements in eigenvector have equal size.The standardization eigenvector of subband k can be expressed as:

${\underset{\&OverBar;}{\overset{~}{v}}}_{\mathrm{ut}}\left(k\right)={\left[\begin{array}{cccc}{\mathrm{Ae}}^{j{\mathrm{\&theta;}}_1\left(k\right)}& {\mathrm{Ae}}^{j{\mathrm{\&theta;}}_2\left(k\right)}& \&CenterDot;\&CenterDot;\&CenterDot;& {\mathrm{Ae}}^{j{\mathrm{\&theta;}}_{N_{\mathrm{ut}}}\left(k\right)}\end{array}\right]}^T,---\left(51\right)$

Wherein A is a constant (for example A=1); And

θ _i(k) be the phase place of the subband k of antenna i, provide as follows:

${\mathrm{\&theta;}}_i\left(k\right)=\&angle;{\hat{v}}_{\mathrm{ut},1,i}\left(k\right)={\tan }^{-1}\left(\frac{\mathrm{Im}\left\{{\hat{v}}_{\mathrm{ut},1,i}\left(k\right)\right\}}{\mathrm{Re}\left\{{\hat{v}}_{\mathrm{ut},1,i}\left(k\right)\right\}}\right).---\left(52\right)$

As shown in formula (52), vector in the phase place of each element from eigenvector respective element in draw (to be θ _i(k) from draw, wherein

5. uplink beam control

The spatial manipulation that user terminal carries out for wave beam control in up link can be expressed as:

${\underset{\&OverBar;}{\overset{~}{x}}}_{\mathrm{up}}\left(k\right)={\underset{\&OverBar;}{\overset{^}{K}}}_{\mathrm{ut}}{\underset{\&OverBar;}{\overset{~}{v}}}_{\mathrm{ut}}\left(k\right)s_{\mathrm{up}}\left(k\right),k\&Element;K,---\left(53\right)$

Wherein s _up(k) be the modulated symbol that will send on subband k; And

for wave beam control, the transmission vector of subband k.

As shown in formula (53), the standardization control vector of each subband n _utindividual element may have equal size but may have different phase places.

Access point place is that the ul transmissions that wave beam control receives can be expressed as:

${\underset{\&OverBar;}{\overset{~}{r}}}_{\mathrm{up}}\left(k\right)={\underset{\&OverBar;}{H}}_{\mathrm{up}}\left(k\right){\underset{\&OverBar;}{\overset{~}{x}}}_{\mathrm{up}}\left(k\right)+{\underset{\&OverBar;}{n}}_{\mathrm{up}}\left(k\right),k\&Element;K,---\left(54\right)$

$={\underset{\&OverBar;}{H}}_{\mathrm{up}}\left(k\right){\underset{\&OverBar;}{\overset{^}{K}}}_{\mathrm{ut}}\left(k\right){\underset{\&OverBar;}{\overset{~}{v}}}_{\mathrm{ut}}\left(k\right)s_{\mathrm{up}}\left(k\right)+{\underset{\&OverBar;}{n}}_{\mathrm{up}}\left(k\right)$

$={\underset{\&OverBar;}{H}}_{\mathrm{cup}}\left(k\right){\underset{\&OverBar;}{\overset{~}{v}}}_{\mathrm{ut}}\left(k\right)s_{\mathrm{up}}\left(k\right)+{\underset{\&OverBar;}{n}}_{\mathrm{up}}\left(k\right)$

Wherein for wave beam control, the reception vector of the up link of subband k.

Use the matched filter row vector of the ul transmissions of wave beam control can be expressed as:

${\underset{\&OverBar;}{\overset{~}{m}}}_{\mathrm{ap}}\left(k\right)={\left({\underset{\&OverBar;}{H}}_{\mathrm{cup}}\left(k\right){\underset{\&OverBar;}{\overset{~}{v}}}_{\mathrm{ut}}\left(k\right)\right)}^H,k\&Element;K---\left(55\right)$

Matched filter vector can draw as described below.Access point place is used the receiving uplink of wave beam control to transmit the spatial manipulation (being matched filtering) of carrying out can be expressed as:

${\hat{s}}_{\mathrm{up}}\left(k\right)={\widetilde{\mathrm{\&lambda;}}}_{\mathrm{up}}^{-1}\left(k\right){\underset{\&OverBar;}{\overset{~}{m}}}_{\mathrm{ap}}\left(k\right){\underset{\&OverBar;}{\overset{~}{r}}}_{\mathrm{up}}\left(k\right)$

$={\widetilde{\mathrm{\&lambda;}}}_{\mathrm{up}}^{-1}\left(k\right){\left({\underset{\&OverBar;}{H}}_{\mathrm{cup}}\left(k\right){\underset{\&OverBar;}{\overset{~}{v}}}_{\mathrm{ut}}\left(k\right)\right)}^H({\underset{\&OverBar;}{H}}_{\mathrm{cup}}\left(k\right){\underset{\&OverBar;}{\overset{~}{v}}}_{\mathrm{ut}}\left(k\right)s_{\mathrm{up}}\left(k\right)+{\underset{\&OverBar;}{n}}_{\mathrm{up}}\left(k\right)),k\&Element;K,---\left(56\right)$

$=s_{\mathrm{up}}\left(k\right)+{\tilde{n}}_{\mathrm{up}}\left(k\right)$

Wherein ${\widetilde{\mathrm{\&lambda;}}}_{\mathrm{up}}\left(k\right)={\left({\underset{\&OverBar;}{H}}_{\mathrm{cup}}\left(k\right){\underset{\&OverBar;}{\overset{~}{v}}}_{\mathrm{ut}}\left(k\right)\right)}^H\left({\underset{\&OverBar;}{H}}_{\mathrm{cup}}\left(k\right){\underset{\&OverBar;}{\overset{~}{v}}}_{\mathrm{ut}}\left(k\right)\right)$ ( be inner product with its conjugate transpose),

the modulated symbol S being sent in up link by user terminal _up(k) estimation, and it is the noise of reprocessing.

6. downlink beamforming control

The spatial manipulation that access point carries out for wave beam control on down link can be expressed as:

${\underset{\&OverBar;}{\overset{~}{x}}}_{\mathrm{dn}}\left(k\right)={\underset{\&OverBar;}{\overset{^}{K}}}_{\mathrm{ap}}{\underset{\&OverBar;}{\overset{~}{u}}}_{\mathrm{ap}}\left(k\right)s_{\mathrm{dn}}\left(k\right),k\&Element;K,---\left(57\right)$

Wherein the standardization eigenvector of subband k, its eigenvector based on main broadband eigenmodes and generate, as above for described in up link.

Use the matched filter row vector of the downlink transmission of wave beam control can be expressed as:

${\underset{\&OverBar;}{\overset{~}{m}}}_{\mathrm{ut}}\left(k\right)={\left({\underset{\&OverBar;}{H}}_{\mathrm{cdn}}\left(k\right){\underset{\&OverBar;}{\overset{~}{u}}}_{\mathrm{ap}}\left(k\right)\right)}^H,k\&Element;K.---\left(58\right)$

The spatial manipulation (being matched filtering) that user terminal place carries out the downlink transmission receiving can be expressed as:

${\hat{s}}_{\mathrm{dn}}\left(k\right)={\widetilde{\mathrm{\&lambda;}}}_{\mathrm{dn}}^{-1}\left(k\right){\underset{\&OverBar;}{\overset{~}{m}}}_{\mathrm{ut}}\left(k\right){\underset{\&OverBar;}{\overset{~}{r}}}_{\mathrm{dn}}\left(k\right)$

$={\widetilde{\mathrm{\&lambda;}}}_{\mathrm{dn}}^{-1}\left(k\right){\left({\underset{\&OverBar;}{H}}_{\mathrm{cdn}}\left(k\right){\underset{\&OverBar;}{\overset{~}{u}}}_{\mathrm{ap}}\left(k\right)\right)}^H({\underset{\&OverBar;}{H}}_{\mathrm{cdn}}\left(k\right){\underset{\&OverBar;}{\overset{~}{u}}}_{\mathrm{ap}}\left(k\right)s_{\mathrm{up}}\left(k\right)+{\underset{\&OverBar;}{n}}_{\mathrm{dn}}\left(k\right)),k\&Element;K,---\left(59\right)$

$=s_{\mathrm{dn}}\left(k\right)+{\tilde{n}}_{\mathrm{dn}}\left(k\right)$

Wherein ${\widetilde{\mathrm{\&lambda;}}}_{\mathrm{dn}}\left(k\right)={\left({\underset{\&OverBar;}{H}}_{\mathrm{cdn}}\left(k\right){\underset{\&OverBar;}{\overset{~}{u}}}_{\mathrm{ap}}\left(k\right)\right)}^H\left({\underset{\&OverBar;}{H}}_{\mathrm{cdn}}\left(k\right){\underset{\&OverBar;}{\overset{~}{u}}}_{\mathrm{ap}}\left(k\right)\right)$ ( be inner product with its conjugate transpose).

7. by the channel spatial manipulation of carrying out of reversing

For up link, the transmission vector of space multiplexing mode x _up(k) can be exported as by user terminal:

${\underset{\&OverBar;}{x}}_{\mathrm{up}}\left(k\right)={\underset{\&OverBar;}{\overset{^}{K}}}_{\mathrm{ut}}\left(k\right){\underset{\&OverBar;}{\overset{^}{V}}}_{\mathrm{ut}}\left(k\right)\underset{\&OverBar;}{G}\left(k\right){\underset{\&OverBar;}{s}}_{\mathrm{up}}\left(k\right),k\&Element;K,---\left(60\right)$

Wherein g(k) be the diagonal matrix of the gain of above-mentioned channel reversion.Formula (60) is similar to formula (15), except using replace v(k) in addition. element be provided for the multiplier 952 in the beam-shaper 950 of Fig. 9 B.

For up link, the transmission vector of wave beam control model can be exported as by user terminal:

${\underset{\&OverBar;}{\overset{~}{x}}}_{\mathrm{up}}\left(k\right)={\underset{\&OverBar;}{\overset{^}{K}}}_{\mathrm{ut}}\left(k\right){\underset{\&OverBar;}{\overset{~}{v}}}_{\mathrm{ut}}\left(k\right)\tilde{g}\left(k\right)s_{\mathrm{up}}\left(k\right),k\&Element;K,---\left(61\right)$

Wherein be a vector, it has four elements to have identical size, but phase place is the eigenvector based on main eigenmodes and draw.Vector can be similar to above such derivation the described in formula (16) and (17).Gain realize channel reversion, and can be similar to above such derivation the described in formula (18) to (20), except being formula (20) use ${\widetilde{\mathrm{\&lambda;}}}_1\left(k\right)={\underset{\&OverBar;}{\overset{~}{v}}}_{\mathrm{ut}}^H\left(k\right){\underset{\&OverBar;}{\overset{^}{H}}}_{\mathrm{cup}}^H\left(k\right){\underset{\&OverBar;}{\overset{^}{H}}}_{\mathrm{cup}}\left(k\right){\underset{\&OverBar;}{\overset{~}{v}}}_{\mathrm{ut}}\left(k\right)$ In addition. element be provided for the multiplier 1052 in the wave beam control unit 1050 of Figure 10 B.

For down link, the transmission vector of space multiplexing mode x _dn(k) can be exported as by access point:

${\underset{\&OverBar;}{x}}_{\mathrm{dn}}\left(k\right)={\underset{\&OverBar;}{\overset{^}{K}}}_{\mathrm{ap}}\left(k\right){\underset{\&OverBar;}{\overset{^}{U}}}_{\mathrm{ap}}^{*}\left(k\right)\underset{\&OverBar;}{G}\left(k\right){\underset{\&OverBar;}{s}}_{\mathrm{dn}}\left(k\right),k\&Element;K.---\left(62\right)$

Formula (62) is similar to formula (15), except replacing v(k) use in addition. element can be provided for the multiplier 952 in beam-shaper 950 in Fig. 9 B.

For down link, the transmission vector of wave beam control model can be exported as by access point:

${\underset{\&OverBar;}{\overset{~}{x}}}_{\mathrm{dn}}\left(k\right)={\underset{\&OverBar;}{\overset{^}{K}}}_{\mathrm{ap}}\left(k\right){\underset{\&OverBar;}{\overset{~}{u}}}_{\mathrm{ap}}\left(k\right)\tilde{g}\left(k\right)s_{\mathrm{dn}}\left(k\right),k\&Element;K,---\left(63\right)$

Wherein be a vector, it has four elements, and they have equal size, but their phase place is based on main eigenmodes draw.Gain realize channel reversion, and can be with above such derivation the described in formula (18) to (20), except being formula (20) use ${\widetilde{\mathrm{\&lambda;}}}_1\left(k\right)={\underset{\&OverBar;}{\overset{~}{u}}}_{\mathrm{ap}}^h\left(k\right){\underset{\&OverBar;}{\overset{^}{H}}}_{\mathrm{cdn}}^H\left(k\right){\underset{\&OverBar;}{\overset{^}{H}}}_{\mathrm{cdn}}\left(k\right){\underset{\&OverBar;}{\overset{~}{u}}}_{\mathrm{ap}}\left(k\right)$ In addition. element be provided for the multiplier 1052 in Figure 10 B medium wave bundle control unit 1050.

VIII. pilot configuration

For MIMO wlan system provides a pilot configuration, make access point and user terminal can carry out timing and frequency acquisition, channel estimating and correct other required function of System Operation.Table 33 is listed four class pilot tones and their Short Description of an exemplary pilot structure.

Table 33-pilot type

Controlled benchmark and controlled pilot tone are synonyms.

In one embodiment, pilot configuration comprises: the carrier pilot that (1) sends for down link-beacon pilot frequency, MIMO pilot tone, controlled benchmark and access point, and (2) are for up link-MIMO pilot tone, controlled benchmark and the carrier signal that sent by user terminal.

Downlink beacon pilot tone and MIMO pilot tone send (as shown in Figure 5A) in each tdd frame on BCH.User terminal can use beacon pilot frequency to carry out timing and frequency acquisition and Doppler's estimation.User terminal can come by MIMO pilot tone: (1) draws the estimation of downlink mimo channel, (2) for ul transmissions derives controlled vector (if supporting wave beam control or space multiplexing mode), and (3) are downlink transmission induced matching filter.The controlled benchmark of down link can be used for carrying out channel estimating by specific user terminal.

The controlled benchmark of up link is sent by each active user terminals of supporting wave beam control or space multiplexing mode, and can be used for by access point: (1) is downlink transmission derivation dominant vector, and (2) are ul transmissions induced matching filter.Conventionally, controlled benchmark is only sent by the user terminal of supporting wave beam control and/or space multiplexing mode.Benchmark sends object, and no matter whether it is correctly controlled (for example, due to poor channel estimating).Namely, because gating matrix is diagonal angle, therefore benchmark also becomes orthogonal by every transmit antennas.If user terminal is calibrated, it can use vector in (for k ∈ K) main eigenmodes on RACH, send a controlled benchmark, wherein for main eigenmodes row.If user terminal is not calibrated, it can be with vectorial ${\underset{\&OverBar;}{v}}_{\mathrm{ut},p}\left(k\right)={\left[\begin{array}{cccc}{e}^{j{\mathrm{\&theta;}}_1\left(k\right)}& e^{j{\mathrm{\&theta;}}_2\left(k\right)}& e^{j{\mathrm{\&theta;}}_3\left(k\right)}& e^{j{\mathrm{\&theta;}}_{N_{\mathrm{ut}}}\left(k\right)}\end{array}\right]}^T$ (for k ∈ K) sends a pilot tone on RACH.The vector of each subband v _{ut, p}(k) comprise N _utindividual STOCHASTIC CONTROL coefficient, their phase theta _i(k) may select according to-pseudo-random process, wherein i ∈ 1,2 ... N _ut.Owing to only having N _utrelative phase between individual control coefrficient just has relation, and therefore the phase place of the first control coefrficient can be made as to zero (is θ ₁(k)=0).Other N _utthe phase place of-1 control coefrficient may change in the time of each access attempts, makes each control coefrficient with 360 °/N _{θ i}interval covered whole 360 degree, wherein N _{θ i}n _utfunction.Use RACH in beam modes before calibration time, when each RACH attempts to dominant vector v _{ut, p}(k) N _utthe phase perturbation of individual element makes user terminal not make for all access attempts the dominant vector of damaging.Can be not support the user terminal of wave beam control and/or space multiplexing mode to send MIMO, or send MIMO by these user terminals.

Before user terminal is directly communicated by letter with access point, access point is not known the channel of arbitrary user terminal.In the time that user wishes to send data, the MIMO pilot tone that first it send based on access point is estimated channel.( )

$\underset{\&OverBar;}{x}\left(k\right)={\underset{\&OverBar;}{\overset{^}{K}}}_{\mathrm{ut}}\left(k\right)\&CenterDot;{\underset{\&OverBar;}{\overset{^}{v}}}_{\mathrm{ut},1}\left(k\right)\&CenterDot;p\left(k\right),k\&Element;K^{\&prime;},---\left(64\right)$

Dominant vector to estimate through the uplink channel responses of calibration the matrix of the right eigenvector first row, wherein ${\underset{\&OverBar;}{\overset{^}{V}}}_{\mathrm{ut}}\left(k\right)=\left[\begin{array}{cccc}{\underset{\&OverBar;}{\overset{^}{v}}}_{\mathrm{ut},1}\left(k\right)& {\underset{\&OverBar;}{\overset{^}{v}}}_{\mathrm{ut},2}\left(k\right)& {\underset{\&OverBar;}{\overset{^}{v}}}_{\mathrm{ut},3}\left(k\right)& {\underset{\&OverBar;}{\overset{^}{v}}}_{\mathrm{ut},4}\left(k\right)\end{array}\right],$ be i row.More than supposition in singular value and row arrange with said sequence.

The second code element of the controlled benchmark that user terminal sends in the leader of RACH comprises the data rate indicator (DRI) of RACH PDU.As shown in Table 15, by DRI being mapped to a specific QPSK code element S _dridRI is embedded in the second controlled reference symbol, then, S _dricode element multiplies each other with pilot frequency code element p (k) before spatial manipulation.The second code element of the controlled benchmark of RACH can be expressed as:

$\underset{\&OverBar;}{x}\left(k\right)={\underset{\&OverBar;}{\overset{^}{K}}}_{\mathrm{ut}}\left(k\right)\&CenterDot;{\underset{\&OverBar;}{\overset{^}{v}}}_{\mathrm{ut},1}\left(k\right)\&CenterDot;s_{\mathrm{dri}}\&CenterDot;p\left(k\right),k\&Element;K^{\&prime;}---\left(65\right)$

As shown in formula (64) and (65), the only eigenvector of main eigenmodes just be used for the controlled benchmark of RACH.

The code element of the controlled benchmark that user terminal sends in the leader of RCH can be expressed as:

${\underset{\&OverBar;}{x}}_{\mathrm{up},\mathrm{sr},m}\left(k\right)={\underset{\&OverBar;}{\overset{^}{K}}}_{\mathrm{ut}}\left(k\right)\&CenterDot;{\underset{\&OverBar;}{\overset{^}{v}}}_{\mathrm{ut},m}\left(k\right)\&CenterDot;p\left(k\right),k\&Element;K^{\&prime;},---\left(66\right)$

Wherein x _{up, sr, m}(m) be the transmission vector of the subband k of broadband eigenmodes m; And

be broadband eigenmodes m subband k dominant vector ( m row).

The code element of the controlled benchmark that access point sends in the leader of RCH can be expressed as:

${\underset{\&OverBar;}{x}}_{\mathrm{dn},\mathrm{sr},m}\left(k\right)={\underset{\&OverBar;}{\overset{^}{K}}}_{\mathrm{ap}}\left(k\right)\&CenterDot;{\underset{\&OverBar;}{\overset{^}{u}}}_{\mathrm{ap},m}^{*}\left(k\right)p\left(k\right),k\&Element;K^{\&prime;},---\left(67\right)$

Wherein x _{dn, sr, m}(m) be the transmission vector of the subband k of broadband eigenmodes m; And

it is the correction matrix of the subband k of access point; And

it is the dominant vector of the subband k of broadband eigenmodes m.

Dominant vector to estimate through the downlink channel response of calibration the right eigenvector matrix m row, wherein ${\underset{\&OverBar;}{\overset{^}{U}}}_{\mathrm{ap}}\left(k\right)=\left[\begin{array}{cccc}{\underset{\&OverBar;}{\overset{^}{u}}}_{\mathrm{ap},1}\left(k\right)& {\underset{\&OverBar;}{\overset{^}{u}}}_{\mathrm{ap},2}\left(k\right)& {\underset{\&OverBar;}{\overset{^}{u}}}_{\mathrm{ap},3}\left(k\right)& {\underset{\&OverBar;}{\overset{^}{u}}}_{\mathrm{ap},4}\left(k\right)\end{array}\right]$

Controlled benchmark can send in every way.In one embodiment, one or more eigenvectors are used for the controlled benchmark of each tdd frame, and depend on the duration of controlled benchmark, and the latter is represented by the FCH/RCH leader type field in FCCH information element.Table 36 is listed for an exemplary design, the eigenmodes using for the RCH of various leader sizes and the leader of RCH.

Table 36

Shown in table 36, in the time that guide's sequence size is 4 or 8 OFDM code elements, for whole four eigenmodes in single tdd frame send controlled benchmark.User terminal is that the controlled benchmark that in the leader of RCH, n OFDM code element sends can be expressed as:

${\underset{\&OverBar;}{x}}_{\mathrm{up},\mathrm{sr},n}\left(k\right){\underset{\&OverBar;}{\overset{^}{K}}}_{\mathrm{ut}}\left(k\right)\&CenterDot;{\underset{\&OverBar;}{\overset{^}{v}}}_{\mathrm{ut},n\mathrm{mod}4}\left(k\right)\&CenterDot;p\left(k\right),k\&Element;K^{\&prime;},n=\{1,...,L\},---\left(68\right)$

Wherein L is leader size, and for type 2, L=4, for type 3, L=8.

Similarly, in the leader that access point is FCH, the controlled benchmark of n OFDM code element transmission can be expressed as:

${\underset{\&OverBar;}{x}}_{\mathrm{dn},\mathrm{sr},n}\left(k\right)={\underset{\&OverBar;}{\overset{^}{K}}}_{\mathrm{aap}}\left(k\right)\&CenterDot;{\underset{\&OverBar;}{\overset{^}{u}}}_{\mathrm{ap},n\mathrm{mod}4}^{*}\left(k\right)p\left(k\right),k\&Element;K^{\&prime;},n=\{1,...,L\}---\left(69\right)$

As shown in formula (68) and (69), circulate through four eigenmodes in each 4-code-element period by (the n mod 4) computing of dominant vector.This scheme can in the time that channel changes more fast, use and/or in the time obtaining good channels for correct system action need and estimate at the early application of a connection.

In another embodiment, for a broadband eigenmodes of each tdd frame sends controlled benchmark.For example, in four tdd frames, can circulate through the controlled benchmark of four broadband eigenmodes.For example, user terminal can be respectively first, second, third and the 4th tdd frame use dominant vector with the specific dominant vector using can be specified by 2 LSB of frame counter value in BCH message.This scheme can be used shorter leader part in PDU, but may require the time period of growing to obtain the good estimation of channel.

For above-mentioned two embodiment, can in transfer of data whole four eigenmodes used, send controlled benchmark, be less than four eigenmodes (for example due to untapped eigenmodes is very poor and abandon by water filling) even if used at present.Controlled benchmark at present do not use transmission in eigenmodes make to receive function determine when eigenmodes is improved to can be selected.

B. the controlled benchmark of wave beam control

For wave beam control model, the spatial manipulation of transmitting terminal is carried out with one group of standardization eigenvector of main broadband eigenmodes.The overall transfer function with standardization eigenvector be different from there is nonstandardized technique eigenvector overall transfer function ( ${\underset{\&OverBar;}{H}}_{\mathrm{cup}}\left(k\right){\underset{\&OverBar;}{\overset{^}{v}}}_{\mathrm{ut},1}\left(k\right)\&NotEqual;{\underset{\&OverBar;}{H}}_{\mathrm{cup}}\left(k\right){\underset{\&OverBar;}{\overset{~}{v}}}_{\mathrm{ut}}\left(k\right)$ )。Then, can be sent by transmitter with the controlled benchmark that one group of standardization eigenvector of whole subbands generates, and these subband induced matching filter vector that are used for as wave beam control model by receiver.

For up link, the controlled benchmark of wave beam control model can be expressed as:

${\underset{\&OverBar;}{\overset{~}{x}}}_{\mathrm{up},\mathrm{sr}}\left(k\right)={\underset{\&OverBar;}{\overset{^}{K}}}_{\mathrm{ut}}\left(k\right){\underset{\&OverBar;}{\overset{~}{v}}}_{\mathrm{ut}}\left(k\right)p\left(k\right),k\&Element;K.---\left(70\right)$

At access point place, the controlled benchmark of the receiving uplink of wave beam control model can be expressed as:

${\underset{\&OverBar;}{\overset{~}{r}}}_{\mathrm{up},\mathrm{sr}}\left(k\right)={\underset{\&OverBar;}{H}}_{\mathrm{up}}\left(k\right){\underset{\&OverBar;}{x}}_{\mathrm{up},\mathrm{sr}}\left(k\right)+{\underset{\&OverBar;}{n}}_{\mathrm{up}}\left(k\right),k\&Element;K---\left(71\right)$

$={\underset{\&OverBar;}{H}}_{\mathrm{up}}\left(k\right){\underset{\&OverBar;}{\overset{^}{K}}}_{\mathrm{ut}}\left(k\right){\underset{\&OverBar;}{\overset{~}{v}}}_{\mathrm{ut}}\left(k\right)p\left(k\right)+{\underset{\&OverBar;}{n}}_{\mathrm{up}}\left(k\right)$

$={\underset{\&OverBar;}{H}}_{\mathrm{cup}}\left(k\right){\underset{\&OverBar;}{\overset{~}{v}}}_{\mathrm{ut}}\left(k\right)p\left(k\right)+{\underset{\&OverBar;}{n}}_{\mathrm{up}}\left(k\right)$

For the ul transmissions for using wave beam control obtains matched filter row vector , the reception vector of controlled benchmark first with p ^*(k) multiply each other.So on the controlled reference symbol of multiple receptions to result integration with form estimation.So vectorial it is exactly the conjugate transpose of this estimation.

In the time being operated under wave beam control model, user terminal can send multiple code elements of controlled benchmark, for example, use standardization eigenvector one or more code elements, use the eigenvector of main broadband eigenmodes one or more code elements and may use one or more code elements of the eigenvector of other broadband eigenmodes.With the controlled reference symbol generating can be used for induced matching filter vector by access point with the controlled reference symbol generating can be used to obtain then be used for deriving the standardization eigenvector that on down link, wave beam control is used .With the eigenvector of other eigenmodes arrive the controlled reference symbol generating can be used for drawing by access point arrive and the singular value of these other eigenmodes.This information is then used for being defined as transfer of data usage space multiplexer mode or wave beam control model by access point.

For down link, user terminal can be estimated based on the downlink channel response through calibration for wave beam control model induced matching filter vector .Particularly, user terminal from singular value decomposition draw , and can derive standardization eigenvector .Then, user terminal can be with be multiplied by and draw mutually , then based on derive .Or controlled benchmark can use standardization eigenvector by access point send, this controlled benchmark can be processed to draw by user terminal in the above described manner

4. carrier pilot-up link

OFDM sub band structure described here comprises that index is four pilot subbands of-21 ,-7,7 and 21.In one embodiment, a carrier pilot is not to send in four pilot subbands of a leader part in whole OFDM code elements.Carrier pilot can be used for following the tracks of the phase place causing due to the drift of transmitter and receiver place oscillator by receiver to be changed.This may provide improved data demodulates performance.

Carrier pilot comprises four pilot frequency sequence P _c1(n), P _c2(n), P _c3and P (n) _c4(n), they are sent out in four pilot subbands.Pilot frequency sequence can be defined as:

P _c1(n)＝P _c2(n)＝P _c3(n)＝-P _c4(n)，n＝{1，2，...127}， (72)

Wherein n is the index of OFDM code-element period.

Pilot frequency sequence can define based on various data sequences.In one embodiment, pilot frequency sequence P _c1(n) based on multinomial G (x)=x ⁷+ x ⁴+ x generates, and wherein initial condition is set as entirely one, and output bit is mapped as signal value as follows: 1 -1 and 0 1.So, for n={1,2 ... 127}, pilot frequency sequence P _c1(n) can be expressed as:

P _c1(n)＝{1，1，1，1，-1，-1，-1，1，-1，-1，-1，-1，1，1，-1，1，-1，-1，1，1，-1，1，1，-1，1，1，1，1，1，1，-1，1，

1，1，-1，1，1，-1，-1，1，1，1，-1，1，-1，-1，-1，1，-1，1，-1，-1，1，-1，-1，1，1，1，1，1，-1，-1，1，1，

-1，-1，1，-1，1，-1，1，1，-1，-1，-1，1，1，-1，-1，-1，-1，1，-1，-1，1，-1，1，1，1，1，-1，1，-1，1，-1，1，

-1 ,-1 ,-1 ,-1 ,-1,1 ,-1,1,1 ,-1,1 ,-1,1,1,1 ,-1 ,-1,1 ,-1 ,-1 ,-1,1,1,1 ,-1 ,-1 ,-1 ,-1 ,-1 ,-1 ,-1}. pilot frequency sequence P _c1(n) value " 1 " in and " 1 " can be by a specific modulation to pilot frequency code elements.For example, by using BPSK, " 1 " is mapped as " 1+j ", and " 1 " is mapped as " (1+j) ".If had more than 127 OFDM code elements, repeat pilot frequency sequence, make for n > 127, P _c1(n)=P _c1(nmod127)

In one embodiment, be four pilot frequency sequences of each transmission channel replacement.Like this, on down link, be an OFDM code element replacement pilot frequency sequence of BCH message, be that an OFDM code element of FCCH message is reset again, and the OFDM code element sending for FCH is upper reset.In another embodiment, pilot frequency sequence is reset in the beginning of each tdd frame, and repeats as required.For this embodiment, pilot frequency sequence can be stopped during the leader part of BCH and RCH.

Under diversity mode, shown in table 29, four pilot frequency sequences are mapped as four subband/antennas pair.Particularly, P _c1(n) for subband-21 of antenna 1, P _c2(n) for subband-7 of antenna 2, P _c3(n) for the subband 7 of antenna 3, P _c4(n) for the subband 21 of antenna 4.Then each pilot frequency sequence is sent out on relevant subband and antenna.

Under space multiplexing mode, four pilot frequency sequences are sent out in the main eigenmodes of their corresponding subbands.The spatial manipulation of carrier pilot code element is similar to the processing of carrying out into modulated symbol, as mentioned above.Under wave beam control model, four pilot frequency sequences use wave beam to be controlled on their corresponding subbands and are sent out.The wave beam control of carrier pilot code element is also similar to the processing of carrying out into modulated symbol.

Above for MIMO wlan system has been described a specific pilot configuration.Also can be for this system is used other pilot configuration, this is within the scope of the invention.

IX. system operation

Figure 12 A illustrates a specific embodiments of the state diagram 1200 of user terminal operations.This state diagram comprises one of four states-initial (Init) state 1210, dormancy (Dormant) state 1220, access (Access) state 1230 and is connected (Connected) state 1240.Each state 1210,1220,1230 and 1240 is associated with multiple sub-states (not shown in Figure 12 A for simplicity).

In initial condition, user terminal capture systems frequency and timing, and obtain the upper system parameters sending of BCH.In initial condition, user terminal can be carried out following functions:

● determine-user terminal of system determines which carrier frequency to carry out capture systems with.

● frequency/timing acquisition-user terminal is caught beacon pilot frequency and is correspondingly regulated its frequency and timing.

● catch-user terminal processes BCH of parameter is with the system parameters obtaining with therefrom the access point of receiving downlink signal is associated.

Complete after the required function of initial condition, user terminal changes resting state into.

In resting state, whether user terminal periodically monitors the system parameters after renewal in BCH, the instruction to the paging sending on down link and broadcast, etc.Under this state, do not distribute any Radio Resource to user terminal.In resting state, user terminal can be carried out following functions:

● if register and ensured, user terminal just enters access state according to registration request.

● if the calibration of emittor/receiver ensured, user terminal just enters and accesses terminal according to calibration request.

● user terminal monitors whether BCH has the upper paging sending of couple FCH and the instruction of broadcast.

● if user terminal has the data that will send in up link, and it just enters access state according to resource request.

● user terminal is carried out such as upgrading system parameters and following the tracks of the such maintenance process of channel.

● user terminal can enter the operator scheme of time-division slot to save power supply, if this pattern is supported by user terminal.

If user terminal is all expected the Radio Resource from access point for any task, it just changes into and accesses terminal.For example, user terminal can change access state in response to the paging sending in BCH message or DST designator, for registration or request calibration, or asks special resource.

In access state, user terminal is in the process of connecting system.User terminal can send SMS message and/or request to FCH/RCH resource with RAHC.Operation on RACH is described in further detail as follows.If user terminal is access in a release, it just transforms back into resting state.If user terminal is assigned to the resource of down link and/or up link, it just changes connection status into.

In connection status, user terminal is assigned to FCH/RCH resource, although not necessary for each tdd frame.User terminal can use actively distributed resource or can in connection status, be idle (still keeping connecting).User terminal remains under connection status, until it be access in a release or it in a specific timeout period, do not have overtime after movable till, in this situation, it transforms back into resting state.

Under dormancy, access or connection status time, if if user terminal is closed power supply or connects to be lost, user terminal just transforms back into initial condition.

Figure 12 B illustrates a specific embodiments of the state diagram of connection status 1240.In this embodiment, connection status comprises three sub-states-set up sub-state 1260, open sub-state 1270 and idle sub-state 1280.User terminal enters the sub-state of setting up receive distribution on FCCH after.

Setting up in sub-state, user terminal is in the process of setting up connection, not yet swap data.Connect set up can comprise to access point, speed determine, the channel estimating of service negotiation etc.Set up after sub-state entering, user terminal arranges a timer in a specific time quantum.If timer expired before user terminal leaves this sub-state, it just changes resting state into.User terminal changes the sub-state of opening after setting up into completing to connect.

In the sub-state of unlatching, user terminal and access point be swap data in down link and/or up link.In the time opening in sub-state, user terminal monitors whether BCH has the instruction of system parameters and paging/broadcast.If be correctly decoded BCH message in the tdd frame of a specific quantity, user terminal transforms back into initial condition.

User terminal also monitors whether FCCH has channel allocation, speed control, RCH timing controlled and power control information.User terminal estimates with BCH beacon pilot frequency and FCH leader the SNR receiving, and determines the maximum rate that can reliably maintain on FCH.

The FCH of the user terminal of each tdd frame and RCH distribution are provided by the information element in the FCCH PDU sending in current (or may be previous) tdd frame.For arbitrary given tdd frame, for not distributing user terminal of the transfer of data on FCH and/or RCH.For not being wherein each tdd frame of data transmission scheduling user terminal, it does not receive FCH PDU on down link, and in up link, does not send.

For each tdd frame of scheduling user terminal wherein, the transfer of data in down link and/or up link is used FCCH to distribute speed, transmission mode and RCH timing slip (for up link) of in (being addressed to the FCCH information element of user terminal), representing to carry out.User terminal receives and sends to its FCH PDU, and it is carried out to demodulation code.User terminal also sends RCH PDU, and it comprises leader and RCH data rate indicator.The rate control information that user terminal comprises in distributing according to FCCH regulates the upper speed using of RCH.Ul transmissions applied power control if, the power control command that user comprises based on FCCH regulates its transmitted power.Exchanges data can happen suddenly, and in this situation, user terminal enters idle sub-state in the time not having data commutative.User terminal enters idle sub-state according to the instruction of access point.If access point is not distributed to user terminal FCH or RCH in the tdd frame of a specific quantity, user terminal transforms back into resting state and keeps its MAC ID.

In idle sub-state, up link and down link are all idle.In either direction, do not send data.But link maintains with controlled benchmark and control message.Under this sub-state, access point is at RCH and may on FCH, idle PDU periodically be distributed to user terminal (unnecessary while).Perhaps, user terminal can remain under connection status indefinitely, as long as access point periodically distributes idle PDU to maintain this link on FCH and RCH.

Under idle sub-state time, user terminal monitors BCH.If BCH message is not correctly decoded in the tdd frame of a specific quantity, user terminal just transforms back into initial condition.User terminal also monitors whether FCCH has channel allocation, speed control, RCH timing controlled and power control information.User terminal can also estimate to receive the maximum rate that SNR and definite FCH support.User terminal sends idle PDU RCH (in the time being assigned with) is upper, and if the RCH request bit that it has data to send just to arrange in idle PDU.If access point is not distributed to user terminal FCH or RCH in the tdd frame of a specific quantity, user terminal just transforms back into resting state, and keeps its MAC ID.

Entering after any one of three sub-states, overtime timer can be set as a particular value.If there is no activity in sub-state time, this timer countdown.During setting up, in activity or idle sub-state, if overtime timer expires, terminal can transform back into resting state, loses if connected, and terminal can transform back into initial condition.Under activity or idle sub-state time, be released if connected, terminal also can transform back into resting state.

Figure 12 A and 12B illustrate a specific embodiment of the state diagram that can be used for user terminal.Also can be for system definition has less, additional and/or different states and various other state diagrams of sub-state, this is within the scope of the invention.

X. access at random

In one embodiment, adopt a kind of random access scheme to make user terminal can access MIMO wlan system.In one embodiment, random access scheme is the Aloha scheme based on a time-division slot, and user terminal sends to can access this system in the random RACH time slot of selecting whereby.User terminal can send multiple transmission on RACH, until access licensed or reached maximum access attempts number of times.Can change the parameters of each RACH transmission to improve the probability of success, as described below.

Figure 13 has illustrated the timeline of RACH, and it is divided into RACH time slot.In each tdd frame and RACH time slot duration can with RACH number of time slot be configurable parameter.In each tdd frame, can use maximum 32 RACH time slots.Protection interval between the BCH PDU of the ending of a upper RACH time slot and next tdd frame starts is also configurable parameter.Three parameters of this of RACH can change along with the change of frame, and indicated by RACH length field, RACH time slot size field and the RACH protection interval field of BCH message.

In the time that user terminal is wished connecting system, it first treatments B CH to obtain relevant system parameters.Then, user terminal sends a RACH PDU on RACH.This RACH PDU comprises a RACH message, and it comprises access point is to process from the required information of the access request of user terminal.For example, RACH message comprises the MAC ID that user terminal is assigned to, and it makes access point energy identifying subscriber terminal.Registering MAC ID (being specific MAC ID value) can retain as unregistered user terminal.In this situation, the long ID of user terminal can be included in the load field of RACH message together with registration MAC ID.

As described below, RCH PDU can be sent out with one of four speed, as listed in table 15.Selected speed is embedded in the leader of RACH PDU (as shown in Figure 5 C).RACH PDU also has 1,2,4 or 8 OFDM code elements of variable-length (also as table 15 is listed), and this length represents in the message duration of RACH message field.

In order to send RACH PDU, first user terminal determines the RACH number of time slot (i.e. " available " RACH number of time slot) that can be used for transmission.This is determined based on making below: available RACH number of time slot in (1) current tdd frame, the duration of (2) each RACH time slot, (3) protection interval, and the length of (4) the RACH PDU that will send.RACH PDU can not extend beyond the ending of the RACH segmentation of tdd frame.Like this, if RACH PDU than a RACH time slot add protection interval long, this PDU can not one or more after a while can with RACH time slot on be sent out.Based on above-named factor, the RACH timeslot number that can be used for sending RACH PDU may be fewer than the number of available RACH time slot.RACH segmentation comprises a protection interval, and the latter can disturb with next BCH segmentation from the ul transmissions of user terminal for preventing, this is possible for the user terminal that does not compensate its round-trip delay.

Then, user terminal select randomly can with one of RACH time slot send RACH PDU.Then, user terminal starts to send RACH PDU from selected RACH time slot.If user terminal is known the round-trip delay of access point, it can be by correspondingly regulating its timing to make up this delay.

In the time that access point receives a RACH PDU, it checks this message with the CRC that reception RACH message comprises.If CRC failure, access point just abandons this RACH message.If CRC passes through, access point just arranges the RACH acknowledgement bit on BCH in follow-up tdd frame, and in 2 tdd frames, on FCCH, sends a RACH confirmation.Acknowledgement bit is set on BCH and sends between confirmation and may have delay on FCCH, it is for making up dispatch delay etc.For example, if access point receives message on RACH, it can arrange acknowledgement bit on BCH, and on FCCH, has delayed response.Acknowledgement bit stops user terminal to carry out retry, and makes unsuccessful user terminal retry fast, except within the busy RACH cycle.

If user terminal is being carried out registration, it just uses registration MAC ID (for example 0x0001).Access point responds by send a MAC ID assignment messages on FCH.All other RACH transport-types comprise the user terminal MAC ID that system is distributed.The MAC ID that access point is distributed to user terminal by use sends confirmation on FCCH, thereby has clearly confirmed all RACH message correctly receiving.

After user terminal sends RACH PDU, it monitors that BCH and FCCH are to determine whether its RACH PDU has been access in a reception and has processed.User terminal monitors that BCH is to determine whether to be provided with the RACH acknowledgement bit in BCH message.If this bit is established, this confirmation that shows this and/or other user terminal sends on FCCH, so user terminal is further processed FCCH to obtain IE type 3 information elements that comprise confirmation.Otherwise if RACH acknowledgement bit is not established, user terminal just continues monitor BCH or continue its access procedure on RACH.

FCCH IE type 3 is for transmitting the quick confirmation to successful access attempts.Each confirmation element comprises and the MAC ID being associated for its user terminal that sends confirmation.But it is received unconnected with the distribution of FCH/RCH resource to confirm to be fast used for its access request of informing user terminal.On the contrary, the confirmation based on distributing distributes and is associated with a FCH/RCH.Confirm fast if user terminal receives one on FCCH, it just changes resting state into.If the confirmation of user terminal reception one based on distributing, it just obtains the schedule information sending together with this confirmation, and brings into use the FCH/RCH distributing in current tdd frame.(

If user terminal receives a confirmation after sending RACH PDU in the tdd frame of a specific quantity on FCCH, it just continues the access procedure on RACH.In this situation, user terminal can suppose that access point does not correctly receive RACH PDU.User terminal maintains a counter access number of attempt is counted.This counter is initialized as zero at access attempts for the first time, then increases one for each access request subsequently.If Counter Value reaches maximum attempts, user terminal just stops access procedure.

For each follow-up access attempts, first user terminal determines the parameters of this access attempts, comprise that (1) is sending the time quantum that will wait for before RACH PDU, (2) the RACH time slot using for RACH PDU transmission, and the speed of (3) RACH PDU.In order to determine the time quantum that will wait for, first user terminal determines the maximum time amount that access attempts will be waited for next time, and this is called contention window (CW).In one embodiment, may to increase for each access attempts (be CW=2 to contention window (providing taking tdd frame as unit) index ^{access_attempt}).Contention window also can for example, be determined based on other function of some of access attempts number of times (linear function).Then the random time quantum of selecting next access attempts to wait between zero-sum CW.User terminal can be waited for this time quantum before sending RACH PDU for next access attempts.

For next access attempts, if be not that a upper access attempts uses minimum speed limit, user terminal reduces the speed of RACH PDU.The initial rate of the first access attempts can be selected by the reception SNR based on the upper pilot tone sending of BCH.Access point is failed correctly to receive RACH PDU and may be caused and fail to receive the confirmation.Like this, in next access attempts, the speed of RACH PDU is lowered, to improve the correct probability receiving of access point.

Waiting for that after this random stand-by period of selecting, user terminal is selected the transmission of a RACH time slot for RACH PDU again at random.The selection of the RACH time slot of this access attempts can be carried out with the similar fashion of above-mentioned the first access attempts, except the RACH parameter (being RACH timeslot number, time slot duration and protection interval) of (transmitting in BCH message) current tdd frame is used together with current RACH PDU length.Then RACH PDU is sent out in the random RACH time slot of selecting.

Above-mentioned access procedure continues until there is following any point: (1) user terminal receives a confirmation from access point, or (2) have reached the maximum number of attempt allowing.For each access attempts, can be chosen in as described above and send time quantum, the RACH PDU that before RACH PDU, will wait for and transmit the RACH time slot that will use and the speed of RACH PDU.If received the confirmation, user terminal is with regard to work indicated in confirmation (be that it waits in resting state in the time receiving quick confirmation, or use FCH/RCH to start in the time of the confirmation receiving based on distributing).If reached the maximum access attempts number of times allowing, user terminal just transforms back into initial condition.

XI. speed, power and timing controlled

Down link on access point scheduled FCH and RCH and ul transmissions, and further control the speed of all active user terminals.In addition, access point regulates the transmitted power of specific activities user terminal in up link.Can maintain various control loops comes for each active user terminals regulations speed, transmitted power and timing.

1. fixing and variable rate services

Access point can be supported the service of the fixing and variable bit rate on FCH and RCH.Fixed rate service can be used for voice, video etc.Variable rate services can be used for grouped data (for example web browsing).

For the fixed rate service on FCH/RCH, fixed rate is for whole connection.The transmission of best achievement is for FCH and RCH (not retransmitting).Access point is dispatched the FCH/RCH PDU of constant number in each fixed time interval, to meet the Qos requirement of service.According to postponing requirement, access point may be dispatched a FCH/RCH PDU without each tdd frame.For fixed rate service, on RCH instead of FCH, realize power control.

For the variable rate services on FCH/RCH, the speed that FCH/RCH uses can change along with channel condition.For example, for some synchronous service (video, audio frequency), qos requirement can be utilized minimum-rate constraints.For these services, the scheduler at access point place regulates FCH/RCH to distribute, thereby constant rate of speed can be provided.For example, for asynchronous data service (web-browsing, file transfer etc.), optimum efficiency transmission has re-transmission option.For these services, speed be channel condition the maximum that can reliably bear.The scheduling of FCH/RCH PDU to user terminal is generally the function of their qos requirement.In the time not having data to send, on FCH/RCH, send idle PDU to maintain link on downlink/uplink.For variable rate services, on FCH instead of RCH, realize the control of closed-loop power.

2. speed control

Speed control can be used for the variable rate services of FCH and the upper work of RCH, to make the speed of FCH/RCH be suitable for the channel condition changing.The speed that FCH and RCH use can be controlled independently.In addition,, in space multiplexing mode, the speed of each broadband eigenmodes of each dedicated transmission channel can independently be controlled.The feedback that speed control is provided based on each active user terminals by access point is carried out.Scheduler schedules transfer of data in access point, and the rate-allocation of definite active user terminals.

The maximum rate that can support on arbitrary link is all following function: the channel response matrix of (1) total data subchannel, (2) the viewed noise level of receiver, (3) quality of channel estimating, and may other factors.For TDD system, channel can be considered to be reciprocal (carrying out calibration to make up after any difference at access point and user terminal place) for down link and up link.But this reciprocal channel does not also mean that noise floor is identical with user terminal place at access point.Therefore,, for given user terminal, the speed on FCH and RCH can be controlled independently.

The control of closed-loop speed can be used for the transfer of data on one or more space channels.The control of closed-loop speed can realize with one or more loops.Inner ring road is estimated channel condition and is that transfer of data each space channel used is selected a suitable speed.Channel estimating and speed are selected to carry out as described above.Outer ring can be used for estimating the quality of the transfer of data receiving on each space channel, and regulates the operation of inner ring road.Data transmission quality can quantize with packet error rate (PER), decoder metric etc. or their combination.For example, outer ring can regulate the SNR skew of each space channel to be this space channel realize target PER.Space channel detects excessive packet error if, and it is that a space channel selects one compared with low rate that outer ring also can be indicated inner ring road.

Downlink rate control

Each active user terminals can the MIMO pilot tone based on sending on BCH in each tdd frame be carried out estimating down-ward link channel.Access point also can send a controlled benchmark in the FCH PDU that sends to specific user terminal.By the MIMO pilot tone on use BCH and/or the controlled benchmark on FCH, user terminal can estimate to receive the maximum rate that can support on SNR and definite FCH.If user terminal is operated under space multiplexing mode, just can determine maximum rate for each broadband eigenmodes.Each user terminal can be in the FCH of RCH PDU rate indicator field beams back to access point the maximum rate (for diversity mode) that maximum rate (for space multiplexing mode) that each broadband eigenmodes supports, maximum rate (for wave beam control model) that main broadband eigenmodes is supported or mimo channel are supported.These speed can be mapped as and receive SNR, and the latter is then used for carrying out above-mentioned the injecting process.For example, or user terminal can be beamed back sufficient information (receiving SNR) to make access point can determine the maximum rate that down link is supported.

That feedback based on from user terminal is made for using diversity, wave beam control or space multiplexing mode definite.Along with the separation between dominant vector improves, the number of the broadband eigenmodes of selecting also can increase.

Figure 14 A has illustrated the process for the speed of user terminal control downlink transmission.One BCH PDU sends in the first segmentation of each tdd frame, and comprises beacon and the MIMO pilot tone that can be used for estimation and be followed the tracks of this channel by user terminal.Controlled benchmark also can be sent out in the leader of the FCH PDU sending to user terminal.User terminal is estimated this channel based on MIMO and/or controlled benchmark, and the maximum rate that can support of definite down link.If under space multiplexing mode, being each broadband eigenmodes, user job supports a speed.Then in the FCH rate indicator field of the RCH PDU that, user terminal sends to access point at it, send the rate indicator of FCH.

Scheduler can be dispatched the downlink transmission in follow-up tdd frame for the maximum rate of each active user terminals support with down link.In the information element that the speed of user terminal and other channel allocation information send on FCCH, reflect.The speed of distributing to a user terminal can affect the scheduling of other user terminal.User determines that the minimum delay between speed and use thereof is about single tdd frame.

By using Gram-Schmidt sequencer procedure, access point can directly determine from RCH leader the maximum rate that FCH supports exactly.So this can simplify speed control greatly.

Uplink rate control

Each user terminal is sending a controlled benchmark on RACH during system access, and after FCH/RCH resource, on RCH, sends controlled benchmark being assigned to.Access point can the controlled benchmark based on RCH be that each broadband eigenmodes estimates to receive SNR, and determines the maximum rate that each broadband eigenmodes is supported.First the channel estimating that, access point may not have is to allow the maximum rate place supporting in each broadband eigenmodes or near the reliable operation carrying out it.In order to improve reliability, the initial rate of the upper use of FCH/RCH can be significantly less than the maximum speed of supporting.Access point can be on multiple tdd frames to controlled benchmark integration to obtain improved channel estimating.Along with the raising of channel estimating, speed also can be enhanced.

Figure 14 B has illustrated the process of the speed that is used to user terminal control ul transmissions.In the time being uplink transmission scheduling, user terminal sends a RCH PDU, and it comprises that access point is used for determining the benchmark of the maximum rate in up link.Then, scheduler can be dispatched the uplink data transmission in follow-up tdd frame for the maximum rate of each active user terminals support by up link.The speed of user terminal and other channel allocation information are reflected in the upper information element sending of FCCH.Access point determines that the minimum delay between speed and use thereof is about single tdd frame.

3. power control

For fixed rate service, power control can be used for the ul transmissions (but not speed control) on RCH.For fixed rate service, speed is consulted in the time of call setup, and during connecting, keeps fixing.Some fixed rate services may require to be associated with limited mobility.But in one embodiment, for up link has realized power control with the interference between antagonism user terminal, but down link is not used to power control.

One power control mechanism is used for controlling the up-link transmit power of each active user terminals, and the SNR that access point place is received is maintained at a rank that can realize desired service quality.This rank is commonly referred to target and receives SNR, working point or set point.For mobile user terminal, propagation loss probably changes along with moving of user terminal.Power control mechanism is followed the tracks of the variation in channel to remain near set point receiving SNR.

Power control mechanism can be with two power control loop road realization-inner ring roads and outer ring.The transmitted power of inner loop adjustment user terminal, is maintained near set point the reception SNR at access point place.Outer ring regulates set point to realize other performance of a specific order, and performance for example, measures quantification by specific FER (Floating Error Rate) (FER) (1%FER), packet error rate (PER), BLER (block error rate) (BLER), message error rate (MER) or some.

Figure 15 has illustrated the operation of the internal power control of user terminal.Be assigned to after FCH/RCH at user terminal, access point is estimated the reception SNR on RCH and it is compared with set point.The initial power that user terminal will use can determine in the time of call setup, and generally near its maximum transmit power level.For each frame period, exceed a specific positive surplus δ if receive SNR, access point just can reduce a specified quantitative (for example 1dB) by its transmitted power by indicating user terminal in the FCCH information element that sends to this user terminal.On the contrary, if receive SNR than the low surplus δ of threshold value, access point just can improve described specified quantitative by its transmitted power by indicating user terminal.If receive SNR in acceptable set point restriction, access point just can not ask the transmitted power of user terminal to change.Up-link transmit power is given initial transmission power level and adds all power adjustments sums that receive from access point.

The initial setting point of access point place use is set to realize other performance of a specific order.By outer ring, the FER based on RCH or PER regulate this set point.For example, if there is not frame error/packet error on a special time period, set point can reduce the first amount (for example 0.1dB).For example, if owing to occurring that one or more frame error/packet errors exceed mean F ER, set point can improve the second amount (1dB).It is specific that set point, hysteresis margin and outer ring operate the power control design using for system.

4. timing controlled

Timing controlled is preferably used in the frame structure based on TDD, and wherein down link and up link are shared identical frequency band in the mode of time division duplex.User terminal can spread in system, and is therefore associated from the different propagation delays to access point.In order to make the efficiency maximum in up link, can regulate timing from the ul transmissions on RCH and the RACH of each user terminal to make up its propagation delay.So this can ensure to arrive access point place from the ul transmissions of different user terminals in a special time window, and can be not interfering with each other in up link, or like this for downlink transmission.

Figure 16 has illustrated the process of the uplink timing for regulating user terminal.First, user terminal sends a RACH PDU so that can connecting system in up link.Access point is derived the initial estimation of the round-trip delay (TDD) being associated with user terminal.Round-trip delay can be based on following estimation: (1) access point is used for determining the sliding correlation detector of transmission starting point, and the time slot ID that comprises of the RACH PDU that sends of (2) user terminal.Then, access point is estimated as user terminal based on Initial R TD and calculates an initial timing lead.Initial timing lead is sent to user terminal at it before the transmission on RCH.Initial timing lead can be sent out in a message, in a field of FCCH information element, be sent out on FCH, or is sent out by some other means.

User terminal receives initial timing lead from access point, then in all subsequent uplink transmission on RCH and RACH, uses this Timing Advance.If user terminal is assigned to FCH/RCH resource, the order that its Timing Advance just can regulate the access point in field to send by the RCH timing of FCCH information element regulates.So user terminal can regulate its ul transmissions on RCH by the Timing Advance based on current, current Timing Advance equals initial timing lead and adds that access point sends to whole timings adjustings of user terminal.

Each part of MIMO wlan system described herein and various technology can be carried out time slot by various means.For example, the processing at access point and user terminal place can realize with hardware, software or their combination.For hardware is realized, processing can realize in following components and parts: one or more application-specific integrated circuit (ASIC)s (ASIC), digital signal processor (DSP), digital signal processing appts (DSPD), programmable logic device (PLD), field programmable gate array (FPGA), processor, controller, microcontroller, microprocessor, other is designed to carry out the electronic unit of function described here or their combination.

For software is realized, processing can for example, realize by the module (process, function etc.) of carrying out function described here.Software code for example can be stored in, in memory cell (memory 732 or 782 in Fig. 7), and for example, is carried out by processor (controller 730 or 780).Memory cell can be in processor or processor realize outward, in a rear situation, it is by being coupled on various means well known in the art and processor communication.

Here the title comprising facilitates index, and helps the specific chapters and sections in location.These titles are not the scopes in order to limit its lower described concept, and these concepts can be applied in other chapters and sections of entire description.

The description of above preferred embodiment makes those skilled in the art can manufacture or use the present invention.The various amendments of these embodiment are apparent for a person skilled in the art, and the General Principle of definition can be applied in other embodiment and do not deviate from the spirit or scope of the present invention here.Therefore, the present invention is not limited to shown here embodiment, and will meet the most wide in range scope consistent with the principle disclosing and novel feature here.

Claims (21)

1. a method for access wireless multiple access multiple-input and multiple-output (MIMO) communication system, comprising:

On down link via the first transmission channel receiving system information;

In up link, send an access request via the second transmission channel, the system information of wherein said access request based on received is sent out;

Monitor whether the 3rd transmission channel on down link sends the confirmation of access request to some extent; And

If do not receive described confirmation in predetermined time section, repeat described reception, transmission and supervision step.

2. the method for claim 1, is characterized in that, also comprises:

Monitor the acknowledgement bit in described the first transmission channel,

Wherein monitor that the 3rd transmission channel comprises:

If be provided with described acknowledgement bit, process described the 3rd transmission channel for described confirmation.

3. the method for claim 1, is characterized in that, has sent multiple access requests.

4. method as claimed in claim 3, is characterized in that, sends described multiple access requests with the speed successively reducing.

5. method as claimed in claim 3, characterized by further comprising:

Send next access request in described multiple access requests before, wait for a pseudorandom time period.

6. method as claimed in claim 3, characterized by further comprising:

On described the second transmission channel, send a controlled pilot tone together with described access request, described controlled pilot tone is sent out at least one eigenmodes of the mimo channel of up link.

7. the method for claim 1, is characterized in that, described system information shows wherein to allow to send the time interval of access request, and wherein said access request is sent out within the described time interval.

8. the method for claim 1, is characterized in that, described system information shows wherein to allow the time slot of the specific quantity that sends access request, and wherein said access request has identified the particular time-slot that wherein sends this access request.

9. method as claimed in claim 8, is characterized in that, described time slot has can be by duration time of system configuration.

10. a kind of device in wireless multiple access multiple-input and multiple-output (MIMO) communication system, comprising:

On down link via the reception data processor of the first transmission channel receiving system information;

For the treatment of the transmission data processor of the access request sending via the second transmission channel in up link, the system information of wherein said access request based on received is sent out;

For monitoring whether the 3rd transmission channel on down link sends the controller of the confirmation of access request to some extent, and

If wherein do not receive within a predetermined period of time described confirmation, described reception data processor is for receiving the system information after renewal, and described transmission data processor is for the treatment of another access request, and described controller monitors described the 3rd transmission channel.

11. devices as claimed in claim 10, it is characterized in that, described controller is for monitoring the acknowledgement bit of described the first transmission channel, and in the time being provided with described acknowledgement bit, to indicate described reception data processor be that described the 3rd transmission channel is processed in described confirmation.

12. devices as claimed in claim 10, is characterized in that, have sent multiple access requests.

13. devices as claimed in claim 12, is characterized in that, send described multiple access requests with the speed successively reducing.

14. devices as claimed in claim 12, is characterized in that, described controller for waiting for a pseudorandom time period before described multiple access requests start to send next access request.

15. devices as claimed in claim 12, characterized by further comprising:

Send spatial processor, for send a controlled pilot tone together with described access request on described the second transmission channel, described controlled pilot tone is sent out at least one eigenmodes of the mimo channel of up link.

A kind of device in 16. wireless multiple access multiple-input and multiple-output (MIMO) communication systems, comprising:

For the device via the first transmission channel receiving system information on down link;

For send the device of access request via the second transmission channel in up link, the system information of wherein said access request based on received is sent out;

For monitoring whether the 3rd transmission channel on down link sends the device of the confirmation of access request to some extent; And

If described confirmation does not receive within a predetermined period of time, repeat the device of described reception, transmission and supervisory work.

17. devices as claimed in claim 16, is characterized in that, describedly comprise for the device that monitors the 3rd transmission channel:

Be used for the device of the acknowledgement bit that monitors described the first transmission channel, and

If be provided with described acknowledgement bit, it is the device that described the 3rd transmission channel is processed in described confirmation.

18. devices as claimed in claim 16, is characterized in that, have sent multiple access requests.

19. devices as claimed in claim 18, is characterized in that, send described multiple access requests with the speed successively reducing.

20. devices as claimed in claim 18, characterized by further comprising:

Send next access request in described multiple access requests before, wait for a pseudorandom time period.

21. devices as claimed in claim 18, characterized by further comprising:

For send the device of a controlled pilot tone together with described access request on described the second transmission channel, described controlled pilot tone is sent out at least one eigenmodes of the mimo channel of up link.