CN101632253A - Multiplexing of feedback channels in a wireless communication system - Google Patents

Abstract

Techniques for sending signaling in a wireless communication system are described. Multiple feedback channels may be multiplexed such that they can share time frequency resources. Each feedback channel may be allocated a different subset of subcarriers in each of at least one tile. In one design, a subscriber station may determine time frequency resources including first and second portions of time frequency resources for first and second feedback channels, respectively. The subscriber station may send vectors of modulation symbols of a first length on the first feedback channel and/or vectors of modulation symbols of a second length on the second feedback channel. A base station may receive the first and second feedback channels and may perform detection on vectors of received symbols for each feedback channel to recover the signaling sent on that feedback channel.

Description

Multiplexing of feedback channels in a wireless communication system

The application claims priority OF U.S. provisional application No. 60/894,378, assigned to the assignee OF the present application, entitled "efficientfiltering OF PRIMARY AND SECONDARY FAST feedback channels IN A WIRELESS COMMUNICATION SYSTEM", filed on 12.3.2007. This application is incorporated herein by reference.

Technical Field

The present disclosure relates to communications. And more specifically to techniques for transmitting signaling in a wireless communication system.

Background

Wireless communication systems are widely deployed to provide various communication contents such as: voice, video, packet data, messaging, broadcast, etc. These wireless systems may be multiple-access systems capable of supporting multiple users by sharing the available system resources. Examples of these multiple access systems include: code Division Multiple Access (CDMA) systems, Time Division Multiple Access (TDMA) systems, Frequency Division Multiple Access (FDMA) systems, Orthogonal Frequency Division Multiple Access (OFDMA) systems, and single carrier FDMA (SC-FDMA) systems.

A wireless communication system may include any number of base stations capable of supporting communication for any number of subscriber stations on the downlink and uplink. The downlink (or forward link) refers to the communication link from the base stations to the subscriber stations. The uplink (or reverse link) refers to the communication link from the subscriber stations to the base stations. The system may use various feedback channels to send signaling. Signaling is useful, but the signaling amounts to overhead in the system.

Accordingly, there is a need in the art for techniques to efficiently transmit signaling in a wireless communication system.

Disclosure of Invention

Techniques for efficiently sending signaling in a wireless communication system are described herein. In an aspect, multiple feedback channels may be multiplexed, enabling the feedback channels to share time-frequency resources. The time-frequency resource may include at least one tile (tile), where each tile includes at least one subcarrier in each of at least one symbol period. Each feedback channel may be assigned a different subset of the subcarriers in each tile.

In one design, a subscriber station may determine (e.g., via an allocation message) time frequency resources comprising a first portion of time frequency resources for a first feedback channel and a second portion of time frequency resources for a second feedback channel. The first portion of time frequency resources and the second portion of time frequency resources may include disjoint first and second subsets of subcarriers in each of the at least one tile, respectively. The subscriber station may send signaling on the first feedback channel using the first portion of time frequency resources and/or on the second feedback channel using the second portion of time frequency resources. The subscriber station may transmit a vector of modulation symbols of a first length for a first feedback channel on a first portion of time frequency resources. Alternatively or additionally, the subscriber station may transmit a vector of modulation symbols of a second length for a second feedback channel on a second portion of time frequency resources.

In one design, the base station may receive first and second feedback channels on first and second portions of time frequency resources, respectively. The base station may obtain a vector of received symbols of a first length for a first feedback channel and may obtain a vector of received symbols of a second length for a second feedback channel. The base station may detect for a vector of received symbols for the first feedback channel based on a first set of vectors of modulation symbols available for the first feedback channel. The base station may also detect for a vector of received symbols for the second feedback channel based on a second set of vectors of modulation symbols available for the second feedback channel.

Various aspects and features of the disclosure are described in more detail below.

Drawings

Fig. 1 illustrates a wireless communication system.

Fig. 2 illustrates a subcarrier structure for Partially Using Subcarriers (PUSC).

Fig. 3 shows a sheet structure of PUSC.

Fig. 4A shows a tile structure for the primary fast feedback channel.

Fig. 4B shows a tile structure for a secondary fast feedback channel.

Fig. 5 shows a tile structure for multiplexing a primary fast feedback channel and a secondary fast feedback channel.

Fig. 6 shows a QPSK signal constellation.

Fig. 7 shows a procedure for signaling.

Fig. 8 shows an apparatus for sending signaling.

Fig. 9 shows a process for receiving signaling.

Fig. 10 illustrates an apparatus for receiving signaling.

Fig. 11 shows a block diagram of two subscriber stations and a base station.

Detailed Description

The techniques described herein may be used for various wireless communication systems, such as: CDMA, TDMA, FDMA, OFDMA and SC-FDMA systems. The techniques may also be used for systems supporting Spatial Division Multiple Access (SDMA), Multiple Input Multiple Output (MIMO), and so on. The terms "system" and "network" are often used interchangeably. OFDMA systems may implement methods such as Ultra Mobile Broadband (UMB), evolved universal terrestrial radio access (E-UTRA), IEEE 802.20, IEEE802.16 (also known as WiMAX), IEEE 802.11 (also known as Wi-Fi), Flash-And so on. These radio technologies and standards are known in the art.

For clarity, various aspects of the techniques are described below for WiMAX, which is included in IEEE802.16 under the designation "Part 16: air Interface for Fixed and Mobile broadband Wireless Access Systems, date 10/1/2004, and IEEE802.16e, entitled "Part 16: air Interface for Fixed and Mobile broadband wireless Access Systems; amino 2: physical and Medium Access controls for Combined Fixed and Mobile Operation in qualified Bands "on a date of 2006, month 2 and day 28. These documents are publicly available. The present technique may also be used with IEEE802.16m, which is a new air interface being developed for WiMAX.

The techniques described herein may be used to send signaling in the uplink and downlink. For clarity, various aspects of the present techniques are described below for signaling on the uplink.

Fig. 1 shows a wireless communication system 100 having a plurality of Base Stations (BSs) 110 and a plurality of Subscriber Stations (SSs) 120. A base station is a station that supports communication for a subscriber station and may perform functions such as connection, management, and control of the subscriber station. A base station may also be referred to as a node B, an evolved node B, an access point, etc. A system controller 130 may connect to base stations 110 and provide coordination and control for these base stations.

Subscriber stations 120 may be dispersed throughout the system and each subscriber station may be fixed or mobile. A subscriber station is a device that can communicate with a base station. A subscriber station may also be called a mobile station, terminal, access terminal, user equipment, subscriber unit, station, etc. The subscriber station may be a cellular telephone, a Personal Digital Assistant (PDA), a wireless device, a wireless modem, a handheld device, a laptop computer, a cordless telephone, or the like.

IEEE802.16 uses Orthogonal Frequency Division Multiplexing (OFDM) for the downlink and uplink. OFDM divides the system bandwidth into multiple (N)_FFTMultiple) orthogonal subcarriers, which may also be referred to as tones (tones), bins (bins), etc. Each subcarrier may be modulated with data or pilot. The number of subcarriers may depend on the system bandwidth and the spacing between adjacent subcarriers. E.g. N_FFTMay be equal to 128, 256, 512, 1024 or 2048. Total N_FFTOnly a subset of the subcarriers may be used for data and pilot transmission, and the remaining subcarriers may be used as guard subcarriers, thereby resulting in a system spectral mask (mask) requirement. In the following description, data subcarriers are subcarriers used for data, and pilot subcarriers are subcarriers used for pilot. An OFDM symbol may be transmitted in each OFDM symbol period (or just in the symbol period). Each OFDM symbol may include data subcarriers used to transmit data, pilot subcarriers used to transmit pilot, and guard subcarriers not used for data or pilot.

Fig. 2 shows a subcarrier structure 200 for PUSC for uplink in IEEE 802.16. The available subcarriers may be divided into N_tilesAnd (3) slicing. Each tile may include four subcarriers in each of the three OFDM symbols and may include a total of 12 subcarriers.

Fig. 3 shows a tile structure 300 for uplink transmission of data and pilot in IEEE 802.16. In structure 300, a tile includes four pilot subcarriers located at the four corners of the tile and eight data subcarriers located at the eight remaining locations in the tile. A data modulation symbol may be sent on each data subcarrier and a pilot modulation symbol may be sent on each pilot subcarrier.

A fast feedback channel may be defined and used to carry various signaling, such as: channel Quality Information (CQI), Acknowledgements (ACK), MIMO mode, MIMO coefficients, etc. The fast feedback channel may be allocated uplink time slots, also referred to as fast feedback time slots. As shown in fig. 2, an uplink slot may include six tiles, labeled tile (0) through tile (5). In general, the six tiles of one uplink slot may be adjacent to each other (as shown in fig. 2) or dispersed throughout the system bandwidth (not shown in fig. 2).

Fig. 4A shows a tile structure 400 that may be used for the primary fast feedback channel. As shown in fig. 4A, eight vectors of modulation symbols may be transmitted on eight subcarriers of a tile. The eight subcarriers here correspond to the data subcarriers in the tile shown in fig. 3. Assigning an index M to eight modulation symbols transmitted in a tile_n，8m+kWhere k is greater than or equal to 0 and less than or equal to 7, n is the index of the fast feedback channel, m is the index of the tile, and k is the index of the modulation symbols transmitted in the tile. Thus, M_n，8m+kIs the modulation symbol index of the kth modulation symbol in the mth tile of the nth fast feedback channel. No symbols are sent on the four subcarriers at the four corners of the tile, which correspond to the four pilot subcarriers in fig. 3.

Fig. 4B shows a tile structure 410 that may be used for a secondary fast feedback channel. As shown in fig. 4B, four vectors of modulation symbols may be transmitted on the four subcarriers of a tile. These four subcarriers correspond to the pilot subcarriers in the tile shown in fig. 3. Assigning an index M to four modulation symbols transmitted in a tile_n，4m+kWherein 0. ltoreq. k.ltoreq.3, n, m and k being as defined above. No symbols are sent on the remaining eight subcarriers in the tile, which correspond to the eight data subcarriers in fig. 3.

Fig. 5 shows a design of a tile structure 500 that may be used to multiplex primary and secondary fast feedback channels on the same tile to share time-frequency resources. Time-frequency resources may also be referred to as transmission resources, signaling resources, radio resources, and so on. In this design, the primary fast feedback channel is allocated eight subcarriers in the tile, which correspond to the eight data subcarriers in fig. 3. The secondary fast feedback channel is allocated four subcarriers at the four corners of the tile, which correspond to the four pilot subcarriers in fig. 3. Thus, the primary and secondary fast feedback channels are allocated two disjoint subsets of subcarriers in the same tile and both channels can be transmitted simultaneously without interfering with each other.

Fig. 5 shows one design for multiplexing the primary and secondary fast feedback channels on the same chip. In general, each fast feedback channel may be allocated any number of subcarriers and any one subcarrier in a tile. It is also possible to multiplex more than two fast feedback channels on the same chip. Each fast feedback channel may be allocated a different subset of the subcarriers in a tile. The fast feedback channels multiplexed on the same tile may be allocated the same or different number of subcarriers.

In one design, a single subscriber station may send signaling on both the primary and secondary fast feedback channels on the same chip. This allows the subscriber station to send more signaling on the time-frequency resources allocated to these fast feedback channels.

In another design, two subscriber stations may share the same tile. One subscriber station may send signaling on a primary fast feedback channel on one portion of the tile and another subscriber station may send signaling on a secondary fast feedback channel on another portion of the tile. This multiplexing allows two subscriber stations to share and more fully utilize the time-frequency resources.

The primary and secondary fast feedback channels may be transmitted on one uplink time slot, which may include six tiles. As shown in fig. 5, each tile may include eight subcarriers of the primary fast feedback channel and four subcarriers of the secondary fast feedback channel. In each tile, one vector with eight modulation symbols may be sent on eight subcarriers of the primary fast feedback channel and one vector with four modulation symbols may be sent on four subcarriers of the secondary fast feedback channel. Each modulation symbol may be transmitted on a different subcarrier.

For the primary fast feedback channel, eight orthogonal vectors may be formedv ₀Tov ₇. Each vector may include eight modulation symbols and may be represented as:

v _i＝[P_i，0 P_i，1 P_i，2 P_i，3 P_i，4 P_i，5 P_i，6 P_i，7]^Twhere i ═ 0., 7 formula (1)

Wherein, P_i，kIs an 8 element vectorv _iThe k modulation symbol in (a), and

“^T"represents transpose.

These eight vectorsv ₀Tov ₇Are mutually orthogonal, so:

<math> <mrow> <mo>|</mo> <mo>|</mo> <msubsup> <munder> <mi>v</mi> <mo>&OverBar;</mo> </munder> <mi>i</mi> <mi>H</mi> </msubsup> <msub> <munder> <mi>v</mi> <mo>&OverBar;</mo> </munder> <mi>l</mi> </msub> <mo>|</mo> <mo>|</mo> <mo>=</mo> <mn>0</mn> <mo>,</mo> </mrow> </math> wherein i is more than or equal to 0 and less than or equal to 7, l is more than or equal to 0 and less than or equal to 7, and i is not equal to l formula (2)

Wherein "^H"represents a conjugate transpose.

For the secondary fast feedback channel, four orthogonal vectors may be formedw ₀Tow ₃. Each vector may include four modulation symbols and may include four modulation symbolsExpressed as:

w _j＝[P_j，0 P_j，1 P_j，2 P_j，3]^Twhere j is 0.., 3 formula (3)

Wherein, P_j，kIs a 4-element vectorw _jThe k-th modulation symbol in (b).

These four vectorsw ₀Tow ₃Are mutually orthogonal, so:

<math> <mrow> <mo>|</mo> <mo>|</mo> <msubsup> <munder> <mi>w</mi> <mo>&OverBar;</mo> </munder> <mi>j</mi> <mi>H</mi> </msubsup> <msub> <munder> <mi>w</mi> <mo>&OverBar;</mo> </munder> <mi>l</mi> </msub> <mo>|</mo> <mo>|</mo> <mo>=</mo> <mn>0</mn> <mo>,</mo> </mrow> </math> wherein j is more than or equal to 0 and less than or equal to 3, l is more than or equal to 0 and less than or equal to 3, and j is not equal to l formula (4)

Fig. 6 shows an exemplary signal constellation for QPSK, which is used in IEEE 802.16. The signal constellation comprises four signal points corresponding to four possible modulation symbols for QPSK. Each modulation symbol is x_i+jx_qComplex value of the form, wherein x_iIs the real part, x_qIs the imaginary part. Real part x_iMay have a value of +1.0 or-1.0, imaginary part x_qAnd may also have a value of +1.0 or-1.0. The four modulation symbols are denoted as P0, P1, P2, and P3.

Eight different permutations (syndromes) of QPSK modulation symbols P0, P1, P2, and P3 may be used to form eight vectorsv ₀Tov ₇In which P is_i，kE.g. { P0, P1, P2, P3 }. Similarly, four different permutations (syndromes) of QPSK modulation symbols P0, P1, P2, and P3 may be used to form four vectorsw ₀Tow ₃In which P is_j，kE.g. { P0, P1, P2, P3 }. The first two columns of Table 1 are given according to oneEight vectors of seed designv ₀Tov ₇Eight modulation symbols in each of them. The last two columns of Table 1 give four vectors according to a designw ₀Tow ₃Four modulation symbols in each of them. Vectors may also be formed in other waysv ₀Tov ₇Sum vectorw ₀Tow ₃。

TABLE 1

Vector index i	Vector quantityv iModulation symbol in
		0	P0，P1，P2，P3，P0，P1，P2，P3
1	P0，P3，P2，P1，P0，P3，P2，P1
		2	P0，P0，P1，P1，P2，P2，P3，P3
3	P0，P0，P3，P3，P2，P2，P1，P1
		4	P0，P0，P0，P0，P0，P0，P0，P0
5	P0，P2，P0，P2，P0，P2，P0，P2
		6	P0，P2，P0，P2，P2，P0，P2，P0
7	P0，P2，P2，P0，P2，P0，P0，P2

Vector index j	Vector quantityw jModulation symbol in
		0	P0，P0，P0，P0
1	P0，P2，P0，P2
		2	P0，P1，P2，P3
3	P1，P0，P3，P2

A signaling message for a primary fast feedback channel may be mapped to a set of 8-element vectors, and this set of 8-element vectors may be sent to convey the message. For example, a 4-bit message or a 6-bit message may be mapped to a set of six 8-element vectors, and each 8-element vector may be transmitted on 8 subcarriers in one tile of the primary fast feedback channel. An example of mapping a 4-bit message to a set of six 8-element vectors and an example of mapping a 6-bit message to a set of six 8-element vectors are described in the aforementioned IEEE802.16 document.

A signaling message for a secondary fast feedback channel may be mapped to a set of 4-element vectors, which may be sent to convey the message. For example, a 4-bit message may be mapped to a set of six 4-element vectors, and each 4-element vector may be transmitted on 4 subcarriers in one tile of the secondary fast feedback channel. An example of mapping a 4-bit message to a set of six 4-element vectors is described in the aforementioned IEEE802.16 document.

One or both subscriber stations may send signaling messages on the primary and secondary fast feedback channels on a chip shared by the primary and secondary fast feedback channels. The base station may obtain 12 received symbols from the 12 subcarriers of each tile. The base station may demultiplex the 12 received symbols from each tile m to obtain: (i) vector of eight received symbols from eight subcarriers of the primary fast feedback channelr _m，pAnd (ii) a vector of four received symbols from four subcarriers of a secondary fast feedback channelr _m，s. The base station can subtend quantitiesr _m，pAndr _m，snon-coherent detection to determine vectors transmitted on primary and secondary fast feedback channelsv _mAndw _m. Noncoherent detection refers to detection performed without using a pilot reference.

In one design, the base station may transmit the received vector for each tile mr _m，pWith eight possible vectorsv ₀Tov ₇Performs the following correlation calculation for non-coherent detection of the primary fast feedback channel:

<math> <mrow> <msub> <mi>M</mi> <mrow> <mi>m</mi> <mo>,</mo> <mi>i</mi> </mrow> </msub> <mo>=</mo> <mo>|</mo> <mo>|</mo> <msubsup> <munder> <mi>v</mi> <mo>&OverBar;</mo> </munder> <mi>i</mi> <mi>H</mi> </msubsup> <msub> <munder> <mi>r</mi> <mo>&OverBar;</mo> </munder> <mrow> <mi>m</mi> <mo>,</mo> <mi>p</mi> </mrow> </msub> <mo>|</mo> <mo>|</mo> <mo>,</mo> </mrow> </math> where i is 0, 7, formula (5)

Wherein M is_m，iIs the m-median vector of the slicev _iThe correlation calculation result of (1).

For each tile m, the base station may find the vector with the largest correlation result, as shown in the following equation:

$d_m=\arg \left(\underset{i=0,...,7}{\mathrm{Max}}\right\{M_{m,i}\left\}\right)$ formula (6)

For each tile m, the base station may receive the vector according to tile mr _m，pTo determine a vectorv _m，dIs sent in chip m of the primary fast feedback channel. The base station may acquire the detected six vectors for all six tiles of the primary fast feedback channelv _0，dTov _5，dA set of such vectors, and the message sent on the primary fast feedback channel may be determined from this set of six vectors detected.

In one design, the base station may transmit the received vector for each tile mr _m，sWith four possible vectorsw ₀Tow ₃Performs the following correlation calculation for non-coherent detection of the secondary fast feedback channel:

<math> <mrow> <msub> <mi>M</mi> <mrow> <mi>m</mi> <mo>,</mo> <mi>j</mi> </mrow> </msub> <mo>=</mo> <mo>|</mo> <mo>|</mo> <msubsup> <munder> <mi>w</mi> <mo>&OverBar;</mo> </munder> <mi>j</mi> <mi>H</mi> </msubsup> <msub> <munder> <mi>r</mi> <mo>&OverBar;</mo> </munder> <mrow> <mi>m</mi> <mo>,</mo> <mi>s</mi> </mrow> </msub> <mo>|</mo> <mo>|</mo> <mo>,</mo> </mrow> </math> where j is 0, 3, formula (7)

Wherein M is_m，jIs the m-median vector of the slicew _jThe correlation calculation result of (1).

For each tile m, the base station may find the vector with the largest correlation result, as shown in the following equation:

$e_m=\arg \left(\underset{j=0,...,3}{\mathrm{Max}}\right\{M_{m,j}\left\}\right)$ formula (8)

For each tile m, the base station may receive the vector according to tile mr _m，sTo determine a vectorw _m，eIs sent in chip m of the secondary fast feedback channel. The base station may acquire the detected six vectors for all six tiles of the secondary fast feedback channelw _0，eTow _5，eA set of six vectors detected, and a message sent on the secondary fast feedback channel may be determined from this set of six vectors detected.

In another design, the base station may perform non-coherent detection on the primary fast feedback channel as follows:

<math> <mrow> <msub> <mi>A</mi> <mi>c</mi> </msub> <mo>=</mo> <munderover> <mi>&Sigma;</mi> <mrow> <mi>m</mi> <mo>=</mo> <mn>0</mn> </mrow> <mn>5</mn> </munderover> <msub> <mi>G</mi> <mi>m</mi> </msub> <mo>&CenterDot;</mo> <mo>|</mo> <mo>|</mo> <msubsup> <munder> <mi>v</mi> <mo>&OverBar;</mo> </munder> <mrow> <mi>m</mi> <mo>,</mo> <mi>c</mi> </mrow> <mi>H</mi> </msubsup> <msub> <munder> <mi>r</mi> <mo>&OverBar;</mo> </munder> <mrow> <mi>m</mi> <mo>,</mo> <mi>p</mi> </mrow> </msub> <mo>|</mo> <mo>|</mo> </mrow> </math> formula (9)

Wherein,v _m，cis the vector of message c sent in slice m,

G_mis the scaling factor of slice m, and

A_cis a measure of the message c on the primary fast feedback channel.

In the design shown in equation (9), the base station may correlate the set of six received vectors for the six tiles of the primary fast feedback channel with the set of six vectors for each possible message that may be sent on the primary fast feedback channel. The base station may have the best metric a_cIs selected as the message received on the primary fast feedback channel. The base station may perform non-coherent detection on the secondary fast feedback channel in a similar manner. The base station may also detect the primary and secondary fast feedback channels in other manners.

Fig. 7 shows a design of a process 700 performed by a subscriber station or some other entity to send signaling. The subscriber station may determine (e.g., via an allocation message) time frequency resources comprising a first portion of time frequency resources for a first feedback channel and a second portion of time frequency resources for a second feedback channel (block 712). The first and second feedback channels may correspond to primary and secondary fast feedback channels, respectively, in IEEE802.16, or may be other feedback channels. The subscriber station may send signaling on the first feedback channel using the first portion of time frequency resources and/or on the second feedback channel using the second portion of time frequency resources (block 714).

The time-frequency resources of the first and second feedback channels may comprise at least one tile (e.g., six tiles). Each tile may include at least one subcarrier in each of at least one symbol period. The first and second portions of time frequency resources may comprise disjoint first and second subsets of subcarriers in each tile, respectively. In one design, each tile includes four subcarriers in each of three symbol periods. For example, as shown in fig. 5, the first portion of time frequency resources for the first feedback channel may include all subcarriers in each tile except for subcarriers located at the four corners of each tile. For example, as shown in fig. 5, the second portion of time frequency resources for the second feedback channel may include four subcarriers at four corners of each tile. The first and second portions of time frequency resources may also include other subsets of subcarriers in each tile.

In one design, a subscriber station may send signaling on a first feedback channel using a first portion of time frequency resources and another subscriber station may use a second portion of time frequency resources. In another design, the subscriber station may send signaling on the second feedback channel using the second portion of time frequency resources and another subscriber station may use the first portion of time frequency resources. In yet another design, the subscriber station may send signaling on the first feedback channel using the first portion of time frequency resources and on the second feedback channel using the second portion of time frequency resources.

For block 714, the subscriber station may transmit a vector of modulation symbols of a first length (e.g., eight) on a first portion of time frequency resources for a first feedback channel. Alternatively or additionally, the subscriber station may transmit a second length (e.g., four) vector of modulation symbols on a second portion of time frequency resources for a second feedback channel.

Fig. 8 shows a design of an apparatus 800 for sending signaling. The apparatus 800 comprises: a module 812 for determining time frequency resources comprising a first part of time frequency resources for a first feedback channel and a second part of time frequency resources for a second feedback channel, and a module 814 for sending signaling on the first feedback channel and/or the second feedback channel.

Fig. 9 shows a design of a process 900 performed by a base station or some other entity for receiving signaling. The base station may receive a first feedback channel on a first portion of time frequency resources (block 912) and a second feedback channel on a second portion of time frequency resources (block 914). The time-frequency resources for the first and second feedback channels may include at least one tile (tile), where each tile may include at least one subcarrier in each of at least one symbol period. The first and second portions of time frequency resources may comprise disjoint first and second subsets of subcarriers in each tile, respectively. The first and second feedback channels may correspond to primary and secondary fast feedback channels, respectively, in IEEE802.16, or may be other feedback channels. The base station may receive the first and second feedback channels from a single subscriber station or from two subscriber stations.

For block 912, the base station may obtain a vector of received symbols of a first length (e.g., eight) for the first feedback channel. For block 914, the base station may obtain a vector of received symbols of a second length (e.g., four) for a second feedback channel. The base station may be based on a first set of vectors (e.g., vectors) of modulation symbols that may be used for the first feedback channelv ₀Tov ₇) To perform detection (e.g., non-coherent detection) on the received symbol vector for the first feedback channel (block 916). The base station may use a second set of modulation symbol vectors (e.g., vectors) for the second feedback channelw ₀Tow ₃) To detect a vector of received symbols for the second feedback channel (block 918). In one design, for each feedback channel, the base station may perform detection for each tile and then determine the signaling messages received on the feedback channel based on the results of the obtained correlation calculations for all tiles. In another design, for each feedback channel, the base station may detect all tiles for each possible signaling message and then determine the messages received on the feedback channel based on the results of the correlation calculations for all possible messages obtained.

Fig. 10 shows a design of an apparatus 1000 for receiving signaling. The apparatus 1000 comprises: a module 1012 for receiving a first feedback channel on a first portion of time frequency resources; a module 1014 for receiving a second feedback channel on a second portion of time frequency resources; a module 1016 for detecting a received symbol vector of the first feedback channel; and a module 1018 for detecting the received symbol vector of the second feedback channel.

The modules in fig. 8 and 10 may include: processors, electronics devices, hardware devices, electronics components, logic circuits, memory, etc., or any combination thereof.

Fig. 11 shows a block diagram of a design of two subscriber stations 120x and 120y and a base station 110, and the subscriber stations 120x and 120y and the base station 110 may be two subscriber stations and one base station in fig. 1. Subscriber station 120x is equipped with a single antenna 1132x, subscriber station 120y is equipped with multiple (T) antennas 1132a through 1132T, and base station 110 is equipped with multiple (R) antennas 1152a through 1152R. In general, each subscriber station and base station may be equipped with any number of antennas. Each antenna may be a physical antenna or an antenna array.

At each subscriber station 120, a Transmit (TX) data and signaling processor 1120 receives data from a data source 1112, processes (e.g., formats, codes, interleaves, and symbol maps) the data, and generates modulation symbols for the data (or, alternatively, only data symbols). Processor 1120 also receives signaling (e.g., for the primary and/or secondary fast feedback channels) from a controller/processor 1140, processes the signaling, and generates modulation symbols for the signaling (or only signaling symbols). Processor 1120 may also generate and multiplex pilot symbols with the data and signaling symbols.

At subscriber station 120y, a TX MIMO processor 1122y performs transmitter spatial processing on the data, signaling, and/or pilot symbols. Processor 1122y may perform direct MIMO mapping, precoding, beamforming, and the like. The symbols may be transmitted from one antenna for direct MIMO mapping, or from multiple antennas for precoding and beamforming. Processor 1122y may provide T output symbol streams to T Modulators (MODs) 1130a through 1130T. At subscriber station 120x, a processor 1120x provides a single output symbol stream to a modulator 1130 x. Each modulator 1130 may perform modulation (e.g., for OFDM) on the output symbols to obtain output chips (chips). Each modulator 1130 may further process (e.g., convert to analog, filter, amplify, and upconvert) its output chips and generate an uplink signal. At subscriber station 120x, the single uplink signal from modulator 1130x is transmitted via antenna 1132 x. At subscriber station 120y, T uplink signals from modulators 1130a through 1130T are transmitted through T antennas 1132a through 1132T, respectively.

At base station 110, R antennas 1152a through 1152R receive the uplink signals from subscriber stations 120x and 120y and possibly other subscriber stations. Each antenna 1152 may provide a received signal to a respective demodulator (DEMOD) 1154. Each demodulator 1154 processes (e.g., filters, amplifies, frequency downconverts, and digitizes) its received signal to obtain samples. Each demodulator 1154 may also perform demodulation (e.g., for OFDM) on the samples to obtain received symbols. A Receive (RX) MIMO processor 1160 may estimate the channel responses of the different subscriber stations based on the received pilot symbols, perform MIMO detection on the received data symbols, and provide data symbol estimates. An RX data and signaling processor 1170 then processes (e.g., symbol demaps, deinterleaves, and decodes) the data symbol estimates and provides decoded data to a data sink 1172. Processor 1170 also detects received signaling symbols for the primary and secondary fast feedback channels and provides detected signaling to a controller/processor 1180.

Base station 110 may send data and signaling to subscriber stations. Data from a data source 1190 and signaling from controller/processor 1180 may be processed by a TX data and signaling processor 1192, further processed by a TX MIMO processor 1194, and then processed by modulators 1154a through 1154R to generate R downlink signals, which may be transmitted via R antennas 1152a through 1152R. At each subscriber station 1110, the downlink signals from base station 110 may be received by one or more antennas 1132 and processed by one or more demodulators 1130 to obtain received symbols. At subscriber station 120x, the received symbols may be processed by an RX data and signaling processor 1136x to recover the data and signaling sent by base station 110 to subscriber station 120 x. At subscriber station 120y, the received symbols may be processed by an RX MIMO processor 1134y and further processed by an RX data and signaling processor 1136y to recover the data and signaling sent by base station 110 to subscriber station 120 y.

Controllers/ processors 1140x, 1140y, and 1180 may control the operation of various processing units at subscriber stations 120x and 120y and base station 110, respectively. Controllers/processors 1140x and 1140y may perform or control process 700 in fig. 7 and/or other processes for the techniques described herein. Controller/processor 1180 may perform or control process 900 in fig. 9 and/or other processes for the techniques described herein. Memories 1142x, 1142y, and 1182 may store data and program codes for subscriber stations 120x and 120y and base station 110, respectively. A scheduler 1184 may schedule subscriber stations for transmission on the downlink and/or uplink.

The techniques described herein may be implemented in various ways. For example, these techniques may be implemented in hardware, firmware, software, or a combination thereof. For a hardware implementation, the processing units of each entity (e.g., a subscriber station or base station) may be implemented within one or more Application Specific Integrated Circuits (ASICs), Digital Signal Processors (DSPs), Digital Signal Processing Devices (DSPDs), Programmable Logic Devices (PLDs), Field Programmable Gate Arrays (FPGAs), processors, controllers, micro-controllers, microprocessors, electronic devices, other electronic units designed to perform the functions described herein, a computer, or a combination thereof.

For a firmware and/or software implementation, the techniques may be implemented with modules (e.g., procedures, functions, and so on) that perform the functions described herein. The firmware and/or software instructions may be stored in a memory (e.g., memory 1142x, 1142y, or 1182 in fig. 11) and executed by a processor (e.g., processor 1140x, 1140y, or 1180). The memory may be implemented within the processor or external to the processor. The firmware and/or software instructions may also be stored in other processor-readable media, such as: random Access Memory (RAM), read-only memory (ROM), non-volatile random access memory (NVRAM), programmable read-only memory (PROM), electrically erasable PROM (eeprom), flash memory, Compact Disc (CD), magnetic or optical data storage devices, and the like.

The previous description of the disclosure is provided to enable any person skilled in the art to make or use the disclosure. Various modifications to the disclosure will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other variations without departing from the spirit or scope of the disclosure. Thus, the present disclosure is not intended to be limited to the examples described herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims (37)

1. An apparatus for wireless communication, comprising:

at least one processor configured to:

determining time frequency resources, wherein the time frequency resources comprise a first part of time frequency resources used for a first feedback channel and a second part of time frequency resources used for a second feedback channel; and transmitting signaling on the first feedback channel or the second feedback channel or both the first feedback channel and the second feedback channel, wherein the time-frequency resources comprise at least one tile, each tile comprising at least one subcarrier in each of at least one symbol period; and the first portion of time frequency resources and the second portion of time frequency resources comprise a first subset and a second subset of subcarriers in each of the at least one tile, respectively, which are disjoint;

a memory coupled to the at least one processor.

2. The apparatus of claim 1, wherein:

the time-frequency resource includes six tiles, each tile including four subcarriers in each of three symbol periods.

3. The apparatus of claim 2, wherein:

the first part of time frequency resources comprise all subcarriers except four subcarriers at four corners of each slice; and

the second portion of time frequency resources comprises the four subcarriers at the four corners of each tile.

4. The apparatus of claim 1, wherein:

the at least one processor is configured to transmit signaling on the first feedback channel using the first portion of time-frequency resources; and is

The second portion of time frequency resources is used by another subscriber station.

5. The apparatus of claim 1, wherein:

the at least one processor is configured to transmit signaling on the second feedback channel using the second portion of time-frequency resources; and is

The first portion of time frequency resources is used by another subscriber station.

6. The apparatus of claim 1, wherein the at least one processor is configured to:

transmitting signaling on the first feedback channel using the first portion of time frequency resources and on the second feedback channel using the second portion of time frequency resources.

7. The apparatus of claim 1, wherein to send signaling on the first feedback channel, the at least one processor is configured to:

and transmitting a modulation symbol vector with a first length on the first part of time frequency resources.

8. The apparatus of claim 7, wherein to send signaling on the second feedback channel, the at least one processor is configured to:

and transmitting a modulation symbol vector with a second length on the second part of time frequency resources.

9. The apparatus of claim 1, wherein:

the first feedback channel and the second feedback channel correspond to a primary fast feedback channel and a secondary fast feedback channel in IEEE 802.16.

10. A method for wireless communication, comprising:

determining time frequency resources, wherein the time frequency resources comprise a first part of time frequency resources for a first feedback channel and a second part of time frequency resources for a second feedback channel, the time frequency resources comprise at least one tile, each tile comprises at least one subcarrier in each symbol period of at least one symbol period, and the first part of time frequency resources and the second part of time frequency resources respectively comprise a first subset and a second subset which are not intersected with each other, of the subcarriers in each tile in the at least one tile; and

transmitting signaling on the first feedback channel or on the second feedback channel or on both the first feedback channel and the second feedback channel.

11. The method of claim 10, wherein the sending signaling comprises:

and transmitting a modulation symbol vector with a first length on the first part of time frequency resources.

12. The method of claim 11, wherein the sending signaling further comprises:

and transmitting a modulation symbol vector with a second length on the second part of time frequency resources.

13. An apparatus for wireless communication, comprising:

means for determining time-frequency resources, the time-frequency resources comprising a first portion of time-frequency resources for a first feedback channel and a second portion of time-frequency resources for a second feedback channel, the time-frequency resources comprising at least one tile, each tile comprising at least one subcarrier in each symbol period of at least one symbol period, the first portion of time-frequency resources and the second portion of time-frequency resources comprising disjoint first and second subsets of subcarriers in each tile of the at least one tile, respectively; and

means for transmitting signaling on the first feedback channel or the second feedback channel or both the first feedback channel and the second feedback channel.

14. The apparatus of claim 13, wherein the means for sending signaling comprises:

means for transmitting a vector of modulation symbols of a first length on the first portion of time frequency resources.

15. The apparatus of claim 14, wherein the means for sending signaling further comprises:

means for transmitting a vector of modulation symbols of a second length on the second portion of time frequency resources.

16. A processor-readable medium including instructions stored thereon, comprising:

a first set of instructions for determining time frequency resources, the time frequency resources comprising a first portion of time frequency resources for a first feedback channel and a second portion of time frequency resources for a second feedback channel, the time frequency resources comprising at least one tile, each tile comprising at least one subcarrier in each symbol period of at least one symbol period, the first portion of time frequency resources and the second portion of time frequency resources comprising disjoint first and second subsets of subcarriers in each tile of the at least one tile, respectively; and

a second set of instructions for sending signaling on the first feedback channel or on the second feedback channel or on both the first feedback channel and the second feedback channel.

17. The processor-readable medium of claim 16, wherein the second set of instructions comprises:

a third set of instructions for transmitting a vector of modulation symbols of a first length on the first portion of time frequency resources.

18. The processor-readable medium of claim 17, wherein the second set of instructions further comprises:

a fourth set of instructions for transmitting a vector of modulation symbols of a second length on the second portion of time frequency resources.

19. An apparatus, comprising:

at least one processor configured to:

receiving a first feedback channel on a first portion of time frequency resources and a second feedback channel on a second portion of time frequency resources, wherein the time frequency resources for the first feedback channel and the second feedback channel comprise at least one tile, each tile comprising at least one subcarrier in each symbol period of at least one symbol period, and wherein the first portion of time frequency resources and the second portion of time frequency resources comprise disjoint first and second subsets of subcarriers in each tile of the at least one tile, respectively; and a memory coupled to the at least one processor.

20. The apparatus of claim 19, wherein:

the time-frequency resources for the first and second feedback channels comprise six tiles, each tile comprising four subcarriers in each of three symbol periods.

21. The apparatus of claim 20, wherein:

the first portion of time frequency resources for the first feedback channel includes all subcarriers in each tile except for four subcarriers at four corners of each tile; and

the second portion of time frequency resources for the second feedback channel includes the four subcarriers at the four corners of each tile.

22. The apparatus of claim 19, wherein the at least one processor is configured to:

receiving the first feedback channel and the second feedback channel from a single subscriber station.

23. The apparatus of claim 19, wherein the at least one processor is configured to:

the first feedback channel and the second feedback channel are received from two subscriber stations.

24. The apparatus of claim 19, wherein the at least one processor is configured to:

obtaining a vector of received symbols of a first length for the first feedback channel; and

obtaining a vector of received symbols of a second length for the second feedback channel.

25. The apparatus of claim 19, wherein the at least one processor is configured to:

a vector of received symbols for the first feedback channel is detected from a first set of vectors of modulation symbols available for the first feedback channel.

26. The apparatus of claim 25, wherein the at least one processor is configured to:

detecting a vector of received symbols for the second feedback channel according to a second set of vectors of modulation symbols available for the second feedback channel.

27. A method, comprising:

receiving a first feedback channel on a first portion of time frequency resources; and receiving a second feedback channel on a second portion of time frequency resources, wherein the time frequency resources for the first feedback channel and the second feedback channel comprise at least one tile, each tile comprising at least one subcarrier in each symbol period of at least one symbol period, and wherein the first portion of time frequency resources and the second portion of time frequency resources comprise disjoint first and second subsets of subcarriers in each tile of the at least one tile, respectively.

28. The method of claim 27, wherein:

receiving the first feedback channel and the second feedback channel from a single subscriber station.

29. The method of claim 27, wherein:

the first feedback channel and the second feedback channel are received from two subscriber stations.

30. The method of claim 27, wherein the step of,

wherein the receiving the first feedback channel comprises: obtaining a vector of received symbols of a first length for the first feedback channel, an

Wherein the receiving the second feedback channel comprises: obtaining a vector of received symbols of a second length for the second feedback channel.

31. The method of claim 27, further comprising:

detecting a vector of received symbols for the first feedback channel in accordance with a first set of vectors of modulation symbols available for the first feedback channel; and

detecting a vector of received symbols for the second feedback channel according to a second set of vectors of modulation symbols available for the second feedback channel.

32. An apparatus, comprising:

means for receiving a first feedback channel on a first portion of time-frequency resources; and

means for receiving a second feedback channel on a second portion of time frequency resources,

wherein the time-frequency resources for the first feedback channel and the second feedback channel comprise at least one tile, each tile comprising at least one subcarrier in each symbol period of at least one symbol period, an

Wherein the first portion of time frequency resources and the second portion of time frequency resources respectively include a first subset and a second subset of subcarriers in each of the at least one tile that are disjoint.

33. The apparatus as set forth in claim 32, wherein,

wherein the means for receiving the first feedback channel comprises: means for obtaining a vector of received symbols of a first length for the first feedback channel, an

Wherein the means for receiving the second feedback channel comprises: means for obtaining a vector of received symbols of a second length for the second feedback channel.

34. The apparatus of claim 32, further comprising:

means for detecting a vector of received symbols for the first feedback channel from a first set of vectors of modulation symbols available for the first feedback channel; and

means for detecting vectors of received symbols for the second feedback channel based on a second set of vectors of modulation symbols available for the second feedback channel.

35. A processor-readable medium including instructions stored thereon, comprising:

a first set of instructions for receiving a first feedback channel on a first portion of time frequency resources; and

a second set of instructions for receiving a second feedback channel on a second portion of time frequency resources,

wherein the time-frequency resources for the first feedback channel and the second feedback channel comprise at least one tile, each tile comprising at least one subcarrier in each symbol period of at least one symbol period, an

Wherein the first portion of time frequency resources and the second portion of time frequency resources respectively include a first subset and a second subset of subcarriers in each of the at least one tile that are disjoint.

36. The processor-readable medium of claim 35, wherein:

the first set of instructions includes: a third set of instructions for obtaining a vector of received symbols of a first length for the first feedback channel, and wherein

The second set of instructions includes: a fourth set of instructions for obtaining a vector of received symbols of a second length for the second feedback channel.

37. The processor-readable medium of claim 35, further comprising:

a third set of instructions for detecting a vector of received symbols for the first feedback channel based on a first set of vectors of modulation symbols available for the first feedback channel; and

a fourth set of instructions for detecting vectors of received symbols for the second feedback channel based on a second set of vectors of modulation symbols available for the second feedback channel.

Images