WO2009003420A1

WO2009003420A1 - A method, apparatus and system for implementing the multiple access

Info

Publication number: WO2009003420A1
Application number: PCT/CN2008/071538
Authority: WO
Inventors: Sheng Liu; Xin Chang; Mingyang Sun
Original assignee: Huawei Technologies Co., Ltd.
Priority date: 2007-07-04
Filing date: 2008-07-03
Publication date: 2009-01-08
Also published as: CN101340273A; CN101340273B

Abstract

A method for implementing the multiple access transmission includes that: dividing a modulation symbol sequence to be transmitted into symbol sub-blocks, and determining the map relation among the symbol sub-block, time frequency two-dimensional physical resource block and basic physical resource block; then performing orthogonal transformations spreading respectively for the symbol sub-blocks by using inter-orthogonal spreading sequence, which have the map relation with the same time frequency two-dimensional physical resource, and obtaining a symbol orthogonal transformation spreading sequence of each symbol sub-block; at last, overlaying the symbol orthogonal transformation spreading sequence of the symbol sub-blocks which have the map relation with the same time frequency two-dimensional physical resource to obtain an overlaying signal, and mapping the overlaying signals into the corresponding basic physical resource block. The transmitting apparatus, receiving method and apparatus, and system for realizing the multiple access are also provided. By applying this invention, the multiple access orthogonal and discrete frequency diversity gain of multiple users can be implemented synchronously and the flexibility of resource allocation and dispatching is improved.

Description

Multiple access method, device and system

The present invention relates to mobile communication technologies, and in particular, to a multiple access access transmission method and apparatus, a multiple access reception method and apparatus, and a multiple access system. Background technique

Orthogonal Frequency Division Multiplexing (OFDM) technology is one of the key technologies for future mobile communication systems. Fig. 1 shows a specific example of allocation and use of channel resources in the existing OFDM modulation scheme. Referring to FIG. 1 , in the OFDM modulation mode, a channel resource is a time-frequency two-dimensional structure, and a basic physical resource block (PRB) is a basic component unit of a channel resource, and a time-frequency two-dimensional physical resource block includes several consecutive components. The basic physical resource block, the time-frequency two-dimensional physical resource block is the basic unit for mapping the data to be transmitted to the physical layer. FIG. 2 is a schematic diagram showing the structure of a conventional time-frequency two-dimensional physical resource block. Referring to FIG. 2, the time-frequency two-dimensional physical resource block includes Nt consecutive OFDM symbols in time, and includes Nf consecutive OFDM subcarriers in a frequency domain, and the number of modulation symbols that can be carried is N=Nt X Nf. The modulation symbols include pilot symbols and data symbols.

In the prior art, there is a multiple access technology that combines OFDM technology and spread spectrum technology, which is called Block Repeat Orthogonal Frequency Division Multiple Access (BR-OFDMA). This technology introduces the concept of block repetition code based on OFDM technology, aiming to use the frequency diversity gain of block repetition to combat frequency selective fading, and solve the interference problem between users in different cells through joint detection technology, and improve the frequency band utilization at the edge of the cell. rate. The following is a brief introduction to the existing BR-OFDMA and related concepts:

In the wireless channel, due to the presence of multipath, the signal received by the receiving end is actually a superposition of multiple transmitted signals with different fading and delay, which causes dispersion in time, that is, delay spread. The reciprocal of the maximum delay spread is defined as the coherent bandwidth. When the channel bandwidth of the system is greater than the coherent bandwidth, the fading of each frequency component after the signal components of different frequencies pass through the wireless channel is different, which is characterized by frequency selective fading. Therefore, from a frequency domain perspective, the delay spread of multipath signals leads to frequency selective fading.

In order to combat frequency selective fading, frequency diversity techniques are widely used in mobile communication systems. A typical frequency diversity technique is to transmit the same data at different frequencies, if the frequency spacing of each carrier frequency Relatively far, for example, if the frequency interval of each carrier frequency exceeds the coherence bandwidth, the signals transmitted by each carrier frequency are also uncorrelated. Through the frequency diversity technique, the effect of averaging channel fading can be obtained, and the allocated subcarriers are prevented from being deeply fading, and the frequency diversity gain is obtained.

Fig. 3 is a schematic diagram showing the principle of modulation processing of data to be transmitted using the BR-OFDMA method. Referring to Figure 3, the process is:

Step 1: The channel coded and other processed bit (bit) data is modulated by the symbol modulation module 110 into a modulation symbol sequence, and the modulation symbol sequence is divided to generate a data symbol block (DB). In this step, the length of the DB is equal to the number of modulation symbols that can be carried by the time-frequency two-dimensional physical resource block.

Step 2: Input the DB into the block unit modulation module 120 for mapping to generate a unit block (BU). Step 3: Enter BU into the Block Modulation Module (BR Modulation) 130 for repeat weighting. Step 4: The modulation data obtained by repeating the weighting is serial/parallel transformed according to the time-frequency domain unit of the data transmission, mapped to different OFDM basic physical resource blocks, and then subjected to inverse fast Fourier transform (IFFT) transformation to generate time domain signals. send.

In the third step above, the function of the block repetition modulation module 130 is to repeatedly weight the unit blocks. The process of repeating the weighting is specifically as follows:

The number of block repetitions is determined in advance according to the needs of the user and the channel, and a block repetition weighting factor sequence (or called a repetition code RC) and a correspondence relationship between the unit block and the time-frequency two-dimensional physical resource block are set. Here, the number of block repetitions is the length of the extended sequence in the spreading technique, and RC is an extended sequence in the spreading technique. If the number of block repetitions is n, then one unit block will be correspondingly transmitted to n time-frequency two-dimensional physical resource blocks. If multiple users share the same time-frequency resource, a set of mutually orthogonal spreading sequences needs to be set for the multiple users; otherwise, complex joint detection techniques need to be used at the receiving end.

When receiving the unit block from the block unit modulation module 120, the unit block is repeatedly weighted (ie, expanded) using the corresponding RC, and the result of the repeated weighting is mapped into the corresponding time-frequency two-dimensional physical resource block. .

FIG. 4 is a schematic structural diagram of unit block resource allocation of a single user in the existing BR-OFDMA modulation mode. FIG. 5 is a schematic structural diagram of resource block resource allocation of two users in the existing BR-OFDMA modulation mode. In Figures 4 and 5, the same unit block is repeated 6 times. In Figure 5, two users occupy the same time-frequency resource for block repeat transmission, along the direction of the repeating code axis, the upper part is the unit block of user 1, and the lower part is the unit block of user 2, that is, each unit block Repeat code to distinguish different units The modulation symbol stream of the block.

The inventors of the present application found in the process of implementing the present invention that the existing BR-OFDMA technology has the following disadvantages:

In one aspect, when the unit blocks of multiple users are repeatedly weighted (ie, extended) on consecutive time-frequency two-dimensional physical resources, if the sum of the subcarrier bandwidths occupied by the consecutive time-frequency two-dimensional physical resources does not exceed The coherence bandwidth can be considered to be spread over a flat channel, so the difference between the actual channel response and the estimated channel response is approximately fixed, so that the orthogonality of the extended sequence is maintained, that is, the multi-user multiple address is positive. The intersection is maintained; and when the unit blocks of multiple users are repeatedly weighted on the discretely distributed time-frequency two-dimensional physical resources, the difference between the actual channel response and the estimated channel response will not be fixed. This will not maintain multi-user orthogonality of the multi-user, introducing additional multi-user interference.

On the other hand, when the unit blocks of multiple users are repeatedly weighted on consecutive time-frequency two-dimensional physical resources, if frequency selective scheduling is not performed, only random frequency diversity can be obtained except for the repetitive gain. Gain; and when weighting is repeated on discrete time-frequency two-dimensional physical resources, in addition to the repetitive gain, discrete frequency diversity gains can be obtained, which would exceed the random frequency diversity gain.

In addition, in order to achieve multiplexing of time-frequency resources, users using the same set of spreading sequences must transmit on the same time-frequency two-dimensional physical resources, which limits the flexibility of resource allocation and scheduling, especially in the frequency. When selectively scheduling, the frequency diversity gain of multiple users will be limited.

It can be seen from the above that when the existing BR-OFDMA technology repeats the weighting on the continuous time-frequency two-dimensional physical resources, multi-user multiple access orthogonality is obtained, but discrete frequency diversity gain cannot be obtained; and the discrete time-frequency is obtained. When the weight is repeated on the two-dimensional physical resources, the discrete frequency diversity gain will be obtained, but the multi-user orthogonality of multiple users cannot be maintained. That is to say, the existing BR-OFDMA technology cannot simultaneously achieve multi-user orthogonality of multiple users. Discrete frequency diversity gain. Moreover, the flexibility of resource allocation and scheduling is poor. Summary of the invention

In view of this, an embodiment of the present invention provides a multiple access access transmitting method, a multiple access receiving method, a transmitting device for implementing multiple access, and a receiving device for implementing multiple access, Achieve multi-user multiple access orthogonal and discrete frequency diversity gains, and enhance resource allocation and scheduling flexibility.

To achieve the above objective, the technical solution of the embodiment of the present invention is specifically implemented as follows:

A multiple access transmission method includes: Separating the sequence of modulation symbols to be transmitted into symbol sub-blocks, where the length of the symbol sub-blocks is less than or equal to the number of modulation symbols that can be carried by the time-frequency two-dimensional physical resource block;

Determining the mapping relationship between the symbol sub-block, the time-frequency two-dimensional physical resource block, and the basic physical resource block; and using the mutually orthogonal extended sequence for the symbol sub-blocks that have a mapping relationship with the same time-frequency two-dimensional physical resource block Transmitting the transform to obtain a symbol orthogonal transform spreading sequence of each symbol sub-block; superimposing the symbol orthogonal transform spreading sequence of the symbol sub-block having a mapping relationship with the same time-frequency two-dimensional physical resource block to obtain a superimposed signal, and superimposing the signal Map to the corresponding basic physical resource block.

A transmitting device for implementing multiple access, comprising:

a segmentation module, configured to divide a modulation symbol to be transmitted into a symbol sub-block, where the length of the symbol sub-block is less than or equal to a number of modulation symbols that can be carried by the time-frequency two-dimensional physical resource block;

a symbol sub-block mapping module, configured to determine a mapping relationship between a symbol sub-block, a time-frequency two-dimensional physical resource block, and a basic physical resource block;

And an orthogonal transform extension module, configured to send, to the basic physical resource block mapping module, a symbol orthogonal transform extension sequence of the symbol sub-blocks that have a mapping relationship with the same time-frequency two-dimensional physical resource block;

And a basic physical resource block mapping module, configured to superimpose a symbol orthogonal transform extension sequence of a symbol sub-block that has a mapping relationship with the same time-frequency two-dimensional physical resource block to obtain a superimposed signal, and map the superimposed signal to the corresponding basic physical resource block. .

A multiple access receiving method includes:

De-mapping a symbol orthogonal transform extension sequence mapped onto the time-frequency two-dimensional physical resource block corresponding to the basic physical resource block from the superposed signal of the basic physical resource block;

Despreading the symbol orthogonal transform spreading sequence to obtain a symbol sub-block corresponding to each time-frequency two-dimensional physical resource block;

Decoding each symbol sub-block according to a mapping relationship between the symbol sub-block and the time-frequency two-dimensional physical resource block;

Reconstruct the symbol sub-block into a sequence of modulation symbols.

A receiving device for implementing multiple access, comprising:

a basic physical resource block demapping module, configured to demap a symbol orthogonal transform extension sequence mapped to a time-frequency two-dimensional physical resource block corresponding to the basic physical resource block from a superposed signal of the basic physical resource block; An orthogonal transform despreading module, configured to despread the symbol orthogonal transform spreading sequence to obtain a symbol subblock corresponding to each time-frequency two-dimensional physical resource block;

a symbol sub-block demapping module, configured to demap each symbol sub-block according to a mapping relationship between the symbol sub-block and the time-frequency two-dimensional physical resource block;

A reassembly module, configured to reassemble symbol sub-blocks into a sequence of modulation symbols.

A multiple access system includes: a transmitting device for implementing multiple access and a receiving device for implementing multiple access according to an embodiment of the present invention.

It can be seen from the foregoing technical solutions that the multiple access access technical solution provided by the embodiments of the present invention combines the orthogonal transform extension technology with the OFDMA technology, and divides the sequence of the modulation symbol to be transmitted into a time-frequency two-dimensional physics with a length less than or equal to The symbol sub-block of the number of modulation symbols that can be carried by the resource block realizes that the anti-interference ability of the orthogonal transform extension can be fully utilized to improve the frequency band utilization of the cell edge, and the orthogonal multiple transform can be used to expand the flexible multiple access capability. Realizing the multiplexing of time-frequency resources can also effectively utilize the anti-multipath interference capability, flexible frequency domain scheduling capability and discrete frequency diversity gain of OFDMA technology in broadband transmission. DRAWINGS

Fig. 1 shows a specific example of allocation and use of channel resources in the existing OFDM modulation scheme. FIG. 2 shows a schematic structural diagram of a physical resource block in the prior art.

Fig. 3 is a schematic diagram showing the principle of modulation processing of data to be transmitted using the BR-OFDMA method.

FIG. 4 is a schematic diagram showing the structure of a unit user resource allocation of a single user in the existing BR-OFDMA modulation mode.

FIG. 5 is a schematic diagram showing the structure of unit block resource allocation of two users in the existing BR-OFDMA modulation mode.

FIG. 6 is a schematic flowchart diagram of a multiple access transmission method in an embodiment of the present invention.

FIG. 7 is a schematic structural diagram of a transmitting apparatus for implementing multiple access in an embodiment of the present invention.

FIG. 8 is a block diagram showing a preferred configuration of a transmitting apparatus for processing a plurality of modulated symbol streams to be transmitted in an embodiment of the present invention.

FIG. 9 is a diagram showing an example of resource mapping by a symbol sub-block mapping module according to an embodiment of the present invention.

FIG. 10 is a multiple access connection scheme for five users according to the multiple access transmission scheme provided by the embodiment of the present invention. An example of a resource mapping into the input.

FIG. 11 is a schematic flowchart diagram of a multiple access receiving method according to an embodiment of the present invention.

FIG. 12 is a schematic structural diagram of a receiving apparatus for implementing multiple access in an embodiment of the present invention. BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be further described in detail below with reference to the drawings and embodiments. A multiple access access technical solution is disclosed in the embodiment of the present invention, including: a multiple access access transmitting method and apparatus, a multiple access receiving method and apparatus. The multiple access access technical solution provided by the embodiment of the present invention combines the orthogonal transform extension technology with the OFDMA technology, and divides the sequence of the modulation symbol to be transmitted into a time-frequency two-dimensional physical resource block that is less than or equal to the length. The symbol sub-block of the number of modulation symbols can realize the use of the anti-interference ability of the orthogonal transform extension to improve the frequency band utilization of the cell edge, and can realize the complex of the time-frequency resource by using the orthogonal transform to expand the flexible multiple access capability. It can also effectively utilize the anti-multipath interference capability, flexible frequency domain scheduling capability and discrete frequency diversity gain of OFDMA technology in wideband transmission. FIG. 6 is a schematic flowchart diagram of a multiple access transmission method in an embodiment of the present invention. Referring to FIG. 6, the method includes the following steps: Step 601: Divide a sequence of modulation symbols into symbol sub-blocks, where the length of the symbol sub-blocks is less than or equal to the number of modulation symbols that can be carried by the time-frequency two-dimensional physical resource block.

Step 602: Determine a mapping relationship between the symbol sub-block, the time-frequency two-dimensional physical resource block, and the basic physical resource block.

Step 603: Perform symbol orthogonal sub-blocks that are in a mapping relationship with the same time-frequency two-dimensional physical resource block, and perform orthogonal transform expansion using mutually orthogonal spreading sequences to obtain a symbol orthogonal transform spreading sequence of each symbol sub-block.

Step 604: Superimpose the symbol orthogonal transform spreading sequence of the symbol sub-block having the mapping relationship with the same time-frequency two-dimensional physical resource block to obtain a superimposed signal, and map the superimposed signal to the corresponding basic physical resource block. After mapping the symbol orthogonal transform extended sequence overlay onto the corresponding basic physical resource block, The signals on the basic physical resource blocks are subjected to subsequent processing in accordance with the related methods in the prior art, which is not limited in the present invention. For example, the final transmitted signal can be transmitted through serial/parallel conversion and OFDM modulation. In the above step 601, the length of the symbol sub-block is one-nth of the number of modulation symbols that the time-frequency two-dimensional physical resource block can carry, where n is an integer greater than or equal to 1. Here, the length of the symbol sub-block is the number of modulation symbols included in the symbol sub-block. That is to say, when dividing the sequence of modulation symbols to be transmitted, the sequence of modulation symbols to be transmitted may be divided into symbol sub-blocks of the same length according to actual application requirements, or the sequence of modulation symbols to be transmitted may be divided into symbols of different lengths. Piece. In the existing BR-OFDMA technology, the length of the block can only be equal to the number of modulation symbols that can be carried by the time-frequency two-dimensional physical resource block.

Further, the mapping between the spreading factor and the symbol sub-block may also be set, and the different symbol sub-blocks are orthogonally transformed and extended using different spreading factors to obtain flexible multiple access capability.

In the foregoing step 602, before determining the mapping relationship between the symbol sub-block, the time-frequency two-dimensional physical resource block, and the basic physical resource block, the correspondence between the set expansion factor and the symbol sub-block, and each symbol sub-block may be further determined according to the mapping relationship between the symbol sub-block, the time-frequency two-dimensional physical resource block, and the basic physical resource block. The length, the number of modulation symbols that the time-frequency two-dimensional physical resource block can carry, and the number of modulation symbols that the basic physical resource block can carry, determine the number of basic physical resource blocks that each symbol sub-block needs to occupy. The formula for calculating the number of blocks of the time-frequency two-dimensional physical resource block that each symbol sub-block needs to occupy is:

(length of symbol sub-block X expansion factor) / number of modulation symbols that can be carried by a time-frequency two-dimensional physical resource block The formula for calculating the number of basic physical resource blocks that each symbol sub-block needs to occupy is:

(length of the symbol sub-block X expansion factor) / the number of modulation symbols that the basic physical resource block can carry and when determining the mapping relationship between the symbol sub-block, the time-frequency two-dimensional physical resource block, and the basic physical resource block, Each symbol sub-block determined needs to occupy the number of blocks of the time-frequency two-dimensional physical resource block, and each symbol sub-block is mapped to a continuous, corresponding block number of time-frequency two-dimensional physical resource blocks; according to each determined The time-frequency two-dimensional physical resource block needs to occupy the number of basic physical resource blocks, and each time-frequency two-dimensional physical resource block is mapped to a continuous, corresponding block number of physical resource blocks. Therefore, the orthogonal transform extension in step 603 is performed on the local time-frequency resource to ensure orthogonality between the symbol orthogonal transform spreading sequences superimposed on the same time-frequency two-dimensional physical resource block. When determining the mapping relationship between the symbol sub-block and the time-frequency two-dimensional physical resource block, different symbol sub-blocks of the same user or symbol sub-blocks of different users may be mapped to the same time-frequency two-dimensional physical resource block, and therefore, step 603 The symbol sub-blocks that are in a mapping relationship with the same time-frequency two-dimensional physical resource block as described in step 604 may be different symbol sub-blocks of the same user, or may be symbol sub-blocks of different users.

In the above step 603, the Walsh sequence may be used for orthogonal transform extension, or other orthogonal transform extension sequences such as Hadamard sequence, CAZAC sequence, and wavelet sequence may be used.

In the above step 604, when the symbol orthogonal transform spreading sequence of the symbol sub-block having the mapping relationship with the same time-frequency two-dimensional physical resource block is superimposed, the pilot symbol corresponding to the time-frequency two-dimensional physical resource block may be further further Superimposed on this basic physical resource block. Here, the pilot symbol can also be treated as a sequence of modulation symbols to be transmitted, divided into symbol sub-blocks, and subjected to orthogonal transform extension and then superimposed on the corresponding time-frequency two-dimensional physical resource block. It is of course possible to insert pilot symbols in a time-frequency two-dimensional physical resource block according to other methods in the prior art, which is not limited in the present invention. If the pilot symbol is also superimposed on the time-frequency two-dimensional physical resource block by orthogonal transform extension, when despreading is performed at the receiving end, the amplitude and phase estimation are performed according to the despread signal of the extended sequence in which the pilot is located. In the foregoing step 604, after the superimposed signal is obtained, before the superimposed signal is mapped to the corresponding basic physical resource block, the mapping of the superimposed signal to the basic physical resource block may be performed in different manners for different basic physical resource blocks, that is, The superposed signals corresponding to different basic physical resource blocks are each mapped to corresponding basic physical resource blocks in different manners. For example, a frequency domain mapping is used for some basic physical resource blocks, a time domain mapping is used for some basic physical resource blocks, and a time-frequency two-dimensional mapping is used for some basic physical resource blocks. Preferably, the obtained superposed signal may be first processed by interleaving and/or discrete Fourier transform (DFT-Spreading), and then mapped to corresponding basic physical resource blocks. The multiple access transmission method provided by the embodiment of the present invention is described in detail below through a specific example. As described above, in the OFDMA modulation scheme, a channel resource is a time-frequency two-dimensional structure, in which continuous sub-carriers and the N _f N _t OFDM symbols become time-frequency resource block is defined two-dimensional physical resource blocks in the frequency, The length of the time-frequency two-dimensional physical resource block is N = N _t x N _f . Assume that the sequence of modulation symbols obtained after channel coding and symbol modulation is:

Wherein each S represents a modulation symbol. In the above step 601, the modulation symbol sequence (1) is divided, and the Q symbol sub-blocks as shown in (2) are obtained:

^Ι' - ^η, \ (s _{n +} i, ...,S _n |8 _{ηι +} ... _+η .— _{ι +1} ,...,5 _{ηι +} ... _+η . ( 2 Wherein the length _ni and n ₂ n _{Q of} each symbol sub-block are respectively n-th of the length N of the time-frequency two-dimensional physical resource block, and n is an integer greater than or equal to 1. In the above step 602, it is determined. Preferably, each symbol sub-block can be separately mapped to a continuous basic physical resource block. Here, one time is set. The frequency two-dimensional physical resource block is mapped onto a basic physical resource block. Assume that the expansion factor of the qth symbol sub-block is Kq:

(where Kq,f is the frequency domain extension, therefore, Kq, _{t is the} time domain spreading factor) Then the qth symbol sub-block needs to occupy the number of blocks of the time-frequency two-dimensional physical resource block, that is, the number of basic physical resource blocks. for:

n _q X _q ,fx K _{3⁄4t ( 3 )}

N _f x N _t

As described above, in practical applications, symbol sub-blocks of different lengths can be divided, and different spreading factors are set for each symbol sub-block. For example, suppose that the number of modulation symbols that a time-frequency two-dimensional physical resource block can carry is 100, and one time-frequency two-dimensional physical resource block corresponds to one basic physical resource block. A symbol sub-block of a user contains 25 modulation symbols, and the extension factor corresponding to the symbol sub-block is 4, then the symbol sub-block can be mapped to a basic physical resource block. Meanwhile, the number of modulation symbols included in the other symbol sub-blocks of the user may be 50, and the spreading factor corresponding to the other symbol sub-blocks may be 4, then the other symbol sub-blocks need to occupy 2 basic physical resource blocks, and That is, the other symbol sub-blocks will be mapped onto two basic physical resource blocks. It is of course also possible to set a spreading factor of other values for a symbol sub-block having a modulation symbol number of 50. For example, if the spreading factor is 2, then the symbol sub-block needs to occupy one basic physical resource block. Corresponding to the BR-OFDMA technology, each unit block will contain 100 modulation symbols, and the number of repetitions is several. After repeated weighting, several hundred modulation symbols are obtained and mapped to several time-frequency two-dimensional physical resource blocks. on. In the embodiment of the present invention, the mapping between the length of the symbol sub-block, the symbol sub-block, the time-frequency two-dimensional physical resource block, and the basic physical resource block, the orthogonal transform extension sequence, and the like may be specified by using a scheduling algorithm.

In the above step 603, for a modulation symbol in each symbol sub-block that has a mapping relationship with the same time-frequency two-dimensional physical resource block, orthogonal transform extension may be performed using a set of orthogonal transform sequence groups, respectively. For example, for the qth symbol sub-block, whose expansion factor is Kq, a set of positives of length Kq can be used to represent:

Wherein, the superscript k _q represents the sequence number of the orthogonal transform sequence in the orthogonal transform sequence group. After multiplying the modulation symbol in the qth symbol sub-block by the orthogonal transform sequence of (4), the symbol orthogonal transform spreading sequence of the qth symbol sub-block is obtained:

The superscript k _q in the middle represents the sequence number of the orthogonal transform sequence in the orthogonal transform sequence group, and the subscript q represents the symbol sub-block number. The superscript _kq in C, _q + represents the sequence number of the orthogonal transform sequence in the orthogonal transform sequence group, the subscript n represents the sequence number of the modulation symbol in the qth sub-block, represents the spreading factor, and m represents the modulation symbol is orthogonal. The sequence number in the extended sequence after the extension is transformed. After step 603, a symbol orthogonal transform spreading sequence corresponding to each symbol sub-block is obtained. In step 604, orthogonal transform extension sequences of each symbol sub-block having a mapping relationship with the same time-frequency two-dimensional physical resource block are superimposed. Here, the orthogonal transform extension sequence to be superimposed may be an orthogonal transform extension sequence corresponding to different symbol sub-blocks of the same user, or may be an orthogonal transform extension sequence corresponding to symbol sub-blocks of different users, and different orthogonal transform extensions. Sequences can distinguish between different symbol sub-blocks. As described above, the superimposed signals obtained after the superposition can be mapped to the corresponding basic physical resource blocks by using different mapping manners. In order to obtain the diversity gain more fully, the superposed signals for the symbol orthogonal transform spreading sequence may be interleaved first and then mapped to the corresponding basic physical resource blocks. Since the signal after the orthogonal transform is scrambled by the discrete Fourier transform (DFT- Spreading) transform, the phase of the modulation symbol mapped to the OFDM physical resource block will be Machine, thereby suppressing the peak-to-average ratio (PAPR) problem in OFDM transmission. Therefore, for the symbol orthogonal transform extended sequence superposition signal, the discrete Fourier extension may also be performed first, and then mapped to the corresponding basic physical resource block. As described above, after the symbol orthogonal transform extended sequence is superimposed and mapped onto the corresponding basic physical resource block, the signal on the basic physical resource block may be subsequently processed according to the related method in the prior art, and the present invention does not limit. For example, the final transmitted signal can be transmitted through serial/parallel conversion and OFDM modulation.

Corresponding to the foregoing multiple access transmission method, in the embodiment of the present invention, a transmitting device for implementing multiple access is provided, and a schematic structural diagram of the device is shown in FIG. 7. Referring to FIG. 7, a transmitting apparatus for implementing multiple access according to the present invention includes: a splitting module 710, a symbol sub-block mapping module 720, an orthogonal transform extension module 730, a basic physical resource block mapping module 740, a serial/parallel conversion module 750, and OFDM. The modulating module 760 is configured to divide the to-be-transmitted modulation symbol into symbol sub-blocks, where the length of the symbol sub-block is less than or equal to the number of modulation symbols that can be carried by the time-frequency two-dimensional physical resource block. The mapping module 720 is configured to determine a mapping relationship between the symbol sub-block, the time-frequency two-dimensional physical resource block, and the basic physical resource block. The orthogonal transform expansion module 730 is configured to map the same time-frequency two-dimensional physical resource block. The symbol orthogonal transform extension sequence of the symbol symbol sub-block of the relationship is sent to the basic physical resource block mapping module 730. The basic physical resource block mapping module 740 is configured to use the symbol sub-block that has a mapping relationship with the same time-frequency two-dimensional physical resource block. The symbol orthogonal transform extended sequence superposition to obtain a superimposed signal, and the superimposed signal is mapped to a corresponding basic physical resource block The serial / parallel conversion module 750, a basic physical resource block signal serial / parallel conversion.

The OFDM modulation module 760 is configured to perform OFDM modulation on the serial/parallel converted signal to obtain a transmitted signal.

The symbol sub-block mapping module 720 shown in FIG. 7 may include: a block number determining unit and a mapping unit. The block number determining unit is configured to perform, according to the set expansion factor and the symbol sub-block, each The length of the symbol sub-block, the number of modulation symbols that the time-frequency two-dimensional physical resource block can carry, and the number of modulation symbols that can be carried by the basic physical resource block, determining that each symbol sub-block needs to occupy the time-frequency two-dimensional physical resource block The number of blocks, and the number of blocks of basic physical resource blocks that each time-frequency two-dimensional physical resource block occupies; a mapping unit, a block for occupying a time-frequency two-dimensional physical resource block according to each determined symbol sub-block Number, each symbol sub-block is mapped to a continuous, corresponding block number of time-frequency two-dimensional physical resource blocks, according to the determined number of blocks of the basic physical resource block occupied by each time-frequency two-dimensional physical resource block, Each time-frequency two-dimensional physical resource block is mapped to a continuous, corresponding block number of basic physical resource blocks. The basic physical resource block mapping module 740 shown in FIG. 7 may further include an interleaving unit for interleaving the superposed signals and then mapping to the corresponding basic physical resource blocks. The basic physical resource block mapping module 740 shown in FIG. 7 may further include a discrete Fourier expansion module for performing discrete Fourier expansion on the superposed signal and then mapping to the corresponding basic physical resource block. In practical applications, there are usually a plurality of users to transmit modulation symbols, that is, there are multiple channels of modulated modulation symbols to be transmitted, and FIG. 8 shows a transmitting apparatus for processing multiple streams of modulated symbol streams to be transmitted in the embodiment of the present invention. A schematic diagram of a preferred composition. Referring to FIG. 8, the k segmentation modules 710 are configured to perform segmentation processing on the k-channel modulation symbol streams to be transmitted, and send the symbol-subblocks obtained by the segmentation process to the symbol sub-block mapping module 720. The symbol sub-block mapping module 720 is configured to perform mapping between the symbol sub-block, the time-frequency two-dimensional physical resource block, and the basic physical resource block, and is configured to send the symbol sub-block obtained after the mapping to the multiple orthogonal transform expansion module 730. . Here, symbol sub-blocks that have a mapping relationship with the same time-frequency two-dimensional physical resource block will be sent to the same orthogonal transform extension module 730. The plurality of orthogonal transform extension modules 730 are configured to send a symbol orthogonal transform spreading sequence with a mapping time subblock to the same time-frequency two-dimensional physical resource block, and send the same to the corresponding scrambling module 810; the scrambling module 810 is used to The received symbol orthogonal transform spreading sequence is scrambled to suppress and cancel interference between cells, and the scrambled processed signal is sent to the corresponding interleaving unit 820. The interleaving unit 820 is configured to interleave the signal from the scrambling module 810 to obtain sufficient diversity gain and enhanced descrambling performance, and send the interleaved signal to the corresponding serial/parallel conversion module 750, by string/ The parallel conversion module 750 and the OFDM modulation module continue with the subsequent processing. The above disturbance Both code and interleaving are performed in units of basic physical resource blocks. FIG. 9 is a diagram showing an example of resource mapping by a symbol sub-block mapping module according to an embodiment of the present invention. Referring to FIG. 9, a time-frequency two-dimensional physical resource block spans 24 consecutive subcarriers in a frequency domain and spans 8 consecutive OFDM symbols in a time domain, and the time-frequency two-dimensional physical resource block may include several Basic physical resource block. In the figure, the region of the orthogonal transform extension sequence direction occupying the same time-frequency resource represents a symbol sub-block mapped to the same time-frequency two-dimensional physical resource block, for example, as shown in the figure, cf ² ₂ ),

The address mode shares the same time-frequency two-dimensional physical resource block, and the spreading factor is 4.

FIG. 10 is a diagram showing an example of resource mapping for multiple users accessing multiple users using the multiple access transmission scheme provided by the embodiment of the present invention. In the example shown in Fig. 10, the symbol sub-blocks of the five users are respectively shown in a rectangular parallelepiped of different patterns. The orthogonal transform extended sequence axis includes three layers, which indicates that each set of orthogonal transform extended sequence groups contains three mutually orthogonal transform spreading sequences. That is to say, the symbol orthogonal transform spreading sequence corresponding to three different symbol sub-blocks can be superimposed in the same time-frequency two-dimensional physical resource block by multiple access. The three different symbol sub-blocks may be symbol sub-blocks of different users, or may be different symbol sub-blocks of the same user. Each layer shown in Figure 9 contains 6x5 = 30 cuboids, indicating that the time-frequency resources shown in Figure 10 contain 30 time-frequency two-dimensional physical resource blocks.

The advantages of the multiple access scheme of the embodiment of the present invention can be clearly observed from FIG. 10:

1) because each of the symbol sub-blocks is separately mapped to a continuous basic physical resource block when determining a mapping relationship between the symbol sub-block, the time-frequency two-dimensional physical resource block, and the basic physical resource block, The orthogonal transform extension is performed on a local basic physical resource block. Since the channel response on the local basic physical resource block is substantially flat, the orthogonality between the symbol orthogonal transform spreading sequences of different symbol sub-blocks that have a mapping relationship with the same basic physical resource block is ensured, and the multi-user is eliminated. Interference, avoiding the use of complex joint detection receivers.

2) Mapping the symbol sub-blocks of the same user onto discrete basic physical resource blocks to ensure sufficient frequency diversity gain in wideband transmission.

3) The orthogonal transform spreading sequences corresponding to the different time-frequency two-dimensional physical resource blocks are independent of each other, and therefore, the orthogonal transform spreading factor on each basic physical resource block can be flexibly adjusted.

4) The granularity of the orthogonal transform extension is a symbol sub-block, and the symbol sub-block can be divided into n-th of the time-frequency two-dimensional physical resource block, so that flexible scheduling can be realized. For example, the symbol sub-block lengths of the same user may be different, and the number of orthogonal transform spreading sequences occupied by the user on the same time-frequency two-dimensional physical resource block The multiple access access transmission scheme provided by the embodiment of the present invention is described in detail above. The specific implementation manner of the multiple access access receiving scheme in the embodiment of the present invention is described below.

FIG. 11 is a schematic flowchart diagram of a multiple access receiving method according to an embodiment of the present invention. Referring to Figure 11, the method includes:

Step 1101: Demap the symbol orthogonal transform spreading sequence mapped to the time-frequency two-dimensional physical resource block corresponding to the basic physical resource block from the superposed signal of the basic physical resource block.

Step 1102: De-spread the symbol orthogonal transform spreading sequence to obtain a symbol sub-block corresponding to each time-frequency two-dimensional physical resource block.

Step 1103: Demap each symbol sub-block according to a mapping relationship between the symbol sub-block and the time-frequency two-dimensional physical resource block.

Step 1104: Reassemble the symbol sub-block into a sequence of modulation symbols.

Before the above step 1101, the received signal may be subjected to OFDM demodulation, frequency domain equalization, and parallel/serial conversion processing according to the prior art to obtain a superimposed signal before OFDM modulation. If the signal is interleaved and/or discrete Fourier-expanded at the transmitting end, the corresponding de-interleaving and/or de-discrete Fourier expansion processing of the symbol orthogonal transform spreading sequence is also required at the receiving end.

When de-mapping in the above step 1101, the demapping needs to be performed in the order of the basic physical resource block mapping of the transmitting end. When the modulation symbol sequence is recombined in step 1104, it should also be in the same order as the transmitting-end symbol sub-block to the basic physical resource block. Complete the reorganization. The modulation symbol sequence obtained by the above multiple access receiving method can be used for subsequent channel decoding processing, which is not limited in the present invention.

FIG. 12 is a schematic structural diagram of a receiving apparatus for implementing multiple access in an embodiment of the present invention. Referring to FIG. 12, the apparatus includes: an OFDM demodulation module 1210, a frequency domain equalization module 1220, a parallel/serial conversion module 1230, a basic physical resource block demapping module 1240, an orthogonal transform despreading module 1250, and a symbol subblock demapping module. 1260 and reassembly module 1270.

The OFDM demodulation module 1210, the frequency domain equalization module 1220, and the parallel/serial conversion module 1230 are respectively configured to perform OFDM demodulation, frequency domain equalization, and parallel/serial conversion on the received signal.

The basic physical resource block demapping module 1240 is configured to demap the symbol orthogonal transform extension sequence mapped to the time-frequency two-dimensional physical resource block corresponding to the basic physical resource block from the superposed signal of the basic physical resource block;

An orthogonal transform despreading module 1250 is configured to despread the symbol orthogonal transform extended sequence to obtain a pair a symbol sub-block of a two-dimensional physical resource block at each time-frequency;

a symbol sub-block demapping module 1260, configured to demap each symbol sub-block according to a mapping relationship between the symbol sub-block and the time-frequency two-dimensional physical resource block;

The reassembly module 1270 is configured to reassemble the symbol sub-block into a sequence of modulation symbols.

If the signal is interleaved and/or discrete Fourier extended at the transmitting end, the deinterleaving module and/or the de-discrete Fourier expansion module are also required to be set at the receiving end, and the symbol orthogonal transform spreading sequence is deinterleaved accordingly. / or solve discrete Fourier expansion and other processing.

For example, if the signal is interleaved at the transmitting end, a deinterleaving module needs to be provided at the receiving end for deinterleaving the symbol orthogonal transform spreading sequence output by the basic physical resource block demapping module 1240, and deinterleaving The resulting symbol orthogonal transform spreading sequence is sent to an orthogonal transform despreading module 1250.

If the signal is subjected to discrete Fourier expansion processing on the transmitting end, a de-discrete Fourier expansion module is needed to perform de-discrete Fourier expansion on the symbol orthogonal transform spreading sequence output by the basic physical resource block demapping module 1240. The symbol orthogonal transform spreading sequence obtained by solving the discrete Fourier extension is sent to the orthogonal transform despreading module 1250.

The present invention also provides a multiple access system, including: a transmitting device for implementing multiple access and a receiving device for implementing multiple access according to an embodiment of the present invention.

It can be seen from the foregoing technical solutions that the multiple access access technical solution provided by the embodiments of the present invention can fully utilize the anti-interference capability extended by the orthogonal transform, solve the interference problem of the cell edge user, and significantly increase the transmission rate and spectrum utilization efficiency of the edge user. . Moreover, the soft capacity characteristic extended by the orthogonal transform can be utilized to reduce the resource allocation overhead of a small amount of data transmission in a burst, especially the uplink signaling transmission overhead. Moreover, since the orthogonal transform extension in the multiple access technology provided by the embodiment of the present invention is performed on a time-frequency two-dimensional physical resource block (local time-frequency resource), the positive transform extension signal is guaranteed to be positive. Interoperability, avoid using complex joint detection receivers at the receiving end. In addition, symbol sub-blocks of the same user are mapped onto discrete basic physical resource blocks, enabling flexible scheduling and sufficient frequency diversity gain in wideband transmission.

It can be understood that those skilled in the art can understand that all or part of the process of implementing the above embodiments can be completed by a program to instruct related hardware, and the program can be stored in a computer readable storage medium. Wherein, the program, when executed, may include the flow of an embodiment of the methods as described above. The storage medium may be a magnetic disk, an optical disk, or a read-only storage memory (Read-Only) Memory, ROM) or random access memory (RAM). The spirit and scope of the Ming. Thus, it is intended that the present invention cover the modifications and the modifications of the invention

Claims

Rights request

A multiple access transmission method, comprising:

Separating the sequence of modulation symbols to be transmitted into symbol sub-blocks, where the length of the symbol sub-blocks is less than or equal to the number of modulation symbols that can be carried by the time-frequency two-dimensional physical resource block;

2. The method according to claim 1, wherein the length of the symbol sub-block is one-nth of the length of the time-frequency two-dimensional physical resource block, and n is an integer greater than or equal to 1.

The method according to claim 1, wherein before the determining the mapping relationship between the symbol sub-block, the time-frequency two-dimensional physical resource block, and the basic physical resource block, the method further includes: according to the set expansion factor Corresponding relationship with the symbol sub-block, the length of each symbol sub-block, the number of modulation symbols that the time-frequency two-dimensional physical resource block can carry, and the number of modulation symbols that the basic physical resource block can carry, determining that each symbol sub-block needs The number of blocks of the time-frequency two-dimensional physical resource block and the number of blocks of the basic physical resource block that each time-frequency two-dimensional physical resource block needs to occupy;

The mapping relationship between the determined symbol sub-block, the time-frequency two-dimensional physical resource block, and the physical resource block is: according to the determined number of blocks of the time-frequency two-dimensional physical resource block that each symbol sub-block needs to occupy, Each symbol sub-block is mapped to a continuous, corresponding block number of time-frequency two-dimensional physical resource blocks; according to the determined time-frequency two-dimensional physical resource block, the number of basic physical resource blocks to be occupied, each of The time-frequency two-dimensional physical resource block is mapped to consecutive, corresponding blocks of physical resource blocks.

The method according to claim 1, wherein the symbol sub-blocks having a mapping relationship with the same time-frequency two-dimensional physical resource block are: different symbol sub-blocks of the same user or symbol sub-blocks of different users.

The method according to claim 1, wherein when the symbol orthogonal transform extension sequence of the symbol sub-block having a mapping relationship with the same time-frequency two-dimensional physical resource block is superimposed, the method further includes: The pilot symbols corresponding to the time-frequency two-dimensional physical resource block are superimposed on the time-frequency two-dimensional physical resource block.

The method according to claim 1, wherein before the superimposing signal is mapped to the corresponding basic physical resource block, the method further includes:

The superimposed signals are interleaved and/or discrete Fourier extended.

7. The method according to claim 1, wherein the mapping the superimposed signal to the corresponding basic physical resource block is:

The superposed signals corresponding to different basic physical resource blocks are respectively mapped to corresponding basic physical resource blocks by using frequency domain mapping, time domain mapping or time-frequency domain two-dimensional mapping.

8. A transmitting device for implementing multiple access, characterized in that it comprises:

a basic physical resource block mapping module, configured to map the same time-frequency two-dimensional physical resource block The symbol orthogonal transform extended sequence of the symbol sub-block is superimposed to obtain a superimposed signal, and the superimposed signal is mapped onto the corresponding basic physical resource block.

The apparatus according to claim 8, wherein the symbol sub-block mapping module includes: a block number determining unit, configured to perform, according to a set relationship between a spreading factor and a symbol sub-block, each symbol sub-block The length, the number of modulation symbols that the time-frequency two-dimensional physical resource block can carry, and the number of modulation symbols that the basic physical resource block can carry, determine the number of blocks of the time-frequency two-dimensional physical resource block that each symbol sub-block needs to occupy, And the number of blocks of the basic physical resource block that each of the time-frequency two-dimensional physical resource blocks needs to occupy; the symbol sub-block mapping module further includes: a mapping unit, configured to be used according to each of the determined symbol sub-blocks The number of blocks of the time-frequency two-dimensional physical resource block, each symbol sub-block is mapped to a continuous, corresponding block number of time-frequency two-dimensional physical resource blocks, according to each of the determined time-frequency two-dimensional physical resource blocks The number of blocks of the basic physical resource block maps each time-frequency two-dimensional physical resource block to a continuous, corresponding block number of basic physical resource blocks.

The apparatus according to claim 8, wherein the basic physical resource block mapping module further comprises: an interleaving unit, configured to first interleave the superposed signal, and then map to a corresponding basic physical resource block. on.

The apparatus according to claim 8, wherein the basic physical resource block mapping module further comprises: a discrete Fourier expansion unit, configured to perform discrete Fourier expansion on the superposed signal, and then map to corresponding On the basic physical resource block.

12. A multiple access receiving method, comprising:

Despreading the symbol orthogonal transform spreading sequence to obtain a symbol sub-block corresponding to each time-frequency two-dimensional physical resource block; Decoding each symbol sub-block according to a mapping relationship between the symbol sub-block and the time-frequency two-dimensional physical resource block;

Reconstruct the symbol sub-block into a sequence of modulation symbols.

The method according to claim 12, before the despreading the symbol orthogonal transform spreading sequence, further comprising: performing deinterleaving and/or de-discrete Fourier extension on the symbol orthogonal transform spreading sequence .

A receiving device for implementing multiple access, characterized in that it comprises:

And a basic physical resource block demapping module, configured to demap the symbol orthogonal transform extension sequence mapped to the time-frequency two-dimensional physical resource block corresponding to the basic physical resource block from the superposed signal of the basic physical resource block;

An orthogonal transform despreading module, configured to despread the symbol orthogonal transform spreading sequence to obtain a symbol subblock corresponding to each time-frequency two-dimensional physical resource block;

The device according to claim 14, wherein the device further comprises: a deinterleaving module, configured to deinterleave a symbol orthogonal transform spreading sequence output by the basic physical resource block demapping module, And de-interleaving the symbol orthogonal transform spreading sequence to the orthogonal transform despreading module.

The device according to claim 14, wherein the device further comprises: a de-discrete Fourier expansion module, configured to solve a symbol orthogonal transform extension sequence output by the basic physical resource block demapping module Discrete Fourier extension, and the symbol orthogonal transform extension sequence obtained by solving the discrete Fourier extension is sent to the orthogonal transform despreading module.

A multiple access system, comprising: a transmitting device for implementing multiple access according to claim 8 and a receiving device for implementing multiple access according to claim 14.