WO2009067920A1

WO2009067920A1 - Method and device for transmitting or receiving data in multi-antenna system

Info

Publication number: WO2009067920A1
Application number: PCT/CN2008/073007
Authority: WO
Inventors: Sheng Liu; Yinwei Zhao
Original assignee: Huawei Technologies Co., Ltd.
Priority date: 2007-11-23
Filing date: 2008-11-11
Publication date: 2009-06-04
Also published as: CN101442389B; CN101442389A

Abstract

A data transmitting method for a multi-antenna system is provided, which includes: channel coding, interleaving and modulating processing to the data information sent to multi receiving end, in which the data information sent to each sink is interleaved by different interleaving patterns; and sending the modulated data information and the interleaving patterns used by the data information to the multi receiving end. A data receiving method and device for a multi-antenna system are provided.

Description

Data transmission and reception method and device for multi-antenna system

The present invention relates to the field of communications, and in particular, to a data transmission and reception method and apparatus for a multi-antenna system. Background technique

To enhance the performance of mobile communication systems, at 3G (the 3rd Generation Mobile)

Communication, 3rd Generation Mobile Communications) /4G (the 4th Generation Mobile)

MIMO (Multiple Input Multiple Output) technology is introduced in the multi-antenna digital communication system of Communication, 4th Generation Mobile Communication. The MIMO technology refers to using a plurality of transmitting antennas and receiving antennas at the transmitting end and the receiving end, respectively, and transmitting and receiving signals through multiple antennas at the transmitting end and the receiving end, thereby improving data transmission rate and/or bit error rate. The transmitting antenna used in the MIMO technology may be a physical antenna or a virtual antenna. In 3GPP TR 25.876 V1.7.1, a virtual antenna technology is proposed, which provides multiple virtual antenna ports. After multiple transmit signals are sent to multiple virtual antenna ports respectively, the transmitted signal vectors are multiplied by one. Or multiple matrices, and then sent to each physical antenna port for transmission. The MIMO system includes a SU-MIMO (Single User MIMO) system and a MU-MIMO (Multiple User-Multiple Input Multiple Output) system, and the SU-MIMO system refers to multiple single transmitters. A system for transmitting and receiving signals between an antenna and a plurality of antennas at a single receiving end. A MU-MIMO system refers to a system that transmits and receives signals between multiple antennas of a single (or multiple) transmitting ends and multiple antennas of multiple receiving ends. The multiple antennas at the transmitting end of the MU-MIMO system may be different polarization directions of one antenna or different beams and the like. As described above, the MU-MIMO system not only refers to a system in which one transmitting end (such as a base station) communicates with multiple receiving ends (such as multiple mobile terminals, multiple relay stations), but also includes multiple transmitting ends through coordinated communication with each other. A system in which a plurality of receiving ends communicate, for example, a MU-MIMO system formed between a plurality of cells and a plurality of users after coordinated communication between the base stations. Figure 1 shows a schematic diagram of a MU-MIMO. The figure shows one sender and two receivers (user #1 and user #2). The data signal at the transmitting end is transmitted to the user #1 and the user #2 on the same time-frequency resource through the antennas M1 and M2. As shown, User #1 receives signals through N1 and N2, and User #2 receives signals through N3 and N4. Specifically, the signal received by the user #1 includes not only the signal sent by the transmitting end to the user #1 but also the signal sent by the transmitting end to the user #2, and the interference is also called the multiple access Interference (MAI). Address interference). Similarly, the signal received by the user #2 includes not only the signal sent by the transmitting end to the user #2 but also the signal sent by the transmitting end to the user #1, and the signal between the user #1 and the user #2 is interfered. For MAI ( Multiple Access

Interference, multiple access interference). In the prior art, the receiving end user #1 and the user #2 notify the transmitting end of the state affected by the multiple access interference through the CSI (Channel Status Indicator) of the uplink channel, that is, the user C1 passes the uplink CSI. The sender end user #2 is notified of the MAI degree thereof, and the user #2 notifies the sender user #1 of the MAI degree thereof by its uplink CSI. At the same time, the receiving end user #1 and user #2 also feed back the quantized channel parameters to the transmitting end. After receiving the CSI and channel parameters sent by different users, the transmitting end uses preprocessing techniques such as beamforming, precoding or pre-filtering to achieve the purpose of reducing the MAI interference between the receiving end users, so that the receiving end user correctly decodes the transmitting end. The information sent to the user. In the prior art, the MU-MIMO system is well applied to the spatial multiplexing technology, and the capacity of the wireless communication system is greatly improved. The signal transmitted to multiple users is first performed at the transmitting end of the MU-MIMO system. Pre-processing (pre-coding, pre-filtering, etc.) to suppress or eliminate the MAI and ISI (Inter-Symbol Interference) at the receiving end Interference). However, in the actual system, since the CSI and the channel response parameters are both quantized and fed back to the transmitting end, the transmitting end performs preprocessing according to the feedback information. Due to the limitation of the number of feedback information and the existence of quantization error, the MAI and ISI are inevitably present at the receiving end, so the system performance of the existing MU-MIMO system still has room for further improvement. Summary of the invention

In view of this, embodiments of the present invention provide a data transmission and reception method and apparatus for a multi-antenna system. It can improve the signal-to-noise ratio of the signal received at the receiving end of the multi-antenna system and improve the performance of the system.

Specifically, the data sending method of the multiple input multiple output system provided by the embodiment of the present invention includes: performing channel coding, interleaving, and modulation processing on data information sent to multiple receiving ends, where the data information sent to each receiving end is performed. Interleaving using different interleaving patterns;

And transmitting the modulated data information and the interleaved pattern information used by the data information to the plurality of receiving ends.

Correspondingly, the data transmitting apparatus of the MIMO system according to the embodiment of the present invention includes: a coding unit, configured to perform channel coding processing on data information sent to multiple receiving ends; and an interleaving unit, configured to The encoded data information is interleaved, and the data information sent to each receiving end is interleaved by using different interleaving patterns;

a modulating unit, configured to perform modulation processing on the data information after the interleaving process;

And a sending unit, configured to send the data information after the modulation processing and the interlaced pattern information used by the data information to the plurality of receiving ends.

Correspondingly, the data receiving method of the multiple input multiple output system provided by the embodiment of the present invention includes: receiving data information sent to multiple receiving ends and interleaving pattern information used by the data information; Performing basic signal detection, deinterleaving, and channel decoding processing on the received data information to obtain data information after the channel decoding process, and the pattern used by the deinterleaving is determined by the received interleaving pattern information. .

Correspondingly, the data receiving apparatus of the MIMO system according to the embodiment of the present invention includes: a receiving unit, configured to receive data information sent to multiple receiving ends and interleaving pattern information used by the data information;

a basic signal detecting unit, configured to perform basic signal detecting processing on the data information received by the receiving unit;

a deinterleaving unit, configured to perform deinterleaving processing on data information after performing basic signal detection processing on the basic signal detecting unit, where a pattern used by the deinterleaving is determined by the interleaving pattern information; The data information after deinterleaving by the deinterleaving unit performs channel decoding processing; and the obtaining unit is configured to obtain data information after decoding processing by the decoding unit.

In the embodiment of the present invention, the data information sent to the multiple receiving ends is separately interleaved and different interleaving patterns are used at the transmitting end, and the order of the original coding sequence is disturbed, so that adjacent chips are approximated irrelevant, so that chips and chips are made. The detection of multiple receiving signals between them becomes easier; the received data is iterated by multiple loops at the receiving end, effectively improving the signal to interference and noise ratio of the received signal, reducing the bit error rate and bit error rate, effectively Improved performance of multiple input multiple output systems. DRAWINGS

1 is a schematic diagram of a conventional MU-MIMO system for transmitting and receiving data; FIG. 2 is a schematic structural diagram of an embodiment of a MU-MIMO system of the present invention;

3 is a schematic flow chart of an embodiment of a data transmission method of the MU-MIMO system of the present invention; FIG. 4 is a schematic flowchart of an embodiment of a data receiving method of the MU-MIMO system of the present invention; 5 is a schematic diagram of an embodiment of a data transmission scheme of a MU-MIMO system according to the present invention; FIG. 6 is a schematic diagram of an embodiment of a data receiving scheme of a MU-MIMO system of the present invention; FIG. 7 is a MU- FIG. 8 is a schematic diagram of an embodiment of a data transmission scheme of an OFDMA MU-MIMO system based on the IEEE 802.16e protocol;

9 is a schematic diagram of an embodiment of a data receiving scheme of an OFDMA MU-MIMO system based on the IEEE 802.16e protocol. detailed description

The present invention will be further described in detail below with reference to the accompanying drawings.

The embodiment of the invention provides a data transmission technology of a multi-antenna system, which improves the channel decoding performance of the receiving end by improving the SINR (Signal Interference Noise Ratio) of the received signal, thereby further improving the multi-antenna system. Capacity, reduce bit error rate and bit error rate, and achieve the purpose of effectively improving system performance.

The basic process of data transmission and corresponding data receiving in the multi-antenna system provided by the embodiment of the present invention includes: performing channel coding on the data information sent to multiple receiving ends at the transmitting end of the multi-antenna system, and interleaving by using different interleaving patterns after encoding. Then, respectively, the separately modulated data symbols are sent by the antenna to the channel; and the interleaving pattern respectively adopted by the transmitting end to the receiving end for data interleaving is notified by the control signaling. At the receiving end, basic signal detection is first performed on the received multiple signals to suppress or eliminate ISI and channel environment interference; and then at least two sets of signal information obtained after the basic signal detection are performed according to the interleaving pattern indicated by the control signaling. Deinterleaving and channel decoding to obtain an estimated value of the multipath signal data; to obtain high quality data estimation values, respectively, the estimated values are interleaved Iteratively input values for the second basic signal detection to eliminate or suppress interference of other road signal information from each of the signal information. After repeated iterations of the loop, until the number of loop iterations reaches the preset maximum number of loops, or the data information decoded by the decoder passes the CRC (Cyclic Redundancy Check) check detection. After repeated loop iteration processing, the interference of other road signal information in each channel information can be completely eliminated, thereby improving the signal to interference and noise ratio of the received signal and improving the channel decoding performance of the receiving end. The MU-MIMO system in the multi-antenna system will be described in detail below as an example. The transmitting end of the MU-MIMO system in the embodiment of the present invention includes a base station, a relay station, and the like, and the receiving end includes a mobile terminal, a relay station, a PC softphone, and a fixed terminal. 2 is a schematic structural diagram of an embodiment of a MU-MIMO system according to the present invention; as shown in FIG. 2, in this embodiment, the transmitting apparatus 10 includes a coding unit 101, a spreading unit 102, an interleaving unit 103, a modulation unit 104, and a pre- Processing unit 105 and transmitting unit 106, wherein

The encoding unit 101 is configured to perform channel coding processing on data information sent to multiple receiving ends;

The spreading unit 102 is configured to perform spectral processing on the channel information processed by the coding unit 101, and then transmit the data information to the interleaving unit 103, and use a spreading factor and a spreading code for the data information. And the offset parameter is sent to the sending unit 106. In a specific implementation, the sending device may not include the spreading unit. The coding unit and the spread spectrum unit constitute a low code rate encoder by which the code rate of the transmitted data is reduced. The interleaving unit 103 is configured to perform interleaving processing on the data information that is spread by the spreading unit 102, and the interleaving unit 103 performs interleaving processing on the data information of each receiving end by using different interleaving patterns. In specific implementation, the interleaving unit 103 may be a random interleaver, and different interleaving patterns are generated by different random seeds; the interleaving unit 103 may also be a block interleaver, a convolutional interleaver, or a truncated bit inversion interleaver. In general, the interlaced pattern is generated according to pre-defined rules, but the interlaced pattern can also After being generated by the sender, the receiver is notified in a specific manner. However, no matter which method is used to generate the interleaving pattern, the transmitting end needs to send the interleaving pattern information used for the data information of each receiving end to the plurality of receiving ends through control signaling. The interleaving process scrambles the order of the original code sequences, making the adjacent chips approximation-independent, making it easy for the receiver to detect chip-based multi-user data.

The modulating unit 104 is configured to perform modulation processing on the data information after the interleaving unit 103 is interleaved;

The pre-processing unit 105 is configured to perform pre-processing on the modulated data information of the modulation unit 104, and send the pre-processed pre-processing mode information to the sending unit 106. In a specific implementation, the pre-processing unit 105 includes one or more of a pre-coding processing unit, a pre-equalization processing unit, a pre-interference cancellation processing unit, a beamforming processing unit, and a space-time encoding processing unit. Specifically, the pre-coding processing unit The pre-processed data information is pre-processed by a pre-coding technique, and the pre-equalization processing unit pre-processes the modulated data information by using a pre-equalization technique, and the pre-interference cancellation processing unit is configured to pre-transmit the signal in the physical channel. Possible interference and noise are eliminated, the wave. In an actual system, each receiving end feeds back the CSI of the channel and the quantized channel parameters to the transmitting end. The pre-processing unit 105 at the transmitting end can perform corresponding pre-processing according to the feedback information. For example, the precoding matrix is obtained by using the channel parameter calculation at the receiving end, and the index information of the codeword used by the precoding is notified by the feedback information, and after receiving the index information, the transmitting end can select the corresponding precoding. Matrix parameters, precoding the data to be sent.

The sending unit 106 is configured to send the data information processed by the pre-processing unit 105 to the plurality of receiving ends, and use the interleaving pattern information used by the interleaving unit 103 for the data information of each receiving end. The spreading factor, the spreading code, and the offset parameter used by the spreading unit 102 for the data information of each receiving end, and the data information of each receiving end by the pre-processing unit 105 The pre-processing mode information is sent to the multiple receiving ends. In a specific implementation, the sending unit 106 includes multiple physical or virtual antennas. The relevant parameters used in the specific implementation of the spread spectrum can be pre-agreed by the transmitting end and the receiving end without being transmitted during the data transmission.

Correspondingly, the receiving end data receiving device 20 includes a receiving unit 201, a channel equalizing unit 202, a basic signal detecting unit 203, a deinterleaving unit 204, a decoding unit 205, an interleaving unit 206, an obtaining unit 207, and a loop control unit 208, where

The receiving unit 201 is configured to receive data information sent to the multiple receiving ends, and the interleaving pattern information used by the data information, and a spreading factor used when performing spreading processing on the data information sent to the multiple receiving ends, a spreading code and an offset parameter and pre-processing mode information for pre-processing the data information sent to the plurality of receiving ends. The relevant parameters used in the specific implementation of the spread spectrum can be pre-agreed by the transmitting end and the receiving end without receiving in the data transmission process.

The channel equalization unit 202 is configured to perform channel equalization processing on the data information received by the receiving unit 201. After using the channel equalization technology, the ISI and the MAI may be suppressed or eliminated to a certain extent, thereby further improving system performance. . In a specific implementation, the channel equalization unit 202 includes a Linear Minimum Mean-Squared Error (L-MMSE) equalization unit, a Zero-Forcing (ZF) equalization unit, and a Maximum Likelihood (ML) equalization. Unit, Serial Interference Cancellation (SIC) equalization unit, Parallel Interference Cancellation (PIC) equalization unit. In a specific implementation, the receiving device may also not include a channel equalization unit. In a specific implementation, when performing signal equalization on the received signal, combining with the pre-processing mode information sent by the transmitting end, calculating channel response parameters, CSI and other related parameters of the system, and then feeding back to the transmitting end through quantization, the transmitting end can be This information is further pre-processed accordingly.

The basic signal detecting unit 203 is configured to input data information received by the receiving unit 201. Line basic signal detection processing;

The deinterleaving unit 204 is configured to perform deinterleaving processing on the data information after performing basic signal detection processing on the signal detecting unit 203, and the pattern used in the deinterleaving is determined by the interleaving pattern information;

The decoding unit 205 is configured to perform channel decoding processing on the data information after the deinterleaving process, and the interleaving unit 206 is configured to perform interleaving processing on the data information decoded by the decoding unit 205. And the interleaved data is sent to the basic signal detecting unit 203, and the pattern used by the interleaving is determined by the received interleaving pattern information. The obtaining unit 207 is configured to obtain the decoding unit 205. Decoding the processed data information; the loop control unit 208 is configured to determine whether the data processing needs to be stopped, and if the determination is yes, notify the obtaining unit 207 to obtain the data information after the decoding processing; otherwise, notify The interleaving unit 206 performs interleaving processing on the data after channel decoding processing by the decoding unit 205. The loop control unit 208 includes at least one of a maximum number of loops control unit and a decode verifying unit, wherein the maximum loop count control unit is configured to determine whether the number of loops reaches a preset maximum number of loops, and if the determination is yes, notify the The obtaining unit 207 obtains the data information processed by the decoding unit 205; the decoding verifying unit is configured to determine whether the data information after the channel decoding is detected by the CRC check, and if the determination is yes, notify the The obtaining unit 207 obtains the data information processed by the decoding unit 205.

Correspondingly, FIG. 3 and FIG. 4 are schematic flowcharts of an embodiment of a data transmitting method and a data receiving method of the MU-MIMO system of the present invention, respectively.

As shown in FIG. 3, the data sending method in this embodiment specifically includes: Step S400: performing channel coding processing on data information sent to multiple receiving ends; Step S401: performing spreading processing on the encoded data information; The sender of the data is also The spread spectrum processing flow may not be included. Spread spectrum processing reduces the bit rate of the transmitted data.

Step S402, performing interleaving processing on the data information after the spreading processing; and data of different receiving ends are interleaved by using different interleaving patterns. In a specific implementation, the interleaving process may be a random interleaving process, and different interleaving patterns are generated by different random seeds; the interleaving process may also adopt a block interleaving processing manner, a convolutional interleaving processing manner, or a truncated bit inversion interleaving processing manner. . In general, the interleaving pattern is generated according to a predefined rule, but the interleaving pattern can also be generated by the transmitting end and notified to the receiving end in a specific manner. However, no matter which method is used to generate the interleaving pattern, the transmitting end needs to send the interleaving pattern information used for the data information of each receiving end to the plurality of receiving ends through control signaling. The interleaving process scrambles the order of the original code sequences, making the adjacent chips approximation-independent, making it easy for the receiver to detect chip-based multi-user data.

Step S403, performing modulation processing on the data information after the interleaving process;

Step S404, performing pre-processing on the data information after the modulation processing. In a specific implementation, the pre-processing includes one of a precoding process, a pre-equalization process, a pre-interference cancellation process, a beamforming process, and a space-time coding process. Or a plurality of, specifically, precoding processing, pre-processing, pre-equalizing the modulated data information by a pre-coding technique, pre-processing the modulated data information by using a pre-equalization technique, and the pre-interference cancellation processing is used in advance The interference and noise that may exist when the signal is transmitted in the physical channel are eliminated, and the beamforming process is used to perform beamforming processing on the data information modulated by the modulation unit. In an actual system, each receiving end feeds back the CSI of the channel and the quantized channel parameters to the transmitting end. The transmitting end can perform corresponding preprocessing according to the feedback information. For example, the precoding matrix is obtained by using the channel parameter calculation at the receiving end, and the index information of the codeword used by the precoding is notified by the feedback information, and after receiving the index information, the transmitting end can select the corresponding precoding. Matrix parameters, precoding the data to be sent.

Step S405, sending data information after the pre-processing unit to the plurality of receiving ends, and Interleaving pattern information used for data information of each receiving end, a spreading factor, a spreading code, and an offset parameter used for the data information of each receiving end, and the data information used for each of the receiving ends The pre-processing mode information is sent to the multiple receiving ends; the relevant parameters used in the specific implementation of the spread spectrum may be pre-agreed by the transmitting end and the receiving end, and need not be transmitted during the data transmission process.

As shown in FIG. 4, the data receiving method in this embodiment specifically includes:

Step S500, receiving data information sent to a plurality of receiving ends, and interleaving pattern information used by the data information, and spreading factors, spreading codes, and partial offsets used when performing spreading processing on data information sent to the plurality of receiving ends The shift parameter and the pre-processing mode information for pre-processing the data information sent to the plurality of receiving ends; the relevant parameters used in the specific implementation of the spread spectrum may be agreed in advance by the transmitting end and the receiving end, and do not need to be transmitted in the data. Received during the process.

Step S501: Perform channel equalization processing on the received data information. In a specific implementation, the channel J^J balance method includes a minimum minimum linear error (L-MMSE) and a forced minimum Zero-Forcing (ZF) equalization, Maximum Likelihood (ML) equalization, Serial Interference Cancellation (SIC) equalization, Parallel Interference Cancellation (PIC) equalization Kind. In the specific implementation, when performing signal equalization on the received signal, combining the pre-processing mode information sent by the transmitting end, the channel response parameter and other related parameters, calculating the channel response parameter, CSI and other related parameters of the system, and then transmitting and transmitting the data through the quantization. At the end, the sender can further perform corresponding preprocessing according to the information.

Step S502, performing basic signal detection processing on the data information after the channel equalization processing; Step S503, performing deinterleaving processing on the data information after the basic signal detection processing; and using the interlaced pattern by the deinterleaving pattern Information determination;

Step S504, performing channel decoding processing on the data information after the deinterleaving process;

Step S505, determining whether it is necessary to stop data processing, if the determination is yes, executing step S507; Then, in step S506, the step of determining whether to stop the data processing specifically includes determining whether the number of loops reaches a preset maximum number of loops. If the determination is yes, step S507 is performed; otherwise, step S506 is performed; or Whether the data information after the channel decoding is detected by the CRC check, if the determination is yes, step S507 is performed; otherwise, step S506 is performed;

Step S506, performing interleaving processing on the data information after the channel decoding process, and then performing step S502; the pattern adopted by the interleaving is determined by the interleaving pattern information;

Step S507, obtaining data information after the channel decoding process.

The data transmission of the MU-MIMO system and the corresponding data receiving scheme of the embodiment of the present invention are described in detail below.

First introduce the data transmission scheme:

After the transmitting end performs channel coding on the data information sent to the multiple receiving ends, each obtained coding block is interleaved by using different interleaving patterns, and the interleaved data is modulated and then transmitted by the antenna to the channel, and the specific implementation is as follows. Figure 5 shows. Assuming that there is group data sent to a user terminal, it may also be referred to as having a data stream. The processing procedure of the data stream of the kth user is taken as an example to illustrate the processing of the sender: setting the information code of the data stream of the kth user The meta-sequence is ^ = [4(1), ···, 4(0,···, 400] where / is the length of the sequence of information symbols; then it is encoded by the channel coding unit to become the code sequence ^, set the code The length of the sequence is /; and after the interleaving unit { }, the interleaving units of different data streams are different, and the coding sequence ^ is rearranged into a chip sequence in a disordered order = [3⁄4 (1), ···, 3⁄4 (), ··, 3⁄4 (J), the length of the chip sequence is the same as the length of the code sequence. J. The elements in the output sequence of the interleave unit are called chips, which are in accordance with the convention of the CDMA system. The chip sequence enters the modulation unit, and is modulated to be ^^ = [ (1), ···, (»ί),···, (Μ)] , Μ is the length of a set of data symbols. The group data symbols are transmitted through a multi-antenna system, and one signal is transmitted on each antenna.

Where different data streams of different users are interleaved using different interleaving patterns, that is, individual data The interleaving unit { } of the stream is different. The interleaving unit scrambles the order of the original coding sequences, making the adjacent chips approximately irrelevant, making signal detection between the chips and the chips easier. In order to achieve the best interleaving performance, the interleaving unit may employ a random interleaving unit, and different interleaving patterns are generated by different random seeds. In addition, in order to reduce the complexity of the interleaving unit, a block interleaving unit or a convolutional interleaving unit or a Pruned Bit-Reversal Interleave unit or the like may be employed. In general, the interleaving pattern is generated according to a predefined rule, and may also be notified by the transmitting end to notify the receiving end. Either way, the transmitting end must indicate the interleaving pattern used by the receiving end to interleave each data stream through control signaling.

Preferably, the coded sequence ( ^z ) encoded by the channel coding unit is set to be length-spread by the spreading unit to further reduce the code rate, and each coded symbol is coded to be low after being spread. The code rate code sequence ^{Ck U)} = [ ^{( )} ' ^(/) Γ , where / is the length of the low bit rate code sequence. The coding unit and the spread spectrum unit are combined to form a low code rate coding unit. When the spread spectrum unit is used, the transmitting end needs to indicate the relevant parameters used by the receiving end for spreading the data streams through the control signaling, such as the spreading factor, the starting parameter of the spreading code, and the spreading code offset parameter. Etc., the relevant parameters used in the specific implementation of the spread spectrum can be pre-agreed by the sender and the receiver, and do not need to be transmitted during the data transmission. The multi-antenna system transmits out, wherein the pre-processing unit may include the following processing situations: [1] 波束 beamforming processing, which may be: multiplying the data symbols by a weighting matrix, and then mapping to the physical layer to transmit The antenna is transmitted to reduce interference between multiple users. [2] Precoding processing can be: multiplying the data symbol by a precoding matrix to enable the receiver to receive the SNR/SINR of the signal. / channel capacity / signal power maximum; when the transmitting end performs precoding processing, the selection of the precoding matrix is generated by the receiving end through the corresponding matrix of the channel and certain rules. Usually, at The sender and receiver pre-store the codeword set to reduce the amount of feedback. [3] Pre-equalization technology, the specific method is: equalizing the signal or performing interference suppression before the signal is transmitted, so as to achieve the purpose of transmitting the data sent to a certain user to the designated user; [4] Pre-interference cancellation (Interference Pre -Subtraction) technology, the specific way is: By pre-sending the signal in the physical channel, the interference and noise that may come from the outside world are removed from the transmitting signal of the transmitting end, so as to achieve the purpose that multiple users can correctly receive their respective signals; [5] MIMO processing. Typically, space time coding techniques. Space-time coding techniques include spatial transmit diversity techniques and spatial multiplexing techniques. Among them, the spatial transmit diversity technology refers to transmitting data symbols of the same data stream on different antennas, thereby achieving the effect of transmit diversity, and having a strong anti-fading capability. Space Time Block Coding (STBC) is a typical application of space transmit diversity technology. Spatial multiplexing technology is different from spatial transmit diversity technology in that it transmits data symbols of different data streams on different antennas. Spatial multiplexing technology truly reflects the essence of MIMO system to improve capacity. Layered space-time code (BLAST) is space. Typical application of multiplexing technology. Typical space-time coding techniques are STBC, Space Time Trellis Coding (STTC), BLAST, and the like. Of course, the embodiment of the present invention not only adopts these three typical space-time coding technologies, but also includes a variant coding technique based on the three space-time coding technologies. In addition, space-time coding technology can also introduce different phase offsets in different transmit antennas, such as PSD (Phase shift diversity); or introduce time delays such as CDD (Cyclic delay diversity). technology. Space Frequency Block Coding (SFBC) is a typical application of space-frequency coding, which corresponds to a space-time block code, that is, the time domain of the space-time block code becomes the frequency domain of the space-frequency block code. Note that the above five processing modes can be used in combination of one or more. The preprocessed signal is modulated and transmitted to the frequency of the system. At the same time, the transmitting end notifies the receiving end of the interleaving pattern and the preprocessing processing mode through the control signaling. For example, when the transmitting end adopts precoding technology, the transmitting end should notify the receiving through control signaling. The pre-interference cancellation processing method is described in more detail. Assume that there is an antenna at the transmitting end, and the user receiving end antenna ^^二^,..., where, represents the number of receiving ends, that is, there is only one receiving antenna at each receiving end. Then the channel response matrix of the system is expressed as:

Where /3⁄4. represents the channel response parameter from the first transmit antenna to the first receive end. Based on the above-mentioned channel corresponding matrix Η, the pre-filtering factor W of the ZF (Zero Forcing) pre-filtering scheme in the pre-equalization scheme is expressed as:

Where (^^ represents the ith column of the conjugate transposed matrix of the matrix. I I represents the Frobenius paradigm. When each receiver has more than one receive antenna, the derivation process is similar.

Accordingly, the pre-interference cancellation scheme uses DPC (Dirty Paper Coding) encoding at the transmitting end. The idea of DPC coding is to first remove interference and noise from the signal before the signal is transmitted. In the MU-MIMO system, the transmitting end selects different preprocessing weighting factors (called codewords) for different receiving ends. The transmitting end first allocates a codeword (Codeword) to the receiving end 1, and then assigns a code to the receiving end 2, but the codeword allocated to the receiving end 2 satisfies the condition for removing the interference of the receiving end 1. Similarly, the codeword allocated to the receiving end 3 should satisfy the condition that the receiving end 1 and the receiving end 2 interfere with it. When there is only one receiving antenna at each receiving end, the DPC encoding becomes a beamforming based Scalar coding.

Assume that the channel response matrix W is decomposed by 2R, ie H = 2R. Where R is a lower triangular matrix, β is a χ Μ ^ matrix, satisfying ββ ^Η =

The precoding factor W is expressed as: The received signal is expressed as: = Ri + . (3) ^ indicates the received signal, indicating the transmitted signal, indicating the interference signal.

The received signal at the receiving end k is expressed as (4): ( ⁴ )

Therefore the channel is decomposed into a parallel interference channel. Since R is a lower triangular matrix, so the first

The channel of one receiving end is a SISO (Single-Input Single-Output) channel, the channel of the second receiving end is an interference channel including the signal of the first receiving end, and the channel of the third receiving end is the first receiving end. The channel that interferes with the second receiver, and so on. For the above reasons, the effects between the parallel channels are eliminated in advance at the transmitting end. The scheme transmits at the transmitting end with the following symbols:

3⁄4 , k = l, . ; K (5)

After preprocessing using equation (5), the received signal can be re-represented as (6):

k = l, - , K ( ₆₎ Next, introduce the data receiving scheme:

At the transmitting end, pre-filtering, precoding, MIMO beamforming techniques, and the like are performed by pre-processing the information transmitted to the designated receiving end. The pre-processed signal ideally eliminates interference between multiple receiver signals. Ideally, the interference between multiple receiver signals is completely eliminated, but is usually limited by the error in quantization during feedback. The influence of factors such as faster channel change, the preprocessing of the transmitting end can only partially eliminate the interference between the signals of multiple receiving ends at the receiving end. Therefore, when a receiving end receives the information transmitted to it by the transmitting end, it also receives the information transmitted by the transmitting end to the other receiving end. In order to further reduce the interference between multiple users, the receiving end performs multiple iterations on the received signals of multiple receiving ends to implement interference cancellation, and each signal passing through the signal detection is performed during each iteration. The signal at the receiving end is deinterleaved, decoded, and interleaved, and then the signal is detected again. The interference of the other receiving end signals is removed from each receiving end signal and then the next iteration is performed. After multiple iterations, it is usually possible to completely eliminate the interference of the signals of other receiving ends in each receiving end, thereby improving the signal.

SINR, improving reception performance, as shown in Figure 6. The receiving end includes at least one Elementary Signal Estimator (ESE). After receiving the signals of the plurality of receiving ends, the receiving antennas of the receiving unit send the signals of the plurality of receiving ends to the basic signal detecting unit as a priori information. It is assumed that the receiving antenna receives a signal sent to a user terminal, and the signal of the user is referred to as a shared channel signal. The first signal is taken as an example for description, and the basic signal detecting unit outputs the relevant extrinsic log likelihood. Log-Likelihood Ratio (LLR), which is commonly referred to as Extrinsic Information, is expressed as e _ESE c _k (J; e ( ( ) deinterleaved as the k-th channel decoding unit (Decoder, DEC) After inputting the a priori information, the channel decoding unit also generates a corresponding external information, denoted as e _DEC (x _k (j)); after being interleaved by the same interleaving pattern as the transmitting end, it is returned to the basic signal detecting unit, Updating the mean and variance of the noise as the a priori information input by the basic signal detecting unit in the second iteration. After many iterations, the channel decoding units of the plurality of data streams respectively generate hard decision values of the corresponding signal information, that is, Estimated value of multiple data streams. External information generated by the basic signal detecting unit and the channel decoding unit, completes a global chip-to-chip Turbo type Iterate over the receiving process.

Preferably, the data receiving apparatus of the MU-MIMO system of the embodiment further includes a channel equalization unit, and the multiple signals received by the receiving unit first pass through the channel equalization unit to eliminate or reduce interference between data symbols, and pass through the channel equalization unit. The subsequent multiplexed signal enters the basic signal detecting unit and performs multiple iterations. During the subsequent iterations, the channel equalization unit may or may not pass through the unit each time.

Commonly used channel equalization techniques include: Minimum Mean Square Error ( Linear Minimum Mean-Squared Error, L-MMSE), Zero-Forcing (ZF), Maximum Likelihood (ML), Successive Interference Cancellation (SIC), Parallel Interference Cancellation (PIC), etc. . In a specific implementation, when performing signal equalization on the received signal, combining with the pre-processing mode information sent by the transmitting end, calculating channel response parameters, CSI and other related parameters of the system, and feeding back the quantized information to the transmitting end, where the transmitting end is Further pre-processing can be performed based on this information.

The most typical signal equalization techniques are L-MMSE and ZF.

The following is a specific example to illustrate the principle of receiving signals at the receiving end. It is assumed that in a certain transmission period, the transmitting end of the MU-MIMO system is preprocessed and then transmitted to the user via multiple (at least one) transmitting antennas (Ρ=1,·· ·, Κ) transmit signal (assuming P = l, and there are 2 receiving antennas). In a specific implementation, each user may also be more than 2 receiving antennas. Referring specifically to FIG. 7, there are a total of 用户 users in the MU-MIMO system, and there are L modulation symbols in one interleave block at the transmitting end. The data stream sent by the transmitting end to the user is expressed as: S _k ={s^, S ₂ ^k , -, S _L ^k }, and the receiving signals of the two receiving antennas of the user P in the first receiving period are expressed as:

( ₇ ) where /^ = l, 2. = l, ..., L) represents the signal received by user P at the ''th antenna' during the first reception period. Represents the equivalent channel response coefficient after preprocessing from the first data stream to the first receive antenna when transmitting /(1 = 1-, L) symbols. In the ideal case, the equivalent channel response coefficient after preprocessing is used, and unequal ===0. In the actual case, (≠ is not always zero, so there is interference between multiple users. _3⁄4 ( = 1,2. = 1,..., ) indicates that user P is the first in the first receiving cycle. Interference and noise on the receiving antenna.

The two receiving antennas of user P receive signals in the mth (m = 1, · · ·, L) receiving periods, which are expressed as: I m +h ^m ₂ 2s m+---+hr L _k ks _m m ^k +---+ +

Signal multi-user interference signal

Useful signal multi-user interference signal

Available from (7)

(9) Available from (8)

The same reason

Where m = l,..., L represents the data length of an interleaved block sent to a user.

The following describes the basic principles of equalizing the signal sequence through the ZF equalizer and the L-MMSE equalizer.

(1) Equalize the signal sequence through the ZF equalizer

For the equations (9)-(11), the signal sequences are respectively equalized, and the corresponding equalization factors are ¹ , ..., ..., .

(13)

Where (*)" represents the conjugate transpose of the matrix *, [* represents the inverse matrix of the matrix *.

For the same reason, for the equations (9)-(11), the signal sequences, ···, ,..·, are respectively equalized, and the corresponding equalization factors are respectively, ···, ,···, ^

^ =[ ^)"•(^)1 -(H _LK f ₍₁₇₎ For the equations (9)-(11), the signal sequences are respectively equalized to obtain an estimated value for transmitting the data to the user 1.

In the same way, the signal sequences, ···, ,··., are separately equalized, and an estimated value of the data sent to the user is obtained.

(2) Equalize the signal sequence through the L-MMSE equalizer

For the equations (9)-(11), the signal sequences, ···, ,··· are separately equalized, and the corresponding equalization factors are ^,..., ,...,^

= [( · (H _n ) + "/ - ¹ ' (H _u ) ^Η ₍₂₀₎

(twenty one)

Where (*f represents the conjugate transpose of the matrix *, Γ ¹ represents the inverse matrix of the matrix *. where = σ ² /Ρ ₅ , represents the noise variance, P _s represents the transmitted signal power, and _σ ² represents the noise power of the received signal , / _2χ2 is the unit matrix of 2x2.

For the same reason, for the equations (9)-(11), the signal sequences, ···, ,··· are separately equalized, and the corresponding equalization factors are respectively, ···, ,...,!^

(twenty three)

(25) For the equations (9)-(ll), the signal sequences, ···, ,··· are separately equalized, and an estimated value for transmitting the data to the user 1 is obtained.

In the same way, the signal sequences, ···, ,··· are separately equalized, and an estimated value of the data sent to the user is obtained.

(27) As described above, when the ZF channel equalization receiver is used, the data estimated values transmitted to the user 1 and the user are obtained as in the equations (18) and (19); when the receiver is equalized using the L-MMSE channel, it is transmitted to the user. 1 and the user's data estimates are as shown in equations (26) and (27). By analogy, the data stream of each user is obtained by the channel equalization receiver, . . . , 3⁄4, . . . , the data is an estimate containing noise and interference. n .., _{K is} sent to the basic signal detector to calculate relevant external information and other parameters, and the relevant parameters and signals are sent to the decoder through the deinterleaver; the decoder generates a corresponding external information, which is returned by the interleaver The channel equalization receiver simultaneously updates the corresponding noise mean and variance as a priori information for the second iteration of the channel equalization detector input. Until the loop control unit determines that the number of loop iterations reaches a preset maximum number of loops, or the loop control unit determines whether the data information decoded by the decoder is detected by the CRC check. At this point, the data stream output by the decoder eliminates the effects of his sequence. To further illustrate the solution provided by the embodiment of the present invention, the data transmission in the MU-MIMO system and the corresponding receiving scheme are introduced based on the IEEE802.16e protocol.

For ease of presentation and ease of understanding, two basic concepts are defined first, namely "layer" and "flow". The so-called "layer" refers to the path of the information input to the pre-processing unit. If the M-channel data stream enters the pre-processing unit, then the sender has M-layer data; the so-called "stream" refers to the information path output from the pre-processing unit, such as After the M layer data has N output signals after the preprocessing unit, the transmitting end has N data streams.

8 is a schematic diagram of an embodiment of a data transmission scheme of an OFDMA MU-MIMO system based on the IEEE802.16e protocol; as shown in FIG. 8, in an OFDMA MU-MIMO system, a data stream is sent to a user at a transmitting end. There is a transmitting antenna at the transmitting end. The data streams are respectively channel-coded by a channel coder, and then spread by a spreader to reduce the code rate, and then the data streams pass through different interleavers. The interleaved data enters the modulation module, and the modulation module implements the function of constellation mapping. The modulated layer data is preprocessed. The processing may be performed by one or more preprocessing methods such as precoding processing, pre-equalization processing, pre-interference cancellation processing, beamforming processing, and space-time encoding processing. The preprocessed signal forms a channel data stream, and then performs operations such as subcarrier mapping and subcarrier randomization. The mapping of subcarriers implements the mapping process of logical subcarriers to physical subcarriers. The main purpose of randomization of carriers is to reduce the PAPR (Peak to Average Power Ratio) of subcarriers. In the subcarrier mapping process, if necessary, it also includes data segmentation or puncturing of data, insertion of pilot signals, and multiplication of each subcarrier by a specific factor. Thereafter, an IFFT (Inverse Fast Fourier Transform) transform is performed to generate an OFDMA (Orthogonal Frequency Division Multiplex Access) symbol. Then, a CP (Cyclic Prefix) is inserted in front of each OFDM symbol to eliminate ISI and Inter-Carrier Interference introduced by the multipath delay spread of the radio channel. Next, ODFMA [mu] _[tau] symbol streams are data streams through a filter, dried The filter accelerates the attenuation of the out-of-band leakage signal to prevent interference with other signals. The filtered signal is converted into a digital signal to an analog signal by a digital-to-analog conversion module. The analog signal enters the transmitting module and is transmitted to the outside through the antenna after high frequency modulation.

In the solution of the present invention, the mapping rules of the interleavers used for the data streams of different layers are different, and the generation of the rules must be random and opposite. The interleaver scrambles the order of the principle coding sequences, making adjacent chips approximation-independent, making it easy for the receiver to detect multi-user signals between chips and chips. At the same time, the transmitting end notifies the receiving end to use the relevant information of the interleaving pattern through control signaling.

FIG. 9 is a schematic diagram showing an embodiment of a data receiving scheme of an OFDMA MU-MIMO system of the IEEE802.16e protocol; as shown in FIG. 9, the first user of the H殳 has _3⁄4 receiving antennas. The M _3⁄4 receiving antennas receive signals, first extracting an analog signal of the signal from the high frequency carrier in the receiving module, and then converting the analog signal into a digital signal through an analog to digital conversion module. Then, the two signals are respectively removed by the filter to remove the interference sideband components. Next, the CP of each OFDMA symbol in the _3⁄4 way is removed, respectively, to eliminate ISI and ICI. Then, the M _Rk path signals are respectively subjected to FFT (Fast Fourier Transform) to realize the demodulation function of the OFDMA symbol. The signal demodulated by the OFDMA symbol passes through the mapping of the subcarriers and the inverse of the randomization of the subcarriers. The processed signal then enters the signal detection module. The signal detection module includes a channel equalization receiving module and an ESE basic signal detecting module. The interference between the main data symbols of the channel equalization module and the influence of the channel; the ESE basic signal detecting module generates corresponding external information according to the received signal, and the external information is deinterleaved to be a priori information of the input end of the channel decoder, and then The channel decoder generates a corresponding external information, which is interleaved and returned to the signal detection module (including ESE and channel equalization receiver) to update the mean and variance of the noise as a priori information of the second iterative basic signal detector input. . After many iterations, the decoders of the multi-layer data stream respectively generate hard decision values for the corresponding information sequences.

At the receiving end, the interleaver pattern used is the same as the interleaver at the transmitting end, that is, the transmitting end uses The interleaver { } is the same as the interleaver { } at the receiving end, and the synchronization process is implemented by downlink control signaling. At the same time, the interleaver used in the same way corresponds to its de-interleaver, that is, the { } interleaver corresponds to the deinterleaver.

The data transmission method and the corresponding data receiving method and apparatus in the multi-antenna system provided by the embodiment of the present invention, the data information of the plurality of receiving ends are respectively interleaved at the transmitting end, and different interleaving patterns are used, which disturbs the original coding sequence. The order makes the adjacent chips approximately irrelevant, so that the detection of the signals at the multiple receiving ends between the chips and the chips becomes easier; the received data is iteratively repeated at the receiving end, thereby effectively improving the received signals. The signal to interference and noise ratio reduces the bit error rate and bit error rate, effectively improving the performance of the multi-antenna system.

The above are only the preferred embodiments of the present invention, and the scope of the present invention is not limited thereto, and the equivalent variations made by the claims of the present invention are still within the scope of the present invention.

Claims

Rights request

A data transmission method for a multi-antenna system, comprising:

Performing channel coding, interleaving, and modulation processing on the data information sent to the multiple receiving ends, where the data information sent to each receiving end is separately interleaved by using different interleaving patterns;

The data transmission method of the multi-antenna system according to claim 1, further comprising: spreading the data information between channel coding and interleaving of the data information sent to the plurality of receiving ends deal with;

And transmitting, to the plurality of receiving ends, a spreading factor, a spreading code, and an offset parameter used by the data information.

The data transmission method of the multi-antenna system according to claim 1 or 2, further comprising:

Preprocessing the modulated data information;

And sending the pre-processed data information and the pre-processed pre-processing mode information to the plurality of receiving ends.

The data transmitting method of the multi-antenna system according to claim 3, wherein the pre-processing comprises pre-coding processing, pre-equalization processing, pre-interference cancellation processing, multi-input multi-output beamforming processing, and nulling One or more of the time encoding processes.

A data transmitting apparatus for a multi-antenna system, comprising:

a coding unit, configured to perform channel coding processing on data information sent to multiple receiving ends, and an interleaving unit, configured to perform interleaving processing on the encoded data information, where The data information sent to each receiving end is respectively subjected to interleaving processing by using different interleaving patterns; the modulating unit is configured to perform modulation processing on the data information after the interleaving processing;

The data transmitting apparatus of the multi-antenna system according to claim 5, further comprising: a spreading unit, configured to perform frequency-spreading processing on the data information subjected to channel coding processing by the coding unit, and then send the data information to The interleaving unit transmits a spreading factor, a spreading code, and an offset parameter used for the data information to the sending unit.

The data transmitting apparatus of the multi-antenna system according to claim 5 or 6, further comprising:

And a pre-processing unit, configured to perform pre-processing on the modulated data information of the modulation unit, and send the pre-processed data information and the pre-processed pre-processing mode information to the sending unit.

The data transmitting apparatus of the multi-antenna system according to claim 7, wherein the pre-processing unit comprises a pre-coding processing unit, a pre-equalization processing unit, a pre-interference cancellation processing unit, a beamforming processing unit, and a space time One or more of encoding processing units; wherein

The precoding processing unit is configured to perform precoding processing on the data information modulated by the modulation unit, and send the precoded data information and the processing information of the precoding processing to the Sending unit

The pre-equalization processing unit is configured to perform pre-equalization processing on the data information modulated by the modulation unit, and send the pre-equalization processed data information and the processing information of the pre-equalization processing to the Sending unit

The pre-interference cancellation processing unit is configured to perform data processing on the modulation unit after the modulation unit Performing pre-interference cancellation processing, and transmitting the pre-interference cancellation processed data information and the processing information of the pre-interference cancellation processing to the transmitting unit;

The beamforming processing unit is configured to perform beamforming processing on the data information after the modulation unit modulation processing, and send the beamforming processed data information and the beamforming processing processing mode information to the Sending unit

The space-time coding processing unit is configured to perform space-time coding processing on the data information modulated by the modulation unit, and perform the space-time coded data information and the processing information of the space-time coding process. Send to the sending unit.

9. A data receiving method for a multi-antenna system, comprising:

Receiving data information sent to the plurality of receiving ends and interleaving pattern information used by the data information;

Performing basic signal detection, deinterleaving, and channel decoding processing on the received data information to obtain data information after the channel decoding process, and the pattern used by the deinterleaving is determined by the received interleaving pattern information. .

The data receiving method of the multi-antenna system according to claim 9, wherein the performing basic signal detection, deinterleaving, and channel decoding processing on the received data information further includes: determining whether Stopping the data processing, if the determination is yes, obtaining the data information after the decoding processing; otherwise, after interleaving the data after the channel decoding processing, performing basic signal detection processing, the pattern adopted by the interleaving is The received interleaving pattern information is determined.

The data receiving method of the multi-antenna system according to claim 9, further comprising:

And a spreading factor, a spreading code, and an offset parameter used when performing spreading processing on the data information sent to the plurality of receiving ends.

The data receiving method of the multi-antenna system according to claim 10, wherein the determining whether the data processing needs to be stopped, and if the determination is yes, obtaining the data information after the decoding processing; otherwise, After the channel decoding processed data is interleaved, a basic signal detecting process is performed, and the pattern adopted by the interleaving is determined by the received interleaving pattern information, including:

Determining whether the number of loops reaches a preset maximum number of loops. If the determination is yes, obtaining the data information after the decoding process; otherwise, performing interleaving on the data after the channel decoding process, performing basic signal detection processing ;

Or determining whether the data information after the channel decoding is detected by a CRC check; if the determination is yes, obtaining the data information after the decoding process; otherwise, interleaving the data after the channel decoding process , Perform basic signal detection processing.

13. A data receiving apparatus for a multi-antenna system, comprising:

a receiving unit, configured to receive data information sent to multiple receiving ends and interleaved pattern information used by the data information;

14. The data receiving apparatus of the multiple antenna system according to claim 13, further comprising:

An interleaving unit, configured to perform interleaving processing on data information after performing channel decoding processing on the decoding unit, and send the interleaved data to the basic signal detecting unit, where the interleaving is performed a pattern is determined by the received interleaving pattern information;

a loop control unit, configured to determine whether the data processing needs to be stopped, and if the determination is yes, notifying the obtaining unit to obtain the data information after the decoding processing; otherwise, informing the interleaving unit to perform channel translation on the decoding unit The coded data is interleaved.