WO2007107110A1

WO2007107110A1 - A method and system of transmitting signal in multi-antenna system

Info

Publication number: WO2007107110A1
Application number: PCT/CN2007/000894
Authority: WO
Inventors: Hufei Zhu; Jianfei Tong; Yi Lu; Tao Wu; Yinggang Du
Original assignee: Huawei Technologies Co., Ltd.
Priority date: 2006-03-20
Filing date: 2007-03-20
Publication date: 2007-09-27
Also published as: CN101043241A

Abstract

The invention discloses a method and system to transmit the signal in multi-antenna communication. The method includes: set M transmitting antennas in the transmitter of MIMO system; the transmitter transmits k parallel signal with k transmitting antennas in every symbol period of TTI through space multiplexing, and a or plurality of the remaining M-K antennas is/are used to transmit signal, and K<M. The present invention makes remaining transmitting antennas to code by STC to obtain diversity gain according to the feedback transmitting antenna number less than the maximum of the available number of transmitting antennas in SCW mode. The invention also discloses an automatic retransmission method in multi-antenna system.

Description

Method and system for transmitting signals in multi-antenna communication This application claims to be Chinese patent filed on March 20, 2006, the Chinese Patent Office, Application No. 200610071303.8, entitled "A Method and System for Transmitting Signals in Multi-Antenna Communication" Priority of the application, the priority of the Chinese Patent Application, filed on Jan. 10, 2007, to the Chinese Patent Application No. 200710004560.4, entitled "Multi-antenna Communication Method and System", the entire contents of which are incorporated herein by reference. .

TECHNICAL FIELD The present invention relates to the field of communications, and more particularly to a method and system for transmitting signals in multi-antenna communication. Background technique

Multi-input and multi-output (MIMO) technology refers to the use of multiple transmit and receive antennas at the transmitting end and the receiving end, respectively. The signal is transmitted and received through multiple antennas at the transmitting end and the receiving end, thereby improving each Quality of service (bit error rate or data rate) of users. The traditional communication system is a Single-Input Single-Output (SISO) system. Multiple-Input Single-Output (MISO) and Single-Input Multiple-Output (SIMO) methods based on transmit diversity and receive diversity are also part of MIMO.

Currently in MIMO technology, the Alamouti space-time block code is used to transmit signals to obtain diversity gain. In the Alamouti space-time block code technique, two transmit antennas are used simultaneously, and signals are transmitted in the manner shown in FIG. One or more receive antennas can be used at the receiving end, and the diversity gain of the two transmit antennas can be obtained for the receiving end.

Space-Time Coding (STC) utilizes the spatial diversity gain provided by the MIMO channel. In the commonly used BER-SNR (Bit Error Rate - Signal to Noise Ratio) curve, it appears as Can get a steeper slope. STC can be divided into STTC (Space Time Trellis Coding), ST Turbo Code (Space Time Turbo Code), STBC (Space Time Block Coding) according to different coding methods. Block coding), differential STBC (DSTBC), etc., Alamouti scheme is one of STBC Simple and classic example.

The prior art provides a method for performing MIMO communication using a SCW (Single Code Word) mode, that is, a single code word mode. In the single codeword mode, on a plurality of virtual transmitting antennas, only one channel-encoded data stream is transmitted at each moment, and multiple symbols in the data stream are serial-to-parallel converted, and then distributed to each virtual transmitting antenna for transmission. . At each ΤΉ (transmit time interval), the receiver only feeds back one CQI (Channel Quality Indicator) information and one ACK/NACK (ACK is Acknowledge, indicating that the receiver acknowledges that it has received and correctly decoded. This path data, and NACK is Not Acknowledge, indicating that the receiving end does not acknowledge that the data has been received and correctly decoded, and the CQI information tells the transmitting end what kind of MCS the data is encoded in the corresponding TTI transmission. (The modulation and channel coding scheme), and the ACK/NACK information tells the transmitting end whether the data encoded by the corresponding one channel has been correctly decoded by the receiving end.

For the above transmission method, the receiver can be a simple linear receiver, such as a space-time or space-frequency implementation of a well-known MMSE (Minimum Mean Square )) equalizer, or a complex spatial multiplex transmission. A receiver that performs nonlinear joint demodulation of data, such as a nonlinear receiver using interference cancellation techniques.

In the existing SCW mode, the receiving end feeds back the spatially multiplexed (Rank) Κ, and the transmitting end uses all available M transmitting antennas in each symbol period in one 根据 according to the dimension K. K performs spatial multiplexing; the transmitting end uses all M transmitting antennas alternately in each symbol period within one TTI, that is, each transmitting antenna is used in turn, instead of only using K fixed in M. For example, there are M=4 transmit antennas 1, 2, 3, and 4 at the transmitting end. If K=2 transmit antennas are used in signal transmission, 2 transmit antennas are used for each symbol period, but which 2 are used. The transmitting antenna varies with different symbol periods. Several symbol periods are used for transmitting antennas 1, 2, several symbol periods are used for transmitting antennas 3, 4, and several symbol periods are used for transmitting antennas 2, 3... The transmit antennas used are alternately changed in sequence. There is another type in the prior art, in which the receiving end not only feeds back to the transmitting end to use K of all available M transmitting antennas, but also feedbacks to the transmitting end which K transmitting antennas are fixed in the M transmitting antennas.

The concept of ΤΉ and symbol periods described above is introduced here. In order to combat channel fading, as well as channel interference and noise transmission errors, the transmitting end divides the data to be transmitted into multiple data packets (blocks), channel coding and interleaving the information bits in the same data packet, and then modulating Multiple symbols are transmitted over the channel, and the length of time required to transmit such a packet determines the length of one TTI. The receiving end first receives all the symbols contained in the same data packet, and then deinterleaves and decodes. In the present invention, a TTI refers to the time interval at which such a packet is transmitted.

And each symbol in a data packet transmitted in a TTI may be distributed in different intervals in the time domain, or in different intervals in the frequency domain, or in different two-dimensional planes in the time domain and the frequency domain. Interval. A symbol period described herein refers to an interval occupied by a symbol transmitted through a channel in the time domain, or an interval occupied in the frequency domain, or an interval occupied on a two-dimensional plane in the time domain and the frequency domain. For example, in a MIMO OFDM communication scheme described in a standard document, one data packet uses 8 OFDM symbols in the time domain, and each OFDM symbol occupies 16 subcarriers in the frequency domain, then one symbol period refers to the time domain. And an interval on the two-dimensional plane of the frequency domain, that is, one subcarrier on one OFDM symbol in the time domain, and the data packet has 8x16-128 symbol periods.

In the above prior art solution, if the dimension of the spatial multiplexing fed back by the receiving end is K<M, only K of the M transmitting antennas are used for transmission at each time, so that the remaining MK cannot be fully utilized. The transmit antenna improves the performance of signal transmission. .,

For the SCW mode, a turbo coding channel coding scheme can be employed. The data stream to be transmitted is first subjected to operations such as channel coding, channel interleaving, rate matching, and constellation mapping, and then the data streams of the same rate of K channels are respectively transmitted through different antennas (K is less than or equal to M, and M is transmitted). The number of antennas). At the transmitting end, as shown in FIG. 2, the transmitting modulation device uses the data stream to be transmitted. A unified channel coder, RM (rate matching) and modulation mode, and then divide all the data into K-channel data streams of the same rate, and then transmit them through different antennas.

As shown in FIG. 2, the channel coding module 202 is a Turbo code of 1/5 code rate. The channel interleaving module 204 performs bit separation and bit permutation. The rate matching module 206 punctates or repeats the sequence sent by the channel interleaving module 204 according to the required length. The splitter 208 distributes the rate-matched sequences to the respective antennas according to a certain rule. In the existing SCW, the information bits in the sequence are evenly distributed to the respective antennas. The modulation module 210 includes two sub-modules, a constellation mapping module 211 and a channelization processing module 212, wherein the constellation mapping module can adopt BPSK (Binary Phase Shift Keying) or QPSK (Quarature Phase). -Shift Keying, Quadrature Phase Shift Keying), or 8PSK, or 16QAM (16 Quantized Amplitude Modulation), or 64QAM modulation, channelization including OFDM (Orthogonal Furequency Division Multiplexity) In addition to frequency division multiplexing, or spread spectrum, etc., the transmission modulation apparatus further includes a plurality of transmitting modules, which may be antennas.

SCW has less feedback in this way, and since there is only one channel encoder used, the CRC (Cyclic Redundancy Code) check is for all transmit antennas, so HARQ (Hybrid Automatic Repeat Request) The hybrid automatic retransmission mechanism is relatively simple. Once the CRC check shows an error, all data currently processed is retransmitted, and only one ACK/NACK signal is needed.

Summary of the invention

Embodiments of the present invention provide a method and system for transmitting signals in multi-antenna communication to fully utilize respective transmit antennas.

A method for transmitting a signal in multi-antenna communication is provided in an embodiment of the present invention, including: setting M transmit antennas at a transmitting end of a MIMO system;

The transmitting end uses the K transmitting antennas to transmit the K-channel transmitting signals in parallel in the spatial multiplexing manner in each symbol period of the UI, and simultaneously uses at least one of the remaining MK transmitting antennas to transmit the day. Line emission signal, where K < M.

The embodiment of the present invention further provides a method for transmitting a signal in multi-antenna communication, comprising: setting M transmit antennas at a transmitting end of a MIMO system, for transmitting a K-channel transmit signal, wherein K<M;

At least one of the K-channel transmit signals, encoded, transmitted by at least two transmit antennas, and in one frame, the coded at least one transmit signal transmitted by at least two transmit antennas, at least two transmit antennas used The combination changes at least once.

The embodiment of the present invention further provides a system for transmitting signals in multi-antenna communication, including a transmitting end of M transmitting antennas, wherein K transmitting antennas transmit signals, and the K < M, further comprising: receiving feedback information a unit, configured to obtain, by the receiving end, feedback to the transmitting end, the transmitting antenna usage information, and according to the feedback information, confirm that the transmitting signal uses the number of transmitting antennas K;

And a transmitting signal setting unit, configured to set one or more of the remaining M-K transmitting antennas to perform a space-time code transmitting signal according to the K, to obtain a diversity gain.

In an embodiment of the solution, when the number of transmit antennas used according to feedback in the single codeword mode is less than the maximum number of available transmit antennas, the remaining transmit antennas are used as space time block coding to obtain diversity. Gain. DRAWINGS

1 is a schematic diagram of transmitting Alamouti space-time block code using two transmit antennas in the prior art; FIG. 2 is a block diagram of a prior art transmit modulation apparatus;

3 is a flowchart of a method for transmitting a signal in multi-antenna communication according to an embodiment of the present invention; and FIG. 4 is a schematic structural diagram of a system for transmitting a multi-antenna communication according to an embodiment of the present invention. detailed description

Specific embodiments of the present invention are described below in conjunction with the drawings.

As shown in FIG. 3, it is a flow chart of a transmitting signal in the embodiment of the present invention. The solution has M transmitting antennas at the transmitting end, and the transmitting end uses K transmitting antennas to transmit in parallel in each symbol period of the TTI. The spatially multiplexed K-channel transmits signals and simultaneously transmits signals using one or more of the remaining MK transmit antennas, where K < M.

As can be seen from Figure 3, the main steps are as follows:

301. Set M transmit antennas at the transmitting end of the MIMO system.

Optionally, assuming that the MIMO system is a closed-loop system, the receiving end feeds back the transmitting antenna usage information to the transmitting end, indicating that the next TTI can simultaneously transmit the number of different transmitted signals of the respective channels in parallel by spatial multiplexing, the Κ In the embodiment of the present invention, actually, the number of different transmission signals of the next transmission that can be simultaneously transmitted in parallel by spatial multiplexing, the Κ < Μ; if Κ = Μ, then the current There are technologies.

The receiving end feedbacks the spatially multiplexed dimension (Rank) 根据 according to the received information, and instructs the transmitting end to perform spatial multiplexing using one of all available virtual transmitting antennas in the next frame according to the dimension Κ. .

302. The transmitting end transmits a signal by using one of the transmitting antennas in the ,, and simultaneously transmits the signal by using one or more of the remaining Μ-Κ transmitting antennas, where the Μ-Κ transmitting for transmitting the signal Each of one or more of the antennas transmits a set of space time block codes along with one of the one of the transmit antennas used to transmit the signal.

After receiving the antenna usage information fed back by the receiving end, the transmitting end confirms the number of transmitting antennas that must be used in the next 根据 according to the indication, and transmits a signal using the determined one of the transmitting antennas in the ΤΉ. In an embodiment of the inventive scheme, one or more of the remaining Μ-Κ transmit antennas are simultaneously used to transmit a signal to the space-time block code to obtain a diversity gain.

In the prior art, only two transmitting antennas or four transmitting antennas are generally considered at the transmitting end. The following is an example of the case where the transmitting end has two transmitting antennas or four transmitting antennas, and the diversity gain is obtained by using the embodiment of the present invention. Signal transmission process.

The transmit antenna used in the SCW mode in the embodiment of the present invention may be a virtual transmit antenna or a physical transmit antenna. When discussing signal transmission performance, the two may be equivalently processed. in case Is a virtual transmit antenna, which can multiply a vector composed of the transmitted signals by one or more matrices to obtain a result vector, and then transmit each of the result vectors by different transmitting antennas at the transmitting end and reach the receiving end through one channel. Just fine.

In the process discussed below, the concept of a physical transmit antenna is used, and the conclusion can naturally be extended to the case of using a virtual transmit antenna.

Option 1: There are M = 2 transmitting antennas at the transmitting end.

Two transmit antennas are set at the transmitting end. If the spatially multiplexed dimension 反馈=1 fed back by the receiving end, only one transmitting antenna is used for each 现 in the prior art, and the signal transmitting form is as shown in FIG. The transmitted signal is transmitted using transmit antenna 1 in a number of consecutive symbols in a frame, and transmitted using transmit antenna 2 in successive consecutive symbols.

In the method of the embodiment of the present invention, if the dimension of the spatial multiplexing fed back by the receiving end is K=l, and all the two transmitting antennas are used for each time or subcarrier, the Alamouti space-time division coding scheme may be adopted, and the signal is transmitted. The form is:

The 1 and 2 columns of the transmit matrix correspond to transmit antenna 1 and transmit antenna 2, and the 2 rows of the transmit matrix correspond to two consecutive points in the time domain, or in the frequency domain, or in the time and frequency domains. It is easy to see from the signal transmission scheme of the first scheme that the spatial diversity gain can be obtained at the receiving end.

The distance between each row of the above-mentioned transmit matrix is not necessarily one symbol, but may be multiple symbols, and may refer to multiple sub-carrier intervals in the frequency domain.

Option 2: There are M = 4 transmitting antennas at the transmitting end.

There are a variety of situations in scenario 2, depending on the dimension K of the spatial multiplexing fed back by the receiver, which is described below.

1. If the dimension of the spatial multiplexing fed back by the receiving end is K=l, only one transmitting antenna is used for each moment or subcarrier in the prior art, and the signal is in the form of: ~s _t 0 0 0 one

0 s _i+l 0 0

0 0 s _i+2 0

0 0 s. ₊₃ means that the normally transmitted signal is transmitted using the transmitting antenna 1 in several consecutive symbols in the TTI, and is transmitted using the transmitting antenna 2 in the next consecutive symbols, followed by the transmitting antenna 3 and The transmitting antenna 4 transmits, so that the transmitting antennas 1, 2, 3, 4 alternately circulate.

The form of signal transmission in the embodiment of the present invention is:

0 0

*

One 0 0

0 0

* *

0 0

*

- 0 0

0 ^S i+6 ^S i+7 0

* *

0 a ^S iYJ ^S i+6 0

0 0

*

0 ~ ^S i+9 0

0 0

* *

A ¹ ll 0 ^+io 0 The two matrices of the above matrix are a set of Alamouti space-time block code periods, and a total of 6 Alamouti space-time block code periods, which can arbitrarily change the order of each Alamouti space-time block code period, in a slowly changing channel. It is also possible to arbitrarily change the rows of the matrix. That is, within a plurality of consecutive symbols, two of the four transmit antennas are used for combination, and a set of Alamouti space-time block codes are transmitted. By this transmission mode, one of the transmit antennas is designated, and one of the remaining three transmit antennas transmits the space-time block code together with the designated transmit antenna, and it is apparent that the diversity gain can be obtained.

2. If the dimension of the spatial multiplexing fed back by the receiving end is K=2, the prior art uses only two transmitting antennas for signal transmission at each moment or subcarrier. The form of signal transmission is:

That is, usually the transmitted signal is transmitted using the transmitting antenna 1 and the transmitting antenna 2 in consecutive symbols, and is transmitted using the transmitting antenna 2 and the transmitting antenna 3 in successive consecutive symbols, and subsequently using the transmitting antenna 3 and the transmitting antenna 4 in sequence. The combination and the combination of the transmitting antenna 1 and the transmitting antenna 3 perform signal transmission, so that the two-two combinations of the transmitting antennas 1, 2, 3, 4 are alternately cycled.

The form of signal transmission in the embodiment of the present invention is:

It can be seen from the above-mentioned emission matrix that the first and second rows are the antennas 1 and 2, the antennas 3, 4 are grouped, the Alamouti space-time block codes in the group, and the inter-group spatial multiplexing; the third and fourth rows The antennas 1 and 3 are grouped together, the antennas 2, 4 are grouped, the Alamouti space-time block code is grouped, and the space is multiplexed between groups; the 5th and 6th rows are the antennas 1 and 4, and the antennas 2 and 3 are composed. A group, Alamouti space-time block code within a group, spatial multiplexing between groups. By this transmission method, all the remaining antennas after the designated transmitting antenna are used to transmit the space-time block code together with the designated antenna, and it is apparent that the diversity gain can be obtained.

3. If the dimension of the spatial multiplexing fed back by the receiving end is K=3, only 3 transmitting antennas are used at each moment or subcarrier in the prior art, and the signal transmission form is: ^S i+2 0

0 ^S i+4

^S i ₊ 6 0 ^S i+7

^S i+9 ^+io 0 ^s i+n

That is, usually the transmitted signal is transmitted using the transmitting antenna 1, the transmitting antenna 2 and the transmitting antenna 3 in consecutive symbols, and is transmitted using the transmitting antenna 2, the transmitting antenna 3 and the transmitting antenna 4 in successive consecutive symbols, followed by It is transmitted by a combination of the transmitting antenna 1, the transmitting antenna 3 and the transmitting antenna 4, and the combination of the transmitting antenna 1, the transmitting antenna 2, and the transmitting antenna 4, so that the three-three combinations of the transmitting antennas 1, 2, 3, 4 are alternately cycled.

The form of signal transmission in the embodiment of the present invention is:

Here, A is a signal transmitted by two transmitting antennas using an Alamouti space-time block code, and 'is a signal transmitted by spatial multiplexing using one transmitting antenna.

It can be seen from the above-mentioned emission matrix that the first and second rows are a group of the transmitting antenna 1 and the transmitting antenna 2, the intra-group Alamouti space-time block code, and the inter-group spatial multiplexing, and the transmitting antenna 3 and the transmitting antenna 4 are respectively transmitted. signal. Lines 3 and 4 are a group of transmitting antenna 1 and transmitting antenna 3, within the group Alamouti Space-time block code, and inter-group spatial multiplexing, while transmit antenna 2 and transmit antenna 4 respectively transmit signals; lines 5 and 6 are a group of transmit antenna 1 and transmit antenna 4, group Alamouti space-time block code, group The space is multiplexed, and the transmitting antenna 2 and the transmitting antenna 3 respectively transmit signals, and so on. By this transmission method, it is apparent that the diversity gain can be obtained.

The above scheme can be used for other morphing processes to generate new schemes. For example, instead of using the Alamouti space-time block code, other transmission schemes that can achieve diversity gain, especially other space-time block codes, are exemplified below.

If there is a case where the transmitting end has M = 4 transmitting antennas, if the dimension of the spatial multiplexing of the feedback of the receiving end is K=l, any one of the following two types of transmission may be used in the embodiment of the present invention:

The four columns of the above matrix respectively correspond to four transmitting antennas; the four rows of the above matrix respectively correspond to adjacent four symbol periods, so-called adjacent, which may be adjacent in the time domain or adjacent in the frequency domain. x _{i 5} i=l, 2, 3, 4 denote different symbols, and X* denotes a conjugate of a complex number X.

Or,

The four columns of the above matrix respectively correspond to four transmitting antennas; the four rows of the above matrix respectively correspond to adjacent four symbol periods, so-called adjacent, which may be adjacent in the time domain or adjacent in the frequency domain. Xi, i=l, 2, 3 denotes different symbols, and x* denotes a conjugate of a complex number x.

The embodiment of the present invention is to use the remaining antennas for the space-time diversity gain, such as the Alamouti space-time block code to obtain the spatial diversity gain, and the remaining antennas also transmit signals to obtain the diversity gain, which can be used with any space. The coding method of diversity gain.

In an embodiment of the inventive solution, when the number of virtual antennas used for feedback is less than the maximum number of available virtual antennas, the remaining antennas are used as short time block codes to obtain diversity gain. The transmit antenna resources are fully utilized and the system performance is greatly enhanced by the diversity gain achieved.

As shown in FIG. 4, it is a schematic structural diagram of a system for transmitting signals in multi-antenna communication according to an embodiment of the present invention. As can be seen from the figure, the system includes a transmitting end 41 and a receiving end 42, and the transmitting end 41 includes M transmitting antennas, and transmits The terminal 41 uses K transmit antennas to transmit signals, and the K < M, the system further includes:

The feedback information receiving unit 401 is configured to: the receiving end 42 feeds back the transmitting antenna usage information to the transmitting end, and according to the feedback information, confirms the number K of different transmitting signals of different TTIs that can be simultaneously transmitted in parallel through spatial multiplexing;

The transmit signal setting unit 402 is configured to set one or more of the remaining M-K transmit antennas to perform a null-time block code transmission signal according to the K, to obtain a diversity gain.

The above transmitting antenna is a physical transmitting antenna or a virtual transmitting antenna.

In the above embodiment, the signals are transmitted using space time block code coding to obtain the spatial diversity gain. The present invention is not limited to this coding mode, and other coding methods can be used to obtain spatial diversity gain. For example, for channel coding OFDM communication systems, delay coding mode, CSD (Cyclic Shift Diversity), can also be used. In addition, it is also possible to use both the delay diversity coding method and the space-time block code coding method to achieve better spatial diversity.

When the solution of the embodiment of the present invention is applied to an OFDM communication system with channel coding, the receiving end feeds back the transmitting antenna usage information to the transmitting end, and indicates the number K of different transmitting signals of different TTIs that can be simultaneously transmitted in parallel by spatial multiplexing. In the case of K < M, the transmitting end is in the TTI Transmitting, by means of K transmit antennas, spatially multiplexing, simultaneously transmitting the chopped transmit signals in parallel, and simultaneously using one or more of the remaining one or more transmit antennas, using space time block code coding, or The coding mode of the delay diversity, or the coding mode of the time-delay diversity and the coding mode of the space-time block code, are transmitted to obtain a spatial diversity gain. The specific implementation is as follows: In the case that there are 发射=4 transmit antennas at the transmitting end, if the dimension of the spatial multiplexing fed back by the receiving end is Κ=3, the embodiment of the present invention may also adopt the following transmission form to transmit Κ=3. The road signal, that is, the encoded result of using the delay diversity of one of the signals transmitted by the transmitting antenna 1 and the transmitting antenna 2, and the transmitting antenna 3 and the transmitting antenna 4 respectively transmit a spatially multiplexed one signal.

In the case that there are 发射=4 transmit antennas at the transmitting end, if the dimension of the spatial multiplexing fed back by the receiving end is Κ=3, the embodiment of the present invention can also transmit the K=l signal by using the following transmission form, that is, first The signal is encoded by the Alamouti space-time block code method, and the signal encoded by the 2-way Alamouti space-time block code is obtained, and the signal encoded by the first Alamouti space-time block code is encoded by the time-diversity diversity method CSD. The signal is sent to the transmitting antenna 1 and the transmitting antenna 2, and the signal encoded by the second Alamouti space-time block code is encoded by the time-diversity diversity method CSD and sent to the transmitting antenna 3 and the transmitting antenna 4.

In the embodiment of the present invention, when the dimension of the spatial multiplexing fed back by the receiving end is K=3, and the transmitting end has four transmitting antennas, namely, the transmitting antenna 1, the transmitting antenna 2, the transmitting antenna 3, and the transmitting antenna 4, The form of signal transmission is:

As described above, here, _Si is a signal transmitted by two transmitting antennas using an Alamouti space-time block code, and t is a signal transmitted by spatial multiplexing using one transmitting antenna. Each column of the above matrix corresponds to one transmitting antenna, and each row represents one symbol period, and the symbol periods corresponding to the first, second, third, and fourth rows are adjacent in the time domain or the frequency domain, or at least two adjacent The channel conditions of the two symbol periods corresponding to the row can be approximately considered to remain unchanged. The above scheme, indicating that the transmit antenna combination used to transmit the Alamouti space-time block code has a change in the symbol period of different Alamouti space-time block codes until a possible combination of 2 antennas and 2 antennas is traversed in one frame, and each is made The number of times the combination is used is as equal as possible.

The above solution is used for the case where the feedback constitutes a closed loop, that is, the case where the receiving end feeds back the channel quality indication to the transmitting end. However, it will be apparent to those skilled in the art that the above solution can be used for both closed loop and open loop, because the implementation of the above solution does not depend on the closed loop or open loop, that is, whether the receiving end is transmitting or not. The end feedback channel quality indication is not a prerequisite for implementing the above solution. In other words, the foregoing implementation of the solution in the embodiment of the present invention is as follows: the transmitting end of the MIMO system has M transmitting antennas transmitting K-way (K is smaller than M) data streams, thereby idling in the prior art (MI The transmit antenna is also used to transmit signals to obtain spatial diversity gain; implementation conditions are not The limiting receiving end must feed back the transmitting antenna usage information to the transmitting end to indicate the number K of different transmitting signals of a different TTI that can be simultaneously transmitted in parallel by spatial multiplexing.

In addition, it is not limited to a signal transmitted by two transmitting antennas using an Alamouti space-time block code, or a signal transmitted by two transmitting antennas after encoding by a time diversity diversity CSD method. If there are M=5 transmit antennas at the transmitting end, and the corresponding one signal is encoded and then transmitted by using three transmit antennas, then A can also use the delay diversity method and the space-time block code coding to transmit with three transmit antennas. The signal, the specific coding method is as described above.

It can be seen that, by using the technical solution provided by the embodiment of the present invention, in the case of open loop, the fluctuation of the value of the effective signal to noise ratio caused by the arrangement change of each column of the channel matrix can be eliminated, thereby reducing the effective signal noise of each data packet. Better than the fluctuations, to achieve better error rate performance. In the case of closed loop, because the channel quality indication fed back from the receiving end to the transmitting end, there is a certain erasure probability, that is, the receiving end considers that the channel quality indication of the feedback is unreliable without using the current feedback value, but based on past feedback. The value derives the current channel quality, thereby reducing the fluctuation of the effective signal-to-noise ratio of each data packet, and also reducing the packet error rate.

It is apparent that those skilled in the art can make various modifications and variations to the invention without departing from the spirit and scope of the invention. Thus, it is intended that the present invention cover the modifications and variations of the inventions

Claims

Rights request

A method for transmitting a signal in multi-antenna communication, comprising:

M transmit antennas are arranged at the transmitting end of the MIMO system;

The transmitting end uses the K transmitting antennas in the TTI to transmit the K-channel transmitting signals in parallel by spatial multiplexing, and simultaneously transmits the antenna transmitting signals using at least one of the remaining M-K transmitting antennas, where K < M.

2. The method according to claim 1, wherein the spatially multiplexed K-channel transmission signal is a single-codeword mode signal, the method further comprising the step of: receiving, transmitting, by the receiving end to the transmitting end The antenna usage information indicates the number κ of different transmission signals of a certain TTI that can be simultaneously transmitted in parallel by spatial multiplexing.

3. The method according to claim 1, wherein at least one of the at least one transmitting antenna for transmitting a signal and the one of the plurality of transmitting antennas for transmitting a signal of the Μ-Κ transmitting antennas The signals are transmitted together using space time code coding and/or coding using delay diversity.

The method according to claim 1 or 2 or 3, wherein: Μ=2, K=l, at least one transmitting antenna for transmitting a signal among the MK transmitting antennas, and the using At least one of the K transmit antennas transmitting the signal is transmitted in the following mode:

Where Si is the symbol vector emitted at the transmitting antenna, S is the conjugate of the symbol vector Si, and i is a positive integer.

The method according to claim 1 or 2 or 3, wherein the M=4, K=l, at least one transmitting antenna for transmitting a signal in the Μ-Κ transmitting antennas, At least one of the two transmit antennas used to transmit the signal transmits the signal in the following mode: 0 0

* *

0 0

* *

0 0

* *

0 0

* *

0 ^S i ₊ 6 0

0 0

* *

0 ~ ^S i+9 0

0 0

* *

0 ^■+10 0 where Si is the symbol vector transmitted at the transmit antenna, S is the conjugate of the symbol vector Si, and i is a positive integer.

The method according to claim 1 or 2 or 3, wherein the M=4, K=l, at least one transmitting antenna for transmitting a signal in the MK transmitting antennas, and the using At least one of the K transmit antennas transmitting the signal, 发射 transmit the signal in the following mode: χι ^Χ 2 ^Χ 3

* * *

―

* * *

— ^Χ 4

^Χ 4 χ ₂ where Xi is the symbol vector transmitted by the transmitting antenna, X* represents the conjugate of the symbol vector X, and i is a positive integer.

The method according to claim 1 or 2 or 3, wherein the M=4, K=l, at least one transmitting antenna for transmitting a signal in the MK transmitting antennas, and the using At least one of the K transmit antennas transmitting the signal is transmitted in the following mode:

Where Xi is the symbol vector transmitted by the transmitting antenna, X* represents the conjugate of the symbol vector X, and i is positive

The method according to claim 1 or 2 or 3, wherein: M=4, K=2, at least one transmitting antenna for transmitting a signal in the Μ-Κ transmitting antennas, and At least one of the two transmit antennas used to transmit the signal transmits the signal in the following mode:

^S i+l ^•+2

* * * *

~ ^S i+l ~ ^S i+3

^S i+4 ^S i+5 ^S i+6

* * * *

~ ^S i+6

^+ΙΟ ^+l l

Where Si is the symbol vector transmitted at the transmitting antenna, S "is the conjugate of the symbol vector Si, and i is a positive integer.

The method according to claim 1 or 2 or 3, wherein the M=4, K=3, at least one transmitting antenna for transmitting a signal in the Μ-Κ transmitting antennas, At least one of the two transmit antennas used to transmit the signal transmits the signal in the following mode:

Where Si is the symbol vector transmitted at the transmitting antenna, S" is the conjugate of the symbol vector Si, ti is the symbol vector transmitted at the transmitting antenna, and i is a positive integer.

10. The method of claim 1 wherein the transmit antenna is a physical transmit antenna or a virtual transmit antenna.

11. The method of claim 1 wherein said transmitting signal uses an Alamouti space time block code encoding.

12. A method of transmitting a signal in multi-antenna communication, comprising:

M transmitting antennas are arranged at the transmitting end of the MIMO system for transmitting K-channel transmitting signals, wherein K<M;

At least one of the K-channel transmit signals is encoded and transmitted by at least two transmit antennas, and in one TTI, the coded at least one transmit signal transmitted by at least two transmit antennas, and at least two transmit antenna combinations used Change at least once.

13. The method according to claim 12, wherein the encoding is performed using a space time code encoding method and a /.

14. The method according to claim 12, wherein: said M=4, said K=3, ―the road signal is encoded and transmitted by two transmitting antennas, and is used in one ,, the road signal is used. The two transmit antennas change at least once in combination.

The method according to claim 12 or 14, wherein the encoding uses one signal transmitted by two transmitting antennas, and the combination of the two transmitting antennas used traverses all possible combinations in one turn. And make the number of times each combination is used as equal as possible.

16. A system for transmitting signals in multi-antenna communication, comprising: one transmitting antenna, transmitting a chopping signal simultaneously in parallel by using one of the transmitting antennas in one 通过 by spatial multiplexing, wherein Κ < Μ, characterized in that Also includes:

a feedback information receiving unit, configured to acquire transmit antenna usage information fed back by the receiving end to the transmitting end, and confirm, according to the feedback information, a number of transmit signals that can be simultaneously transmitted in parallel by spatial multiplexing in a cell;

And a transmitting signal setting unit, configured to set one or more of the remaining Μ-Κ transmitting antennas to perform a null time code transmission signal according to the Κ.

17. The system of claim 16, wherein the transmit antenna is a physical transmit antenna or a virtual transmit antenna.