CN101626263B - Data retransmission method, data sending device and communication system - Google Patents

Abstract

The embodiment of the invention discloses a data retransmission method, a data sending device and a communication system. The realization of the embodiment is used as an example: allocating data needing to be retransmitted to antennas of an antenna set comprising at least two antennas, reversing the data allocated by part of the antennas of the antenna set, carrying out precoding treatment on the data needing to be retransmitted, and sending the allocated data through the antenna set. Through the embodiment of the invention, when transmission channels of two data transmissions are the same, the combined signal-noise ratio is the average value of quadratic sums after each channel is subjected to mould delivery and is full diversity gain, thereby improving the utilization rate of wireless frequency spectrum resource.

Description

Data retransmission method, data sending device and communication system

Technical Field

The present invention relates to the field of communications technologies, and in particular, to a data retransmission method, a data transmission apparatus, and a communication system.

Background

With the development of wireless mobile communication services, users have made higher and higher demands on the rate and quality of service of wireless communication. But has limited further development of wireless communications due to increasing scarcity of wireless spectrum resources. The recent Multiple Input Multiple Output (MIMO) technology has attracted more and more attention to the improvement of the spectrum utilization and reliability of wireless communication systems, and has become a hot spot for research and discussion of various wireless communication standards.

MIMO technology improves spectrum utilization and improves reliability by multiple antennas of a transmitter and a receiver. MIMO techniques include two types, Spatial Diversity (SD) and Spatial Multiplexing (SM). Typical spatial Diversity techniques include Cyclic Delay Diversity (CDD), Space Time Block Coding (STBC), and Space Frequency Block Coding (SFBC).

The prior art CDD process is shown in fig. 1. The transmission signal is S (k) (power is 1, E (| S (k)), (Y)²) 1), modulating by Orthogonal Frequency Division Multiplexing (OFDM), copying to two paths, wherein the first path is not delayed, the second path cyclically delays d sampling points, adding Cyclic Prefix (CP) and then transmitting on the antenna. The received frequency domain signals are:

$Y\left(k\right)=S\left(k\right)/\sqrt{2}*H_1\left(k\right)+S\left(k\right)/\sqrt{2}*H_2\left(k\right)*e^{-\mathrm{<figure-callout\; id="2"\; label="j"\; filenames="S2008100406503E00032.png,S2008100406503E00041.png"\; state="\{\{state\}\}">j</figure-callout>}\frac{2\mathrm{\&pi;kd}}{N}}+n\left(k\right)$

$=S\left(k\right)/\sqrt{2}*(H_1\left(k\right)+H_2\left(k\right)*e^{-\mathrm{<figure-callout\; id="2"\; label="j"\; filenames="S2008100406503E00032.png,S2008100406503E00041.png"\; state="\{\{state\}\}">j</figure-callout>}\frac{2\mathrm{\&pi;kd}}{N}})+n\left(k\right)$ (formula 1)

Wherein H₁(k) For the channel from the first transmitting antenna to the receiving end, H₂(k) The channel from the second transmit antenna to the receiving end. Is divided by

Energy normalization is carried out on the transmitted signals, so that the total energy transmitted by the two antennas is 1. n (k) is white Gaussian noise and has a power of σ². N is the number of fast Fourier transform points.

If the data sent for the first time arrives at the receiver in error, the transmitter is required to perform retransmission, that is, the transmitter retransmits the data sent for the first time. The channel transmitted the second time is assumed to be the same as the channel transmitted the first time. The receiver combines the data received twice, and the signal-to-noise ratio after combination is as follows:

$\mathrm{SNR}=\frac{{|H_1\left(k\right)+H_2\left(k\right)*e^{-\mathrm{<figure-callout\; id="2"\; label="j"\; filenames="S2008100406503E00032.png,S2008100406503E00041.png"\; state="\{\{state\}\}">j</figure-callout>}\frac{2\mathrm{\&pi;kd}}{N}}|}^2}{{\mathrm{\&sigma;}}^2}$ (formula 2)

The prior art also provides that the retransmitted data is transmitted after being processed by space-time block coding, as shown in fig. 2. When the transmitter has 4 transmitting antennas, the four transmitting antennas are divided into two groups, and each group has two transmitting antennas. STBC transmit matrix $\left[\begin{array}{cc}{s}_1& -{\mathrm{<figure-callout\; id="2"\; label="s"\; filenames="S2008100406503E00032.png,S2008100406503E00041.png"\; state="\{\{state\}\}">s</figure-callout>}}_2^{*}\\ s_2& {\mathrm{<figure-callout\; id="1"\; label="s"\; filenames="S2008100406503E00012.png"\; state="\{\{state\}\}">s</figure-callout>}}_1^{*}\end{array}\right],$ Each row represents data to be transmitted for each group of transmit antennas, each column represents two adjacent OFDM symbol time instants (STBC), or each column representsTwo adjacent OFDM Subcarriers (SFBC) are shown.

STBC processing is such that, at a first OFDM symbol time, a first group of antennas transmits s₁Second group of antennas transmitting s₂(ii) a At a second OFDM symbol time, the first group of antennas transmits-s₂ ^*Second group of antennas transmitting s₁ ^*. The data to be transmitted by each group of antennas is mapped to the same subcarrier, and is copied into two paths after OFDM modulation, wherein one path is not delayed, and the other path is cyclically delayed by d_i(i ═ 1, 2). Each signal is transmitted after CP is added.

If the first transmission fails, performing hybrid automatic Repeat-reQuest (HARQ) retransmission, and performing Chase Combining (CC) on the data received twice by the receiver to obtain the snr of the combined data as:

$\mathrm{SNR}=\frac{{|H_1\left(k\right)+H_2\left(k\right)*e^{-\mathrm{<figure-callout\; id="2"\; label="j"\; filenames="S2008100406503E00032.png,S2008100406503E00041.png"\; state="\{\{state\}\}">j</figure-callout>}\frac{2\mathrm{\&pi;}{\mathrm{kd}}_1}{N}}|}^2{+|H_3\left(k\right)+H_4\left(k\right)*e^{-\mathrm{<figure-callout\; id="2"\; label="j"\; filenames="S2008100406503E00032.png,S2008100406503E00041.png"\; state="\{\{state\}\}">j</figure-callout>}\frac{2\mathrm{\&pi;}{\mathrm{kd}}_2}{N}}|}^2}{2*{\mathrm{\&sigma;}}^2}$ (formula 3)

Wherein H_i(k) Representing the channel from the ith antenna to the receiver.

The prior art also provides that the retransmission data is transmitted after spatial multiplexing processing, as shown in fig. 3, the transmission method of each group is the same as the transmission method after space-time block code processing, and the signal-to-noise ratio after combining is the same as formula 3.

The inventor finds the following problems in the prior art in the process of implementing the invention: although the prior art can obtain a certain diversity gain when retransmitting data sent last time, it can be seen from equations 2 and 3 that the signal-to-noise ratio after combining is not the average of the square sum after modulus taking of each channel, and is not the complete diversity gain, so the prior art still has a low utilization rate of wireless spectrum resources.

Disclosure of Invention

The technical problem to be solved in the embodiments of the present invention is to provide a data retransmission method and a data transmission apparatus, so as to improve the utilization rate of wireless spectrum resources.

In order to solve the above technical problem, the embodiment of the data retransmission method provided by the present invention can be implemented by the following technical solutions:

carrying out precoding processing on data needing to be retransmitted;

allocating data to be retransmitted to antennas of an antenna group, wherein the antenna group comprises at least two antennas;

negating data allocated to a part of antennas in the antenna group;

and transmitting the allocated data through the antenna group.

The technical scheme has the following beneficial effects: when the retransmission is the same as the channel of the previous transmission, the signal-to-noise ratio after combination is the average value of the square sum after modulus taking of each channel, and the complete diversity gain is achieved, so that the utilization rate of wireless frequency spectrum resources is improved.

Drawings

FIG. 1 is a schematic diagram of prior art emission after CDD processing;

FIG. 2 is a diagram of prior art transmission after space-time block coding;

FIG. 3 is a schematic diagram of prior art transmission after SM and CDD processing;

FIG. 4 is a flowchart of an embodiment of the method of the present invention;

FIG. 5 is a schematic diagram of the emission after CDD processing according to the second embodiment of the present invention;

FIG. 6 is a schematic diagram of transmission after space-time block code processing according to the third embodiment of the present invention;

FIG. 7 is a schematic diagram of an emission process after SM and CDD processing according to an embodiment of the present invention;

FIG. 8 is a schematic diagram of transmission after STBC, Precoding and CDD processing according to the embodiment of the present invention;

FIG. 9 is a schematic structural diagram of a sixth apparatus according to an embodiment of the present invention;

FIG. 10 is a schematic structural diagram of a seventh apparatus according to an embodiment of the present invention;

FIG. 11 is a schematic structural diagram of an eighth apparatus according to an embodiment of the present invention;

fig. 12 is a schematic structural diagram of a nine-system according to an embodiment of the present invention.

Detailed Description

The technical problem to be solved in the embodiments of the present invention is to provide a data retransmission method, a data transmission apparatus, and a corresponding communication system, so as to improve the utilization rate of wireless spectrum resources.

Referring to fig. 4, a first embodiment of the method of the present invention includes the steps of:

step 101: carrying out precoding processing on data needing to be retransmitted; the pre-coding processing of step 101 can be completed before step 104, without affecting the implementation of the embodiment of the present invention; the precoding processing manner will be described in more detail in the following embodiments;

step 102: allocating data to be retransmitted to antennas of an antenna group, the antenna group comprising at least two antennas; in the following embodiments, the antenna group including two or four antennas will be described in detail, and the principles of the antennas including other numbers are the same and will not be described again.

Step 103: negating data distributed by a part of antennas in the plurality of antennas;

step 104: and transmitting the allocated data through the antenna group.

When the antenna group includes two antennas, then the implementation may be:

step 101: carrying out precoding processing on data needing to be retransmitted;

step 102: distributing data to be retransmitted to two antennas of an antenna group;

step 103: negating data allocated to one of the two antennas; the data distributed by the other antenna is unchanged;

negating data allocated to one of the two antennas; the data allocated by the other antenna is unchanged, including the following cases:

and if the data sent by the two previous antennas are both positive, the data distributed by one antenna in the two antennas is taken as negative, and the data distributed by the other antenna is unchanged.

And if the data sent by the two previous antennas are negative, the data distributed by one antenna in the two antennas is positive, and the data distributed by the other antenna is unchanged.

If the data sent by the first antenna is positive and the data sent by the second antenna is negative, the data distributed by the first antenna is negative, and the data distributed by the second antenna is unchanged; or the data distributed by the second antenna is taken positive, and the data distributed by the first antenna is unchanged.

The negation is to negate the data that needs to be retransmitted as a whole, and may be (a-b) negation to- (a-b) or-a + b, for example.

Step 104: and transmitting the distributed data through an antenna group consisting of the two antennas.

The above method embodiments are not limited to using one set of antennas, and when multiple sets of antennas are used, the processing method of each set of antennas is the same as that of one set of antennas, and will not be described again.

In this embodiment, spatial multiplexing may be performed on the data that needs to be retransmitted.

In this embodiment, cyclic delay diversity processing and/or space-time block code processing may be performed on the data that needs to be retransmitted.

In this embodiment, cyclic delay diversity processing and/or space-frequency block code processing may be performed on the data that needs to be retransmitted.

The spatial multiplexing, cyclic delay diversity, space-time block code, and space-frequency block code processing may be performed before step 104.

According to the method, the data distributed by one antenna of the two antennas is inverted, and the data distributed by the other antenna is unchanged, so that complete diversity gain is achieved when transmission channels of two times of data transmission are the same, and the utilization rate of wireless spectrum resources is improved. Before the retransmission data is sent, the data to be retransmitted is subjected to spatial multiplexing processing, cyclic delay diversity processing, space-time block code processing and space-frequency block code processing, so that the advantages of the prior art can be further combined, and the utilization rate of wireless spectrum resources is improved.

In the following method, the following embodiment describes in detail the case where the data sent by the two antennas is positive, and the data allocated to one of the two antennas is negative, and the data allocated to the other antenna is not changed. The implementation methods of other cases are the same and are not described again.

The retransmission in the first embodiment may be a default retransmission, where the default retransmission refers to retransmission performed no matter whether an error occurs in the first transmission, and does not need to wait until the receiving end returns a retransmission request before performing retransmission; or the retransmission after the receiving end returns the retransmission request when the first transmission is wrong; it may also be a number of retransmissions, which still occur in error or which by default require a number of retransmissions. The embodiment of the present invention is described by taking an example that the first transmission is in error and needs to be retransmitted. In the process of implementing the invention, the principle of the default retransmission and the repeated retransmission is the same as that of the retransmission required when the first transmission is wrong. For ease of understanding and description, a previous transmission of a retransmission is defined as a first transmission and a retransmission is defined as a second transmission.

Several scenarios of combining the above-described method embodiments with MIMO technology will be described in detail below. Before data is sent, OFDM modulation 202 is required, CP processing 203 is added, at least one antenna in each group of antennas needs to perform delay processing 204 on the sent data, and antenna 205 is not described any more.

An example of the application of the embodiment of the method in a space diversity processing scenario is as follows: the second embodiment will be described in detail by taking a CDD scenario as an example, and the third embodiment will be described in detail by taking CDD and STBC or SFBC as examples. In the following embodiments, the data will be described by taking a frequency domain signal as an example, and it is understood that the format of the data may be other formats, and the method of the present invention is not limited.

In the second embodiment, the data to be retransmitted is transmitted after being CDD processed, please refer to fig. 5:

in the CDD system with two transmitting antennas, during the second transmission, the data which is distributed by one antenna of the two antennas and needs to be retransmitted is taken as negative. The CDD system carries out CDD processing on the data needing to be retransmitted, and can finish the CDD processing at any time before the retransmitted data are sent. The CDD system is not limited to the use of two antennas, and when more antennas are used, the antennas may be divided into two groups, and the processing of each group is the same as the processing of one group.

For the first transmission after CDD processing, multiplier 201 takes the positive sign; then, in the second transmission, the multiplier 201 takes a negative sign, so as to realize that the data to be retransmitted allocated to one of the two antennas is taken as a negative sign. The multiplier 201 is used in the present embodiment, but not limited to, as a method of negating data. The multiplier 201 appears in the following embodiments and is not described in detail.

Assuming that the two transmission channels are the same, the received signal-to-noise ratio for the first transmission is:

${\mathrm{<figure-callout\; id="1"\; label="SNR"\; filenames="S2008100406503E00012.png"\; state="\{\{state\}\}">SNR</figure-callout>}}_1=\frac{{|H_1\left(k\right)+H_2\left(k\right)*e^{-\mathrm{<figure-callout\; id="2"\; label="j"\; filenames="S2008100406503E00032.png,S2008100406503E00041.png"\; state="\{\{state\}\}">j</figure-callout>}\frac{2\mathrm{\&pi;kd}}{N}}|}^2}{2*{\mathrm{\&sigma;}}^2}$ (formula 4)

For the second transmission, the received frequency domain signal is:

$Y\left(k\right)=S\left(k\right)/\sqrt{2}*H_1\left(k\right)-S\left(k\right)/\sqrt{2}*H_2\left(k\right)*e^{-\mathrm{<figure-callout\; id="2"\; label="j"\; filenames="S2008100406503E00032.png,S2008100406503E00041.png"\; state="\{\{state\}\}">j</figure-callout>}\frac{2\mathrm{\&pi;kd}}{N}}+n\left(k\right)$

$=S\left(k\right)/\sqrt{2}*(H_1\left(k\right)-H_2\left(k\right)*e^{-\mathrm{<figure-callout\; id="2"\; label="j"\; filenames="S2008100406503E00032.png,S2008100406503E00041.png"\; state="\{\{state\}\}">j</figure-callout>}\frac{2\mathrm{\&pi;kd}}{N}})+n\left(k\right)$ (formula 5)

For the second transmission, the received signal-to-noise ratio is:

${\mathrm{<figure-callout\; id="2"\; label="SNR"\; filenames="S2008100406503E00032.png,S2008100406503E00041.png"\; state="\{\{state\}\}">SNR</figure-callout>}}_2=\frac{{|H_1\left(k\right)-H_2\left(k\right)*e^{-\mathrm{<figure-callout\; id="2"\; label="j"\; filenames="S2008100406503E00032.png,S2008100406503E00041.png"\; state="\{\{state\}\}">j</figure-callout>}\frac{2\mathrm{\&pi;kd}}{N}}|}^2}{2*{\mathrm{\&sigma;}}^2}$ (formula 6)

The receiver combines the two received data, and the signal-to-noise ratio after combination is the sum of formula 4 and formula 6, that is:

$\mathrm{SNR}={\mathrm{<figure-callout\; id="1"\; label="SNR"\; filenames="S2008100406503E00012.png"\; state="\{\{state\}\}">SNR</figure-callout>}}_1+{\mathrm{<figure-callout\; id="2"\; label="SNR"\; filenames="S2008100406503E00032.png,S2008100406503E00041.png"\; state="\{\{state\}\}">SNR</figure-callout>}}_2=\frac{{|H_1\left(k\right)+H_2\left(k\right)*e^{-\mathrm{<figure-callout\; id="2"\; label="j"\; filenames="S2008100406503E00032.png,S2008100406503E00041.png"\; state="\{\{state\}\}">j</figure-callout>}\frac{2\mathrm{\&pi;kd}}{N}}|}^2}{2*{\mathrm{\&sigma;}}^2}+\frac{{|H_1\left(k\right)-H_2\left(k\right)*e^{-\mathrm{<figure-callout\; id="2"\; label="j"\; filenames="S2008100406503E00032.png,S2008100406503E00041.png"\; state="\{\{state\}\}">j</figure-callout>}\frac{2\mathrm{\&pi;kd}}{N}}|}^2}{2*{\mathrm{\&sigma;}}^2}$

$=\frac{{\left|H_1\left(k\right)\right|}^2+{|H_2\left(k\right)*e^{-\mathrm{<figure-callout\; id="2"\; label="j"\; filenames="S2008100406503E00032.png,S2008100406503E00041.png"\; state="\{\{state\}\}">j</figure-callout>}\frac{2\mathrm{\&pi;kd}}{N}}|}^2}{{\mathrm{\&sigma;}}^2}=\frac{{\left|H_1\left(k\right)\right|}^2+{\left|H_2\left(k\right)\right|}^2}{{\mathrm{\&sigma;}}^2}$ (formula 7)

Formula 7 is after the second embodiment is combinedThe combined signal-to-noise ratio is the average value of the square sum of the moduli of each channel, and is a complete diversity gain, and has more diversity gains compared with the formula 2; if H is present₁(k) And H₂(k) The correlation is small, and equation 7 can still obtain more diversity gain than equation 2, thereby improving the utilization rate of wireless spectrum resources.

In the third embodiment, data to be retransmitted is transmitted after being processed by space-time block code and CDD, please refer to fig. 6:

the transmitter has 4 transmitting antennas, the 4 antennas are divided into two groups, each group has two antennas, the data to be retransmitted allocated to one of the two antennas is taken as negative, and the data to be retransmitted allocated to the other antenna is unchanged. In this embodiment, 4 antennas are used, but not limited to 4 antennas, and the embodiments of the present invention are not limited to two groups of transmit antennas, and when there are multiple groups of transmit antennas, the processing method of each group is the same as that of one group, and will not be described again.

Using STBC processing as an example, at a first OFDM symbol time, a first set of antennas transmits s₁Second group of antennas transmitting s₂(ii) a At a second OFDM symbol time, the first group of antennas transmits-s₂ ^*Second group of antennas transmitting s₁ ^*. The data to be transmitted by each group of antennas is mapped to the same subcarrier, and is copied into two paths after OFDM modulation, wherein one path is not delayed, and the other path is cyclically delayed by d_i(i ═ 1, 2). Each signal is transmitted after CP is added. When the first transmission fails, a second transmission is required. The second transmission is different from the first transmission by: and during the second transmission, negating the data needing to be retransmitted and distributed by one antenna in each group of antennas, and then sending the data needing to be retransmitted through the antenna group. The receiving method of the receiver is the same as the prior art. If the transmission channels of the two previous times and the two next times are the same, the following results are obtained:

for the first transmission, the received signal-to-noise ratio is:

${\mathrm{<figure-callout\; id="1"\; label="SNR"\; filenames="S2008100406503E00012.png"\; state="\{\{state\}\}">SNR</figure-callout>}}_1=\frac{{|H_1\left(k\right)+H_2\left(k\right)*e^{-\mathrm{<figure-callout\; id="2"\; label="j"\; filenames="S2008100406503E00032.png,S2008100406503E00041.png"\; state="\{\{state\}\}">j</figure-callout>}\frac{2\mathrm{\&pi;}{\mathrm{kd}}_1}{N}}|}^2+{|H_3\left(k\right)+H_4\left(k\right)*e^{-\mathrm{<figure-callout\; id="2"\; label="j"\; filenames="S2008100406503E00032.png,S2008100406503E00041.png"\; state="\{\{state\}\}">j</figure-callout>}\frac{2\mathrm{\&pi;}{\mathrm{kd}}_2}{N}}|}^2}{4*{\mathrm{\&sigma;}}^2}$ (formula 8)

For the second transmission, the received signal-to-noise ratio is:

${\mathrm{<figure-callout\; id="2"\; label="SNR"\; filenames="S2008100406503E00032.png,S2008100406503E00041.png"\; state="\{\{state\}\}">SNR</figure-callout>}}_2=\frac{{|H_1\left(k\right)-H_2\left(k\right)*e^{-\mathrm{<figure-callout\; id="2"\; label="j"\; filenames="S2008100406503E00032.png,S2008100406503E00041.png"\; state="\{\{state\}\}">j</figure-callout>}\frac{2\mathrm{\&pi;}{\mathrm{kd}}_1}{N}}|}^2+{|H_3\left(k\right)-H_4\left(k\right)*e^{-\mathrm{<figure-callout\; id="2"\; label="j"\; filenames="S2008100406503E00032.png,S2008100406503E00041.png"\; state="\{\{state\}\}">j</figure-callout>}\frac{2\mathrm{\&pi;}{\mathrm{kd}}_2}{N}}|}^2}{4*{\mathrm{\&sigma;}}^2}$ (formula 9)

The combined signal-to-noise ratio is:

${\mathrm{SNR}={\mathrm{<figure-callout\; id="1"\; label="SNR"\; filenames="S2008100406503E00012.png"\; state="\{\{state\}\}">SNR</figure-callout>}}_1+\mathrm{<figure-callout\; id="2"\; label="SNR"\; filenames="S2008100406503E00032.png,S2008100406503E00041.png"\; state="\{\{state\}\}">SNR</figure-callout>}}_2=\frac{{|H_1\left(k\right)+H_2\left(k\right)*e^{-\mathrm{<figure-callout\; id="2"\; label="j"\; filenames="S2008100406503E00032.png,S2008100406503E00041.png"\; state="\{\{state\}\}">j</figure-callout>}\frac{2\mathrm{\&pi;}{\mathrm{kd}}_1}{N}}|}^2+{|H_3\left(k\right)+H_4\left(k\right)*e^{-\mathrm{<figure-callout\; id="2"\; label="j"\; filenames="S2008100406503E00032.png,S2008100406503E00041.png"\; state="\{\{state\}\}">j</figure-callout>}\frac{2\mathrm{\&pi;}{\mathrm{kd}}_2}{N}}|}^2}{4*{\mathrm{\&sigma;}}^2}$

$+\frac{{|H_1\left(k\right)-H_2\left(k\right)*e^{-\mathrm{<figure-callout\; id="2"\; label="j"\; filenames="S2008100406503E00032.png,S2008100406503E00041.png"\; state="\{\{state\}\}">j</figure-callout>}\frac{2\mathrm{\&pi;}{\mathrm{kd}}_1}{N}}|}^2+{|H_3\left(k\right)-H_4\left(k\right)*e^{-\mathrm{<figure-callout\; id="2"\; label="j"\; filenames="S2008100406503E00032.png,S2008100406503E00041.png"\; state="\{\{state\}\}">j</figure-callout>}\frac{2\mathrm{\&pi;}{\mathrm{kd}}_2}{N}}|}^2}{4*{\mathrm{\&sigma;}}^2}$ (formula 10)

$=\frac{{{\left|H_1\left(k\right)\right|}^2+|H_2\left(k\right)*e^{-\mathrm{<figure-callout\; id="2"\; label="j"\; filenames="S2008100406503E00032.png,S2008100406503E00041.png"\; state="\{\{state\}\}">j</figure-callout>}\frac{2\mathrm{\&pi;}{\mathrm{kd}}_1}{N}}|}^2+{\left|H_3\left(k\right)\right|}^2+{|H_4\left(k\right)*e^{-\mathrm{<figure-callout\; id="2"\; label="j"\; filenames="S2008100406503E00032.png,S2008100406503E00041.png"\; state="\{\{state\}\}">j</figure-callout>}\frac{2\mathrm{\&pi;}{\mathrm{kd}}_2}{N}}|}^2}{2*{\mathrm{\&sigma;}}^2}$

$=\frac{{\left|H_1\left(k\right)\right|}^2+{\left|H_2\left(k\right)\right|}^2+{\left|H_3\left(k\right)\right|}^2+{\left|H_4\left(k\right)\right|}^2}{2*{\mathrm{\&sigma;}}^2}$

Equation 10 is the signal-to-noise ratio after the triple combination in the embodiment, and the signal-to-noise ratio after the triple combination is the average value of the square sum after the modulus of each channel, which is the complete diversity gain, and has more diversity gain compared with equation 3; if the correlation between the channels of the antennas in the group is small, equation 10 can obtain more diversity gain than equation 3, thereby improving the utilization rate of the wireless spectrum resources. The system combining STBC and CDD can complete CDD and STBC processing on data needing to be retransmitted at any time before the retransmitted data are sent. The SFBC processing and the STBC processing are the same in the method for realizing the embodiment of the invention and are not described again.

In the fourth embodiment, data to be retransmitted is transmitted after being processed by SM and CDD, please refer to fig. 7:

the transmitter has 4 transmitting antennas, the 4 antennas are divided into two groups, each group has two antennas, the data to be retransmitted allocated to one of the two antennas is taken as negative, and the data to be retransmitted allocated to the other antenna is unchanged. In this embodiment, 4 antennas are used, but not limited to 4 antennas, and the embodiments of the present invention are not limited to two groups of transmit antennas, and when there are multiple groups of transmit antennas, the processing method of each group is the same as that of one group, and will not be described again.

Take the example that after SM processing, CDD processing is performed on the data to be retransmitted. When the first transmission fails, a second transmission is required. The second transmission is different from the first transmission by: and during the second transmission, negating the data which is distributed by one antenna in each group of antennas and needs to be retransmitted, keeping the data which is distributed by the other antenna and needs to be retransmitted unchanged, and then sending the distributed data through the antenna group.

s₁And s₂May belong to the same encoded stream or may belong to different encoded streams. If s₁And s₂Belonging to the same coded stream, and negating data needing to be retransmitted and distributed in the two groups of antennas during retransmission; if s₁And s₂If the two antennas do not belong to the same coded stream, only one coded stream may have errors and need to be retransmitted, and at this time, only the data which are allocated in the two groups of antennas and need to be retransmitted are negatively charged. The SM and CDD combined system can complete SM and CDD processing on data needing to be retransmitted at any time before the retransmitted data is sent. The fourth embodiment may also perform only the SM process without being combined with the CDD process.

In the fourth embodiment, the implementation principle of each group is the same as that of the second embodiment, so that the retransmitted data can obtain a complete hierarchical gain in the group, thereby improving the utilization rate of the wireless spectrum resources.

In the first to fourth embodiments, if the two previous and subsequent transmission channels are the same, the combined signal-to-noise ratio is the average of the square sums of the modulo signals of the channels, which is the complete diversity gain; when the correlation of the front and back transmission channels is small, the embodiment can still obtain large diversity gain; thereby improving the utilization rate of wireless spectrum resources.

In a fifth embodiment, when the antenna group in step 101 includes four antennas, the implementation manner may be:

step 101: carrying out precoding processing on data needing to be retransmitted;

step 102: distributing data to be retransmitted to four antennas of an antenna group;

step 103: negating data distributed by two antennas in the four antennas; of course, the data allocated to one or three antennas of the antenna group may be inverted

Step 104: and sending the distributed data through the four antennas.

Taking the data to be retransmitted to be transmitted after space-frequency block code processing, Precoding processing (Precoding) and cyclic delay diversity processing as an example; please refer to fig. 8 for a transmission diagram;

for the STBC processed data signal; performing precoding processing, where the precoding matrix may be W, where W is a 4 × 2 precoding matrix, and of course W may be a matrix of another size; the CDD process is performed, D can be a 4 x 4 diagonal matrix, although D can be other diagonal matrices, where k is the carrier number and θ is the carrier number_iIs the frequency domain phase rotation for each antenna.

$S=\left[\begin{array}{cc}{s}_1& {-\mathrm{<figure-callout\; id="2"\; label="s"\; filenames="S2008100406503E00032.png,S2008100406503E00041.png"\; state="\{\{state\}\}">s</figure-callout>}}_2^{*}\\ s_2& {\mathrm{<figure-callout\; id="1"\; label="s"\; filenames="S2008100406503E00012.png"\; state="\{\{state\}\}">s</figure-callout>}}_1^{*}\end{array}\right]$ $W=\left[\begin{array}{cc}{w}_{11}& w_{21}\\ w_{12}& w_{22}\\ w_{13}& w_{23}\\ w_{14}& w_{24}\end{array}\right]$ $D=\left[\begin{array}{cccc}{e}^{j{\mathrm{\&theta;}}_{0}k}& & & 0\\ & e^{j{\mathrm{\&theta;}}_{1}k}& & \\ & & e^{j{\mathrm{\&theta;}}_{2}k}& \\ 0& & & e^{j{\mathrm{\&theta;}}_{3}k}\end{array}\right]$

When the data is sent for the first time, the STBC sends data to a receiving end at the first time, and the signal-to-noise ratio is as follows:

${\mathrm{<figure-callout\; id="1"\; label="r"\; filenames="S2008100406503E00012.png"\; state="\{\{state\}\}">r</figure-callout>}}_1=H\&times;D\&times;W\&times;S$

$=\left[\begin{array}{cccc}{h}_{11}& h_{21}& h_{31}& h_{41}\\ h_{12}& h_{22}& h_{32}& h_{42}\end{array}\right]\left[\begin{array}{cccc}{e}^{j{\mathrm{\&theta;}}_{0}k}& & & 0\\ & e^{j{\mathrm{\&theta;}}_{1}k}& & \\ & & e^{j{\mathrm{\&theta;}}_{2}k}& \\ 0& & & e^{j{\mathrm{\&theta;}}_{3}k}\end{array}\right]\&times;\left[\begin{array}{cc}{w}_{11}& w_{21}\\ w_{12}& w_{22}\\ w_{13}& w_{23}\\ w_{14}& w_{24}\end{array}\right]\&times;\left[\begin{array}{c}{s}_1\\ {\mathrm{<figure-callout\; id="2"\; label="s"\; filenames="S2008100406503E00032.png,S2008100406503E00041.png"\; state="\{\{state\}\}">s</figure-callout>}}_2\end{array}\right]$

$=\left[\begin{array}{cccc}{h}_{11}{e}^{j{\mathrm{\&theta;}}_{0}k}& h_{21}{e}^{j{\mathrm{\&theta;}}_{1}k}& h_{31}{e}^{j{\mathrm{\&theta;}}_{2}k}& h_{41}{e}^{j{\mathrm{\&theta;}}_{3}k}\\ h_{12}{e}^{j{\mathrm{\&theta;}}_{0}k}& h_{22}{e}^{j{\mathrm{\&theta;}}_{1}k}& h_{32}{e}^{j{\mathrm{\&theta;}}_{2}k}& h_{42}{e}^{j{\mathrm{\&theta;}}_{3}k}\end{array}\right]\&times;\left[\begin{array}{cc}{w}_{11}& w_{21}\\ w_{12}& w_{22}\\ w_{13}& w_{23}\\ w_{14}& w_{24}\end{array}\right]\&times;\left[\begin{array}{c}{s}_1\\ {\mathrm{<figure-callout\; id="2"\; label="s"\; filenames="S2008100406503E00032.png,S2008100406503E00041.png"\; state="\{\{state\}\}">s</figure-callout>}}_2\end{array}\right]$

$=\left[\begin{array}{cc}{p}_{11}& p_{12}\\ p_{21}& p_{22}\end{array}\right]\&times;\left[\begin{array}{c}{s}_1\\ {\mathrm{<figure-callout\; id="2"\; label="s"\; filenames="S2008100406503E00032.png,S2008100406503E00041.png"\; state="\{\{state\}\}">s</figure-callout>}}_2\end{array}\right]$

wherein, $\begin{array}{c}{p}_{11}=h_{11}{e}^{j{\mathrm{\&theta;}}_{0}k}{w}_{11}+h_{21}{e}^{j{\mathrm{\&theta;}}_{1}k}{w}_{12}+h_{31}{e}^{j{\mathrm{\&theta;}}_{2}k}{w}_{13}+h_{41}{e}^{j{\mathrm{\&theta;}}_{3}k}{w}_{14}\\ p_{12}=h_{11}{e}^{j{\mathrm{\&theta;}}_{0}k}{w}_{21}+h_{21}{e}^{j{\mathrm{\&theta;}}_{1}k}{w}_{22}+h_{31}{e}^{j{\mathrm{\&theta;}}_{2}k}{w}_{23}+h_{41}{e}^{j{\mathrm{\&theta;}}_{3}k}{w}_{24}\\ p_{21}=h_{12}{e}^{j{\mathrm{\&theta;}}_{0}k}{w}_{11}+h_{22}{e}^{j{\mathrm{\&theta;}}_{1}k}{w}_{12}+h_{32}{e}^{j{\mathrm{\&theta;}}_{2}k}{w}_{13}+h_{42}{e}^{j{\mathrm{\&theta;}}_{3}k}{w}_{14}\\ p_{22}=h_{12}{e}^{j{\mathrm{\&theta;}}_{0}k}{w}_{21}+h_{22}{e}^{j{\mathrm{\&theta;}}_{1}k}{w}_{22}+h_{32}{e}^{j{\mathrm{\&theta;}}_{2}k}{w}_{23}+h_{42}{e}^{j{\mathrm{\&theta;}}_{3}k}{w}_{24}\end{array}$ (formula 11)

When the data is sent for the first time, the data transmitted by the STBC at the second moment reaches a receiving end, and the signal-to-noise ratio is the same as the calculation method of the first moment:

when retransmission is needed, the method is performed according to the prior art, and the signal-to-noise ratio after combination is as follows:

$\left[\begin{array}{c}{\hat{s}}_1\\ {\hat{s}}_2\end{array}\right]\left[\begin{array}{cc}2{\left|p_{11}\right|}^2+2{\left|p_{12}\right|}^2+2{\left|p_{21}\right|}^2+2{\left|p_{22}\right|}^2& 0\\ 0& 2{\left|p_{11}\right|}^2+2{\left|p_{12}\right|}^2+2{\left|p_{21}\right|}^2+2{\left|p_{22}\right|}^2\end{array}\right]\&times;\left[\begin{array}{c}{s}_1\\ {\mathrm{<figure-callout\; id="2"\; label="s"\; filenames="S2008100406503E00032.png,S2008100406503E00041.png"\; state="\{\{state\}\}">s</figure-callout>}}_2\end{array}\right]+\left[\begin{array}{c}{\mathrm{<figure-callout\; id="1"\; label="n"\; filenames="S2008100406503E00012.png"\; state="\{\{state\}\}">n</figure-callout>}}_1+{\mathrm{<figure-callout\; id="1"\; label="n"\; filenames="S2008100406503E00012.png"\; state="\{\{state\}\}">n</figure-callout>}}_1^{\&prime;}\\ {\mathrm{<figure-callout\; id="2"\; label="n"\; filenames="S2008100406503E00032.png,S2008100406503E00041.png"\; state="\{\{state\}\}">n</figure-callout>}}_2+{\mathrm{<figure-callout\; id="2"\; label="n"\; filenames="S2008100406503E00032.png,S2008100406503E00041.png"\; state="\{\{state\}\}">n</figure-callout>}}_2^{\&prime;}\end{array}\right]$

when retransmission is needed, negation is performed on data allocated to two antennas of the four antennas, taking negation performed on the second antenna and the fourth antenna as an example, negation performed on any two antennas is possible, and the principle is the same and is not described again;

during retransmission, the data transmitted by the STBC at the first time arrives at a receiving end, and the signal-to-noise ratio is as follows:

${\mathrm{<figure-callout\; id="1"\; label="r"\; filenames="S2008100406503E00012.png"\; state="\{\{state\}\}">r</figure-callout>}}_1=H\&times;D\&times;W\&times;S$

$=\left[\begin{array}{cccc}{h}_{11}& h_{21}& h_{31}& h_{41}\\ h_{12}& h_{22}& h_{32}& h_{42}\end{array}\right]\left[\begin{array}{cccc}{e}^{j{\mathrm{\&theta;}}_{0}k}& & & 0\\ & -e^{j{\mathrm{\&theta;}}_{1}k}& & \\ & & e^{j{\mathrm{\&theta;}}_{2}k}& \\ 0& & & -e^{j{\mathrm{\&theta;}}_{3}k}\end{array}\right]\&times;\left[\begin{array}{cc}{w}_{11}& w_{21}\\ w_{12}& w_{22}\\ w_{13}& w_{23}\\ w_{14}& w_{24}\end{array}\right]\&times;\left[\begin{array}{c}{s}_1\\ {\mathrm{<figure-callout\; id="2"\; label="s"\; filenames="S2008100406503E00032.png,S2008100406503E00041.png"\; state="\{\{state\}\}">s</figure-callout>}}_2\end{array}\right]$

$=\left[\begin{array}{cccc}{h}_{11}{e}^{j{\mathrm{\&theta;}}_{0}k}& -h_{21}{e}^{j{\mathrm{\&theta;}}_{1}k}& h_{31}{e}^{j{\mathrm{\&theta;}}_{2}k}& {-h}_{41}{e}^{j{\mathrm{\&theta;}}_{3}k}\\ h_{12}{e}^{j{\mathrm{\&theta;}}_{0}k}& {-h}_{22}{e}^{j{\mathrm{\&theta;}}_{1}k}& h_{32}{e}^{j{\mathrm{\&theta;}}_{2}k}& {-h}_{42}{e}^{j{\mathrm{\&theta;}}_{3}k}\end{array}\right]\&times;\left[\begin{array}{cc}{w}_{11}& w_{21}\\ w_{12}& w_{22}\\ w_{13}& w_{23}\\ w_{14}& w_{24}\end{array}\right]\&times;\left[\begin{array}{c}{s}_1\\ {\mathrm{<figure-callout\; id="2"\; label="s"\; filenames="S2008100406503E00032.png,S2008100406503E00041.png"\; state="\{\{state\}\}">s</figure-callout>}}_2\end{array}\right]$

$=\left[\begin{array}{cc}{p}_{11}^{\&prime;}& p_{12}^{\&prime;}\\ p_{21}^{\&prime;}& p_{22}^{\&prime;}\end{array}\right]\&times;\left[\begin{array}{c}{s}_1\\ {\mathrm{<figure-callout\; id="2"\; label="s"\; filenames="S2008100406503E00032.png,S2008100406503E00041.png"\; state="\{\{state\}\}">s</figure-callout>}}_2\end{array}\right]$

wherein, $\begin{array}{c}{p}_{11}^{\&prime;}=h_{11}{e}^{j{\mathrm{\&theta;}}_{0}k}{w}_{11}-h_{21}{e}^{j{\mathrm{\&theta;}}_{1}k}{w}_{12}+h_{31}{e}^{j{\mathrm{\&theta;}}_{2}k}{w}_{13}-h_{41}{e}^{j{\mathrm{\&theta;}}_{3}k}{w}_{14}\\ p_{12}^{\&prime;}=h_{11}{e}^{j{\mathrm{\&theta;}}_{0}k}{w}_{21}-h_{21}{e}^{j{\mathrm{\&theta;}}_{1}k}{w}_{22}+h_{31}{e}^{j{\mathrm{\&theta;}}_{2}k}{w}_{23}-h_{41}{e}^{j{\mathrm{\&theta;}}_{3}k}{w}_{24}\\ p_{21}^{\&prime;}=h_{12}{e}^{j{\mathrm{\&theta;}}_{0}k}{w}_{11}-h_{22}{e}^{j{\mathrm{\&theta;}}_{1}k}{w}_{12}+h_{32}{e}^{j{\mathrm{\&theta;}}_{2}k}{w}_{13}-h_{42}{e}^{j{\mathrm{\&theta;}}_{3}k}{w}_{14}\\ p_{22}^{\&prime;}=h_{12}{e}^{j{\mathrm{\&theta;}}_{0}k}{w}_{21}-h_{22}{e}^{j{\mathrm{\&theta;}}_{1}k}{w}_{22}+h_{32}{e}^{j{\mathrm{\&theta;}}_{2}k}{w}_{23}-h_{42}{e}^{j{\mathrm{\&theta;}}_{3}k}{w}_{24}\end{array}$ (formula 12)

During retransmission, the data transmitted by the STBC at the second moment reaches the receiving end, the signal-to-noise ratio is the same as the calculation method of the first moment, and the signal-to-noise ratio after combination is as follows:

$\left[\begin{array}{c}{\hat{s}}_1\\ {\hat{s}}_2\end{array}\right]=\left[\begin{array}{cc}{\left|p_{11}\right|}^2+{\left|p_{12}\right|}^2+{\left|p_{21}\right|}^2+{\left|p_{22}\right|}^2+{\left|p_{11}^{\&prime;}\right|}^2+{\left|p_{12}^{\&prime;}\right|}^2+{\left|p_{21}^{\&prime;}\right|}^2{+\left|p_{22}^{\&prime;}\right|}^2& 0\\ 0& {\left|p_{11}\right|}^2+{\left|p_{12}\right|}^2+{\left|p_{21}\right|}^2+{\left|p_{22}\right|}^2+{\left|p_{11}^{\&prime;}\right|}^2{+\left|p_{12}^{\&prime;}\right|}^2+{\left|p_{21}^{\&prime;}\right|}^2{+\left|p_{22}^{\&prime;}\right|}^2\end{array}\right]\&times;\left[\begin{array}{c}{s}_1\\ {\mathrm{<figure-callout\; id="2"\; label="s"\; filenames="S2008100406503E00032.png,S2008100406503E00041.png"\; state="\{\{state\}\}">s</figure-callout>}}_2\end{array}\right]+\left[\begin{array}{c}{\mathrm{<figure-callout\; id="1"\; label="n"\; filenames="S2008100406503E00012.png"\; state="\{\{state\}\}">n</figure-callout>}}_1+{\mathrm{<figure-callout\; id="1"\; label="n"\; filenames="S2008100406503E00012.png"\; state="\{\{state\}\}">n</figure-callout>}}_1^{\&prime;}\\ {\mathrm{<figure-callout\; id="2"\; label="n"\; filenames="S2008100406503E00032.png,S2008100406503E00041.png"\; state="\{\{state\}\}">n</figure-callout>}}_2+{\mathrm{<figure-callout\; id="2"\; label="n"\; filenames="S2008100406503E00032.png,S2008100406503E00041.png"\; state="\{\{state\}\}">n</figure-callout>}}_2^{\&prime;}\end{array}\right]$

according to the combined snr obtained by combining the equations 11 and 12, the embodiment can obtain more diversity gains, and other items are similar, so that more diversity gains can be obtained after combination, thereby improving the utilization rate of the wireless spectrum resources. The above operations such as spatial multiplexing, spatial diversity, precoding and the like, which are performed before the data allocated to the antennas are transmitted, may be selected from one or all of the operations, and do not affect the implementation of the present invention.

If more than two transmissions are required, they can be made according to the following table, which is preferred, although it is possible to reverse them in other ways.

During the first retransmission, negating the distributed data of the second antenna and the fourth antenna;

during second retransmission, negating the distributed data of the second antenna and the third antenna;

and in the third retransmission, the distributed data of the second antenna and the fourth antenna are inverted.

The first retransmission is a second transmission; the second retransmission is the third transmission; the third retransmission is a fourth transmission. Each column in the table below is otherwise permutable and its nature is not changed and remains a preferred embodiment. If more than four transmissions are required, the four operations in the table below may be used as a loop to invert more transmissions.

TABLE 1

Sixth, an embodiment of the present invention further provides a data sending apparatus, a schematic structural diagram of which is shown in fig. 9, where the data sending apparatus includes: a data allocation unit 901, a data negation unit 902, and an antenna group 903;

a precoding unit 904, configured to perform precoding processing on the data that needs to be retransmitted; the precoding processing can refer to the precoding method in the fifth embodiment. The precoding process may be completed before the antenna group 903 transmits the allocated data;

a data allocation unit 901, configured to allocate data to be retransmitted to antennas of antenna group 903; the antenna group 903 consists of at least two antennas;

a data negation unit 902, configured to negate data allocated to a part of antennas in the antenna group 903;

and an antenna group 903, configured to send the allocated data.

When the antenna group in the sixth embodiment includes two antennas, the implementation manner may be:

a pre-coding unit, configured to perform pre-coding processing on the data to be retransmitted;

the data allocation unit is used for allocating data needing to be retransmitted to the two antennas of the antenna group;

a data negation unit, configured to negate data allocated to one antenna in the antenna group;

and the antenna group is used for transmitting the allocated data.

When the antenna group in the sixth embodiment includes four antennas, the implementation manner may be:

a pre-coding unit, configured to perform pre-coding processing on the data to be retransmitted;

the data allocation unit is used for allocating data needing to be retransmitted to the four antennas of the antenna group;

a data negation unit, configured to negate data allocated to two antennas in the antenna group; of course, the data allocated to one antenna or three antennas of the antenna group may be inverted;

and the antenna group is used for transmitting the allocated data.

Seventh, an embodiment of the present invention further provides a data sending apparatus, a schematic structural diagram of which is shown in fig. 10, where the data sending apparatus includes: a spatial diversity unit 1001, a data allocation unit 1002, a data negation unit 1003, an antenna group 1004, and a precoding unit 1005;

a precoding unit 1005, configured to perform precoding processing on the data that needs to be retransmitted; the precoding process may be completed before the antenna group 1004 transmits the allocated data;

a spatial diversity unit 1001, configured to perform spatial diversity processing on the data that needs to be retransmitted before the retransmission data is transmitted.

A data allocation unit 1002, configured to allocate data to be retransmitted to antennas of the antenna group 1004; antenna group 1004 is comprised of at least two antennas; a data allocating unit 1002, configured to allocate the spatially diversity-processed data to be retransmitted to antennas of the antenna group 1004 if the spatial diversity processing is completed before the allocation;

a data negation unit 1003, configured to negate data allocated to a part of antennas in the antenna group 1004; a data negation unit 1003, configured to negate data that is allocated to a part of antennas in the antenna group 1004 and is subjected to the spatial diversity processing, if the spatial diversity processing is completed before the allocation;

and antenna group 1004 for transmitting the allocated data. The distributed data is data which is subjected to space diversity processing and needs to be retransmitted.

An eighth embodiment of the present invention further provides a data sending apparatus, a schematic structural diagram of which is shown in fig. 11, including: a spatial multiplexing unit 1101, a data allocation unit 1102, a data negation unit 1103, an antenna group 1104, and a precoding unit 1105;

a precoding unit 1105, configured to perform precoding processing on the data that needs to be retransmitted; the precoding process may be completed before the antenna group 1104 transmits the allocated data;

a spatial multiplexing unit 1101, configured to perform spatial multiplexing on the data that needs to be retransmitted before the retransmission data is sent.

A data allocation unit 1102, configured to allocate data to be retransmitted to antennas of antenna group 1104; antenna group 1104 is comprised of at least two antennas; if the spatial multiplexing processing is completed before the allocation, a data allocation unit 1102 is configured to allocate data to be retransmitted, which is subjected to spatial multiplexing processing, to antennas of an antenna group 1104;

a data negation unit 1103, configured to negate data allocated to a part of antennas in the antenna group 1104; if the spatial multiplexing is completed before the allocation, a data negation unit 1103 is configured to negate data that is allocated to a part of antennas in the antenna group 1104 and is spatially multiplexed;

and antenna group 1104 for transmitting the allocated data. The distributed data is data which is subjected to spatial multiplexing processing and needs to be retransmitted;

in the embodiment of the device, if the two transmission channels are the same, the combined signal-to-noise ratio is the average value of the square sum of the modulus of each channel, and is the complete diversity gain; when the correlation of the front and back transmission channels is small, the embodiment can still obtain large diversity gain; thereby improving the utilization rate of wireless spectrum resources.

Ninth, an embodiment of the present invention further provides a communication system, including: data transmission means 1201 and data reception means 1202; please refer to fig. 12:

a data sending device 1201, configured to perform precoding processing on data that needs to be retransmitted; allocating data to be retransmitted to an antenna group, wherein the antenna group at least comprises two antennas; negating data allocated to a part of antennas of the antenna group; the allocated data is sent to the data receiving apparatus 1202 through the antenna group.

A data receiving device 1202, configured to receive the allocated data sent by the data sending device 1302, and perform merging processing on the data received twice before and after.

When the data transmission device includes two antennas, the method includes:

the data sending device is used for carrying out precoding processing on the data needing to be retransmitted; distributing data to be retransmitted to two antennas of an antenna group; negating data allocated to one of the two antennas; and sending the distributed data to a data receiving device through the two antennas.

When the data transmission device comprises four antennas, the method comprises the following steps:

the data sending device is used for carrying out precoding processing on the data needing to be retransmitted; distributing data to be retransmitted to four antennas of an antenna group; negating data allocated to two of the four antennas, where, of course, the data allocated to one or three antennas of the antenna group may also be negated here; and sending the distributed data to a data receiving device through the antenna group.

The system can combine the data distributed by one antenna of the at least two antennas by taking the inverse of the data distributed by the antenna, and the combination processing after receiving can be combined according to the embodiment of the method, so that more diversity gains are realized after combination, and the utilization rate of the wireless spectrum resources is improved.

It will be understood by those skilled in the art that all or part of the steps in the method for implementing the above embodiments may be implemented by hardware that is related to instructions of a program, and the program may be stored in a computer-readable storage medium, and when executed, the program includes the following steps:

distributing data to be retransmitted to two antennas of an antenna group;

negating data allocated to one of the two antennas;

and transmitting the distributed data through an antenna group consisting of the two antennas.

The storage medium mentioned above may be a read-only memory, a magnetic or optical disk, etc.

The foregoing describes in detail a data retransmission method and a data transmission apparatus provided in an embodiment of the present invention, and a specific example is applied in the present disclosure to explain the principle and the implementation of the present invention, and the description of the foregoing embodiments is only used to help understanding the method and the core idea of the present invention; meanwhile, for a person skilled in the art, according to the idea of the present invention, there may be variations in the specific embodiments and the application scope, and in summary, the content of the present specification should not be construed as a limitation to the present invention.

Claims (16)

1. A method for retransmitting data, comprising:

carrying out precoding processing on data needing to be retransmitted;

allocating data to be retransmitted to antennas of an antenna group, wherein the antenna group comprises at least two antennas;

negating data allocated to a part of antennas in the antenna group; the negation is to take the distributed data as a whole to be negative;

and transmitting the allocated data through the antenna group.

2. The method of claim 1, wherein before sending the allocated data, further comprising:

performing cyclic delay diversity processing on the data needing to be retransmitted; and/or

And carrying out space-time block code processing on the data needing to be retransmitted.

3. The method of claim 1, wherein before sending the allocated data, further comprising:

and performing space-frequency block code processing on the data needing to be retransmitted.

4. A method according to any one of claims 1-3, characterized in that the set of antennas comprises two antennas;

negating the data allocated to the portion of antennas in the antenna group comprises:

and negating the data distributed by one antenna of the two antennas.

5. The method of claim 4, wherein inverting the data allocated to one of the two antennas comprises:

if the data sent by the two previous antennas are positive, taking the negative of the data distributed by one antenna in the two antennas; or

And if the data sent by the two previous antennas are negative, the data distributed by one of the two antennas is positive.

6. The method of claim 4, wherein inverting the data allocated to one of the two antennas comprises:

if the data sent by the first two antennas is positive, and the data sent by the second antenna is negative, the data distributed by the first antenna is negative; or positive for the data allocated by the second antenna.

7. The method of claim 1, wherein the antenna group comprises four antennas;

negating the data allocated to the portion of antennas in the antenna group comprises:

and negating the data distributed by two antennas in the four antennas.

8. The method of claim 7, wherein inverting the data allocated to two of the four antennas comprises:

during the first retransmission, negating the distributed data of the second and fourth antennas during the first transmission;

during second retransmission, negating the distributed data of the second and third antennas during the first retransmission;

and in the third retransmission, negating the distributed data of the second antenna and the fourth antenna in the second retransmission.

9. A data transmission apparatus, comprising:

a pre-coding unit, configured to perform pre-coding processing on data to be retransmitted;

the data allocation unit allocates data to be retransmitted to the antennas of an antenna group, wherein the antenna group comprises at least two antennas;

a data negation unit, configured to negate data allocated to a part of antennas in the antenna group; the negation is to take the distributed data as a whole to be negative;

and the antenna group is used for transmitting the allocated data.

10. The apparatus of claim 9, wherein the antenna group comprises two antennas;

negating data allocated to a portion of antennas in the antenna group comprises:

and negating the data distributed by one antenna in the antenna group.

11. The apparatus of claim 9, wherein the antenna group comprises four antennas;

negating data allocated to a portion of antennas in the antenna group comprises:

and negating the data distributed by the two antennas in the antenna group.

12. The apparatus of any one of claims 9 to 11, further comprising:

and a space diversity unit, configured to perform space diversity processing on the data to be retransmitted before the retransmission data is sent.

13. The apparatus of any one of claims 9 to 11, further comprising:

and a spatial multiplexing unit, configured to perform spatial multiplexing on the data to be retransmitted before the allocated data is sent.

14. A wireless communication system comprising a data transmitting apparatus communicably connected to a data receiving apparatus,

the data sending device is used for carrying out precoding processing on the data needing to be retransmitted; allocating data to be retransmitted to an antenna group, wherein the antenna group comprises at least two antennas; negating data allocated to a part of antennas in the antenna group; the negation is to take the distributed data as a whole to be negative; and sending the distributed data to a receiving device through the antenna group.

15. The system of claim 14, wherein the antenna group comprises two antennas,

the data sending device is used for carrying out precoding processing on the data needing to be retransmitted; distributing data to be retransmitted to two antennas of an antenna group; negating data allocated to one of the two antennas; and sending the distributed data to a receiving device through the two antennas.

16. The system of claim 14 wherein the set of antennas comprises four antennas,

the data sending device is used for carrying out precoding processing on the data needing to be retransmitted; distributing data to be retransmitted to four antennas of an antenna group; negating data distributed by two antennas in the four antennas; and sending the distributed data to a receiving device through the four antennas.

Images