WO2014040428A1

WO2014040428A1 - Power distribution method and system for multiple-input multiple-output system

Info

Publication number: WO2014040428A1
Application number: PCT/CN2013/076538
Authority: WO
Inventors: 孙德福
Original assignee: 华为技术有限公司
Priority date: 2012-09-14
Filing date: 2013-05-31
Publication date: 2014-03-20
Also published as: CN103686975A; CN103686975B

Abstract

Disclosed are a power distribution method and system for a multiple-input multiple-output system. The method comprises: acquiring a channel matrix between a transmitting end and a receiving end, and the noise power of the receiving end; and according to the acquired channel matrix, the noise power of the receiving end, and the number of code words and the number of layers in a code word, allowing to employ inter-code word water-filling power distribution between at least two code words, wherein the water-filling power level corresponding to a code word with a large number of layers is greater than the water-filling power level corresponding to a code word with a small number of layers. In this way, the present invention can effectively improve the system capacity of a multiple-code word multiple-input multiple-output system, thereby improving the throughput performance of the system.

Description

The present invention claims to be submitted to the Chinese Patent Office on September 14, 2012, the application number is 201210341660.7, and the invention name is "a multi-input and multi-output system power allocation method and system" Priority of Chinese Patent Application, the entire contents of which is incorporated herein by reference. TECHNICAL FIELD The present invention relates to the field of communications technologies, and in particular, to a power distribution method and system for a multiple input multiple output system.

BACKGROUND With the development of wireless communication technologies, people's requirements for communication speed and quality are also constantly increasing. How to realize high-speed data transmission with high spectrum utilization has become an urgent problem to be solved. Multiple-Input Multiple-Output (MIMO) technology based on multi-antenna transmission and multi-antenna reception can greatly increase the capacity of bandwidth-limited channels by making full use of the rich multipath scattering environment of the wireless channel.

MIMO technology is mainly space-time signal processing, that is, the combination of time domain and spatial domain for signal processing by using multiple antennas distributed in space. MIMO technology uses 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, and spatial multiplexing gain and spatial diversity gain are obtained to increase the data rate and reduce the bit error rate. . MIMO technology can effectively utilize random fading and possible multipath propagation, and transform the multipath influencing factors existing in the traditional communication system into enhancement factors that are beneficial to the user's communication performance, so that the occupied signal bandwidth can be increased without additional Under the premise, the performance of wireless communication will be doubled.

In an actual MIMO system, at present, the MIMO system mainly uses a power allocation method based on inter-layer water injection. The basic principle is to control the transmission power according to the channel condition, and the subchannel with good channel condition allocates more power, and the channel difference is sub-channel. The channel allocates less power and maximizes system capacity. Assume that the system layer is the total transmit power as the power allocation based on the inter-layer water injection criterion. The formula is as follows:

Where Α represents the power value assigned by the i-th layer, σ ² is the noise power, and ^ is the channel gain corresponding to the first layer;

Is a constant. Therefore, the layer with the higher value of ^ allocates more power, that is, the layer with higher signal-to-noise ratio allocates more power.

The inventor of the present application found in long-term development that a single codeword is transmitted on multiple layers.

In the ΜΙΜΟ system, if the water injection power allocation method is used, since the SNR (signal-to-noise ratio) between the layers is not balanced, one codeword can only use a low-order MCS (modulation coding scheme) close to the low SNR value, and Several layers with slightly higher SNR in the codeword cannot achieve the maximum transmission capacity, resulting in greater difference in interlayer SNR within a single codeword, and the lowest SNR value is further reduced, thereby reducing the MCS of the entire codeword. Therefore, for real-time MIMO systems with codeword-to-multilayer transmission, system throughput is reduced by using a power allocation method based on inter-layer water injection. As a result, the ideal system throughput performance is not available.

SUMMARY OF THE INVENTION The present invention provides an implementation manner of a power allocation method and system for a multiple input multiple output system, which can effectively improve the throughput of a multiple input multiple output system.

An aspect of the present application is: Providing a power allocation method for a multiple input multiple output system, comprising: acquiring a channel matrix between a transmitting end and a receiving end, and receiving noise power at a receiving end; and obtaining, according to the obtained channel matrix, the receiving end noise The power and the number of codewords and the number of layers in the codeword enable power to allocate power between the codewords between at least two codewords, wherein the coded power level corresponding to the number of codewords is greater than the codeword with fewer layers Corresponding water injection power level. The method includes: causing the code words having the same number of layers to have the same water injection power level, and making the power allocated to the code word with a high signal to noise ratio greater than the power allocated to the code word having a low signal to noise ratio.

among them, Thereafter, the method further includes: redistributing the power allocated to each of the codewords in each layer of the codeword such that the signal-to-noise ratios of the layers in the codeword are the same or within a preset difference. After the step, the method further includes: determining whether a signal to noise ratio of the at least two codewords exceeds a preset threshold signal to noise ratio, and if the signal to noise ratio of the codeword exceeds a preset threshold signal to noise ratio, releasing the allocated Exceeding the part of the power of the preset threshold signal-to-noise ratio, and compensating the released power to a codeword whose signal-to-noise ratio is lower than a preset threshold signal-to-noise ratio, so that the signal noise of the codeword after the power is released The ratio does not exceed a preset threshold signal to noise ratio, and the signal to noise ratio of each layer in the compensated codeword is the same or within a preset difference, wherein the threshold signal to noise ratio is to maximize the codeword The signal to noise ratio corresponding to the order of the modulation coding scheme.

The method further includes: setting the threshold signal to noise ratio and saving. The method includes: redistributing power allocated to each of the codewords in layers within the codeword such that when the number of layers in the codeword is fixed, the total power allocated by the layer of the codeword is fixed , the k

The total power is: where P _T represents the total power allocated by the layer of the codeword, represents the power allocated by the i-th layer, and k represents the number of layers of the system.

Another aspect of the present application is: providing a multiple input and multiple output system, comprising: an obtaining module, a first power allocation module, wherein: an acquiring module, configured to acquire a channel matrix between a transmitting end and a receiving end, and a noise power of the receiving end, Transmitting, by the first power distribution module, the channel matrix, the noise power of the receiving end, and the first power distribution module, The number of layers is such that the power is allocated between the at least two code words by using the water injection power between the code words, wherein the water injection power level corresponding to the code word with a large number of layers is greater than the water injection power level corresponding to the code word with a small number of layers.

The first power allocation module is specifically configured to enable the codewords with the same number of layers to have the same water injection power level, and to allocate a power of a codeword with a higher signal to noise ratio to a code that is assigned to a lower signal to noise ratio. The power of the word.

The system further includes: a second power allocation module, configured to: after the power is allocated between the at least two codewords, the power allocated to each of the codewords is in the code The layers within the word are redistributed so that the signal-to-noise ratios of the layers within the codeword are the same or are preset Within the difference.

The system further includes: a power compensation module, configured to determine, after the power allocated to each of the codewords is reassigned in layers in the codeword, whether a signal to noise ratio of the at least two codewords exceeds a preset threshold signal to noise ratio, if the signal to noise ratio of the codeword exceeds a preset threshold signal to noise ratio, releasing the allocated portion of the power exceeding the preset threshold signal to noise ratio, and releasing the Power compensation to a codeword whose signal-to-noise ratio is lower than a preset threshold SNR, so that the signal-to-noise ratio of the codeword after releasing power does not exceed a preset threshold SNR, and the compensated codeword The signal-to-noise ratio of each layer is the same or within a preset difference, wherein the threshold signal-to-noise ratio is a signal-to-noise ratio corresponding to the order of the maximum modulation and coding scheme of the codeword.

The system further includes: a setting module, configured to preset the threshold signal to noise ratio and save.

Wherein the power allocated to each of the codewords is redistributed in layers within the codeword such that when the layers within the codeword are fixed, the total power allocated by the layers of the codewords is fixed. The total power is:

Where _{τ τ} represents the total power allocated by the layer of the codeword, represents the power allocated by the i-th layer, and k represents the number of layers of the system.

In the above technical solution, by using the water injection power allocation method between code words, the system capacity of the multi-codeword multiple input and multiple output system can be effectively improved, thereby improving the throughput performance of the system.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a flow chart of an embodiment of a multi-system power allocation method according to the present application; FIG. 2 is a flowchart of another embodiment of a multi-system power allocation method according to the present application; Schematic diagram of the mode;

Figure 4 is more than this application

A schematic structural diagram of an embodiment of a system power distribution device.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to FIG. 1 , an embodiment of a power allocation method for multiple input and multiple output systems of the present application includes: Step S101 : Obtain a channel matrix and a noise power at a receiving end between a transmitting end and a receiving end; In the embodiment of the present application, the meaning of the layer is the same as the "layer" in the 3GPP TS 36.211 protocol, and the layer in the embodiment of the present application may also be referred to as a stream. The meaning of the codeword is the same as the "codeword" in the 3GPP TS 36.211 protocol.

The channel matrix refers to a matrix formed by the channel between the transmitting end and the receiving end of the MIMO system. By acquiring the channel matrix, some channel state information can be obtained, and the eigenvalues of the channel matrix are obtained through processing.

At least two code words may be included in the system, for example, two code words may be included, or multiple code words may be included, and each code word corresponds to multiple layers;

Step S102: According to the channel matrix of the transmitting end to the receiving end and the noise power of the receiving end, the work is based on the channel matrix of the transmitting end to the receiving end and the noise power of the receiving end, the number of code words and the number of layers in the codeword, and the water injection power between the code words is used. The allocation method distributes power between at least two codewords. The water injection power level corresponding to the code word with a large number of layers is greater than the water injection power level corresponding to the code word with a small number of layers. For example, the water injection power level corresponding to each code word is proportional to the number of layers included in the code word.

When the number of layers of the codeword is equal, the water injection power level corresponding to the codeword is equal. At this time, the signal-to-noise ratio of the codeword is obtained, and the signal-to-noise ratio of the codeword is compared, and the signal-to-noise ratio is allocated according to the signal-to-noise ratio. The power of the high codeword is greater than the power assigned to the codeword with a low signal to noise ratio. For example, if the SNR of the first codeword is higher than the SNR of the second codeword, the first codeword allocates more power than the second codeword; for example, there are three codewords, if the SNR of the three codewords is: The first codeword>the second codeword>the third codeword, the power allocation is: first codeword>second codeword>third codeword, if the SNR of the three codewords is: first code Word>third codeword>second codeword, then the power allocation is: first codeword>third codeword>second codeword, etc., and so on. That is, according to the high to low of the codeword SNR, the power allocated to each codeword is also from large to small.

Through the above embodiments, it can be understood that the implementation of the present application allocates power between code words by using a water injection power allocation method, thereby effectively improving the system capacity of the multi-codeword multiple input and multiple output system, thereby improving the throughput performance of the system. .

Referring to FIG. 2, in another implementation manner of the multi-input and multi-output system power allocation method of the present application, the method includes:

Step S201: Obtain a channel matrix between the transmitting end and the receiving end, and receive noise power at the receiving end; Step S202: According to the channel matrix of the transmitting end to the receiving end, and the noise power and code of the receiving end The number of words and the number of layers in the codeword, such that the power is allocated between the at least two code words using the water injection power between the code words;

Step S203: Reassign the power allocated to each codeword to each layer in the codeword; after completing the power allocation between the codewords, the inter-layer value of the power in the multiple codewords may be in the error. A difference within the range that can be allowed. Of course, in practical applications, equal power allocation can also be performed between layers of a plurality of codewords. At the same time, when the number of layers in multiple codewords is fixed

Timing, the total power allocated by the layers of all codewords is fixed, written as: where Ρ _τ represents the total power allocated by the layers of all codewords, represents the power allocated by the i-th layer, and k represents the number of layers of the system.

Step S204: releasing a codeword release power whose signal to noise ratio exceeds a preset threshold signal to noise ratio, and compensating the released power to a layer of a codeword whose signal to noise ratio is lower than a preset threshold signal to noise ratio;

After the above power allocation, the SNR of a certain codeword may be high or even exceed the preset threshold SNR, and the order of the MCS will not increase any more. To this end, a threshold SNR needs to be set in advance and saved. The threshold SNR of the embodiment of the present application is the SNR corresponding to the maximum MCS order of the codeword. Of course, in practical applications, users can also customize the threshold SNR according to their needs. For example, an SNR slightly higher or lower than the threshold SNR of the embodiment of the present application can be set as the threshold SNR. You can set the same SNR as the threshold SNR of each codeword, or you can set different threshold SNRs for different codewords. Therefore, when the SNR of the codeword exceeds the preset threshold SNR, a part of the power on the codeword exceeding the preset threshold SNR may be released, so that the SNR value of the codeword after releasing the power does not exceed the preset threshold SNR. And releasing the released power to each layer corresponding to the codeword whose SNR does not reach the preset threshold SNR, so that the low SNR codeword MCS

The SNR is the same or within the preset difference.

The setting of the threshold SNR here may be set before any of the above steps occur, and the present application is not limited as long as the threshold SNR is set before the power compensation is performed in step S204.

In the following, the power allocation method of the present application is further described by taking the case where the number of code words of the multiple input and multiple output system is 2 as an example: Assuming that the channel matrix is H, the eigenvalue corresponding to the channel matrix H is 4 ^≥ 4 ^{≥ ≥} 4 ^{> Q} , assuming that the number of layers is k and the number of code words is 2, the first m layers are mapped to the first code word, and the last km layers are Map to the second codeword. The corresponding transmit power of the i-th layer is Ρ'·, assuming that the total transmit power is satisfied:

The P _T =∑P _t constraints are as follows:

i=\

K-\

m =■

Wherein, if it is an even number, ― 2 , is an odd number, ― 2 , σ ² is the noise power at the receiving end. In this embodiment, the constraint condition of the same SNR (equalization) of each layer in a single codeword is used, and the extreme value of the above condition is used. Problem, using Lagrange multiplier method, order

Among them, it is satisfied after the SNR equalization process between Lagrange:

Therefore, it is only necessary to find A and ^A to find the work value assigned by other layers. (2) can be expressed as:

its

In the middle, , the power A, A of the first layer and the kth layer are separately biased: After

Since the total power is limited, the following formula holds:

Wrong by formula! The reference source was not found. , formula error! The reference source was not found. Available:

So by the formula error! Not found Available A, Ρ>

First, second

PCWl

Among them, , are the power injection levels of two code words. If the number of layers of two codewords is k-m=m, the total power allocated by the first and second codewords is:

The power values assigned by other layers are: Then the SN corresponding to the two codewords

By mistake! Reference source not found

. It can be seen that, therefore, CW2 is the same codeword with the same number of layers, and the codeword with high signal-to-noise ratio allocates more power.

If the SNR of the first codeword is higher than the SNR of the second codeword, the SNR after the power allocation of the first codeword may be high in the power allocation process, and when the SNR is higher than a certain value, the MCS is no longer It will continue to improve, so too high SNR will not increase throughput. In order to further optimize the throughput, the threshold SNR is preset and saved. Here, the threshold SNR is the signal-to-noise ratio corresponding to the maximum MCS order of the codeword. Determining whether the SNR of the first codeword exceeds a preset threshold SNR. If the SNR of the first codeword exceeds a preset threshold SNR after the first power allocation, the power allocated by the first codeword may be reduced, and the SNR will be released. The power is added to the layer corresponding to the second codeword to improve the SNR of the second codeword, and the MCS of the second codeword is correspondingly increased, thereby improving the total throughput.

Set the threshold SNR value: SNH— threshold. In this embodiment, the threshold SNR is the signal-to-noise ratio corresponding to the maximum MCS order of the codeword. However, in practical applications, when threshold SNR is set, the threshold SNR can also be customized as needed. The same SNR can be set as the threshold SNR for two codewords. Of course, different threshold SNRs can be set for the two codewords respectively. Assume that the power released by the i-th layer is A, in order to ensure that several layers of the first codeword release power, SNR

^ Ρ, =丁 A

At the same time, the wrong way! The reference source was not found. Can be derived: Preiease _ ^ σ * SN,R _ t "h "resh'~ol-d (16) The total power of the second codeword is:

P accept

Accept

Let the power on each layer of the two codewords be A

_O accept _ ^ ^accept —,, ' ^accept _ ^accept _ 1 _O acce _P t _ „ release corpse — Z Pi ^{= w} iPk ^> Pk = _ corpse = _

Therefore, the newly injected power values of the layers of the second codeword are:

p _pt , _{m<i ≤ k} (20) According to the power allocation calculation described above, there may be a case where the power allocated to the second codeword is calculated to be a negative value, but in practice, such a situation is unlikely to occur. Therefore, when the power of the second codeword is calculated to be a negative value, the power can be transmitted only on the first codeword, and the power can be equally distributed on each layer of the first codeword, so that the first After all the layers of the codeword are allocated power, the SNRs of the layers in the first codeword are equal or within a preset difference, and the sum of the powers allocated by the layers is equal to the total power. It is also possible to perform equal power allocation on each layer of the first codeword and to ensure that the sum of the powers allocated by the layers of the first codeword is equal to the total power. Or when the calculated power of the second codeword is negative, power redistribution is not performed, and power is allocated according to the system default mode.

The above formula and power allocation are described in detail only for the case where the number of codewords is 2. It can be understood from the above description that the water injection power distribution between code words in the present application has a certain correlation with the water injection power level, the number of layers in the codeword, and the noise power at the receiving end. In addition, in the case where there are a plurality of codewords, the power distribution of the codewords also satisfies the principle of power allocation with the number of codewords being two, and the corresponding formula calculation is also applicable, and will not be described here.

Referring to FIG. 3, a schematic structural diagram of an embodiment of a multiple input multiple output system according to the present application includes an obtaining module 31 and a first power distribution module 32, where:

The obtaining module 31 is configured to obtain a channel matrix between the transmitting end and the receiving end, and a noise power of the receiving end, and transmit the obtained channel matrix and the noise power of the receiving end to the first power distribution module; The first power distribution module 32 is configured to allocate power between the codewords between the at least two codewords according to the channel matrix, the noise power at the receiving end, the number of codewords, and the number of layers in the codeword, where the number of layers is The water injection power level corresponding to the plurality of code words is greater than the water injection power level corresponding to the code word with a small number of layers. When the number of layers of the codeword is the same, the codewords having the same number of layers have the same water injection power level, and the power allocated to the codeword having a high signal to noise ratio is greater than the power assigned to the codeword having a low signal to noise ratio.

With continued reference to FIG. 3, in another embodiment, the multiple input multiple output system of the present application further includes: a second power distribution module 33, configured to: after the first power distribution module 32 distributes power between at least two codewords Reassigning the power allocated to each of the codewords within layers of the codeword such that the layer SNRs within the codeword are the same or within a preset difference;

The second power allocation module 33 redistributes the power allocated to each of the codewords in layers within the codeword so that the SNRs of the respective layers within each codeword after the re-power allocation are the same or are preset Within the difference, when the number of layers in the codeword is fixed, the total merit of all layers allocated by the codeword

The rate is fixed, written as: where Ρ _τ represents the total power allocated by all layers of the codeword, indicating the power allocated by the i-th layer, and k represents the number of layers of the system;

With continued reference to FIG. 3, in another embodiment, the multiple input multiple output system of the present application further includes: a power compensation module 34 for enabling the power allocated to each of the codewords in the second power distribution module 33 After each layer in the word is allocated again, power compensation is performed: determining whether the SNR of at least two codewords exceeds a preset threshold SNR. If the SNR of the codeword exceeds a preset threshold SNR, the release is allocated to exceed the preset. The power of the codeword of the threshold SNR, and the released power is compensated to the codeword whose SNR is lower than the preset threshold SNR, so that the SNR of the codeword after releasing the power does not exceed the preset threshold SNR, and after compensation The SNR of each layer in the codeword is the same or within a preset difference. The threshold SNR of the embodiment of the present application is a signal-to-noise ratio corresponding to the order of the maximum modulation and coding scheme of the codeword. Of course, in practical applications, when threshold SNR is set, the SNR value can be customized as the threshold SNR according to needs. The same threshold can be set for different codewords. Different threshold SNR can also be set.

Continuing to refer to FIG. 3, in another embodiment, the multiple input multiple output system of the present application further includes: a setting module 35, configured to preset threshold SNR and save; The setting module 35 is configured to set the threshold SNR to be stored in the system. The threshold SNR of the embodiment of the present application is an SNR corresponding to the order of the maximum modulation coding scheme of the codeword. In practical applications, when setting the threshold SNR, you can also customize the SNR value as the threshold SNR as needed. At the same time, the same SNR can be set as the threshold SNR for different codewords, and different SNRs can be set as threshold SNRs for different codewords.

In addition, in another embodiment of the present application, a multi-input and multi-out system power distribution device is also provided. Referring to FIG. 4, the device includes: a transmitter 41, a receiver 42, a memory 43, and a processor 44. The transmitter 41 and the memory 43 are each electrically connected to the processor 44, and the transmitter 41 and the receiver 42 communicate via a wireless channel.

Both the transmitter 41 and the receiver 42 comprise a plurality of antennas, the transmitter 41 transmits signals through a plurality of antennas, the system comprises at least two code words, and the receiver 42 receives signals transmitted by the transmitter 41 through a plurality of antennas;

The processor 44 is configured to control the power to be allocated among the codewords and the codeword according to the channel matrix of the transmitter to the receiver, the noise power of the receiver, the number of codewords and the number of layers in the codeword obtained at the transmitter 41, and After the power allocation between the codewords and the layers in the codeword, when the SNR of the codeword exceeds the preset threshold SNR, the power on the codeword exceeding the preset threshold SNR is released, and the released power compensation Go to the corresponding layers in the codeword that does not reach the preset threshold SNR, and control the SNR of each layer in the power compensated codeword to be the same or within the preset difference. The SNR of each codeword for power allocation, the preset difference value, and the preset threshold SNR are stored in the memory 43.

With the above embodiments, the embodiments provided by the present application have advantages in that: by using the water injection power allocation method between code words, the system capacity of the multi-codeword multiple input and multiple output system can be effectively improved; The inter-layer power allocation method in the codeword is also used to perform inter-layer power allocation in the codeword, which can effectively improve the MCS order of the codeword, thereby improving the throughput of the system. In addition, by reducing the power of the high SNR codeword and compensating the released power to the low SNR codeword, the MCS order of the low SNR codeword is effectively improved, and the use efficiency of the system transmit power is effectively improved.

In the several embodiments provided in the present application, it should be understood that the disclosed apparatus and method may be implemented in other manners. For example, the device implementations described above are merely illustrative, for example, the division of the modules or units is only a logical function division, There may be additional ways of dividing the implementation, for example multiple units or components may be combined or integrated into another system, or some features may be omitted or not executed. In addition, the mutual coupling or direct coupling or communication connection shown or discussed may be an indirect coupling or communication connection through some interface, device or unit, and may be in an electrical, mechanical or other form.

The functional modules described as separate components may or may not be physically separated. The components displayed as the components may or may not be physical units, that is, may be located in one place, or may be distributed to multiple network units. . Some or all of the units may be selected according to actual needs to achieve the objectives of the present embodiment.

In addition, each functional module in each embodiment of the present application may be integrated into one processing unit, or each functional module may exist physically separately, or two or more functional modules may be integrated into one unit. The above integrated unit can be implemented in the form of hardware or in the form of a software functional unit.

The integrated unit, if implemented in the form of a software functional unit and sold or used as a standalone product, may be stored in a computer readable storage medium. Based on such understanding, the technical solution of the present application, in essence or the contribution to the prior art, or all or part of the technical solution may be embodied in the form of a software product stored in a storage medium. The instructions include a plurality of instructions for causing a computer device (which may be a personal computer, a server, or a network device, etc.) or a processor to perform all or part of the steps of the methods described in various embodiments of the present application. The foregoing storage medium includes: a U disk, a removable hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk or an optical disk, and the like, which can store program codes. .

The above description is only the embodiment of the present invention, and is not intended to limit the scope of the invention, and the equivalent structure or equivalent process transformation using the specification and the drawings of the present invention may be directly or indirectly applied to other related technologies. The scope of the invention is included in the scope of patent protection of the present invention.

Claims

Rights request

1. A multiple-input multiple-output system power allocation method, characterized by including:

Obtain the channel matrix between the transmitter and the receiver and the noise power of the receiver;

According to the obtained channel matrix, the noise power at the receiving end, the number of codewords, and the waterfilling power level corresponding to a codeword with a large number of codewords is greater than the waterfilling power level corresponding to a codeword with a small number of layers.

2. The method according to claim 1, wherein the step of allocating power between at least two codewords by using water injection power between codewords includes: making the codewords with the same number of layers have the same Waterfill the power level, and make the power allocated to codewords with a high signal-to-noise ratio greater than the power allocated to codewords with a low signal-to-noise ratio.

3. The method according to claim 1, characterized in that, after the step of allocating power between at least two codewords using inter-codeword water filling power, it further includes: allocating power to each of the codewords. The power is redistributed among each layer within the codeword, so that the signal-to-noise ratio of each layer within the codeword is the same or within a preset difference.

4. The method according to claim 3, characterized in that, after the step of redistributing the power allocated to each codeword to each layer within the codeword, it further includes:

Determine whether the signal-to-noise ratio of the at least two codewords exceeds a preset threshold signal-to-noise ratio. If the signal-to-noise ratio of any codeword exceeds the preset threshold signal-to-noise ratio, release the allocated signal that exceeds the preset threshold signal-to-noise ratio. This part of the power of the noise ratio is compensated to the codewords whose signal-to-noise ratio is lower than the preset threshold signal-to-noise ratio, so that the signal-to-noise ratio of the codewords after releasing the power does not exceed the preset threshold. The threshold signal-to-noise ratio, and the signal-to-noise ratio of each layer in the compensated codeword is the same or within a preset difference, where the threshold signal-to-noise ratio is to enable the codeword to reach the maximum order of the modulation and coding scheme corresponding to signal-to-noise ratio.

5. The method according to claim 4, further comprising: presetting the threshold signal-to-noise ratio and saving it.

6. The method according to claim 3, wherein the step of redistributing the power allocated to each codeword in each layer within the codeword includes: causing the power allocated to each codeword to be redistributed. The power of is redistributed among the layers within the codeword, so that when the number of layers within the codeword is fixed, the k

The total power allocated to the codeword layer is fixed, and the total power is: =∑, where P _τ represents represents the total power allocated by the layer of the codeword, represents the power allocated by the i-th layer, and k represents the number of layers of the system.

7. A multiple-input multiple-output system, characterized by including an acquisition module and a first power distribution module, wherein:

The acquisition module is used to obtain the channel matrix between the transmitting end and the receiving end and the noise power of the receiving end, and transmit the channel matrix and the noise power of the receiving end to the first power distribution module;

A first power allocation module configured to allocate power between at least two codewords using inter-codeword water injection power according to the acquired channel matrix, the receiving end noise power, the number of codewords, and the number of layers within the codeword. , where the water filling power level corresponding to a code word with a large number of layers is greater than the water filling power level corresponding to a code word with a small number of layers.

8. The system according to claim 7, wherein the first power allocation module is specifically configured to make the codewords with the same number of layers have the same water filling power level, and to allocate the codewords with a high signal-to-noise ratio to The power of a codeword is greater than the power allocated to a codeword with a low signal-to-noise ratio.

9. The system according to claim 7, wherein the device includes: after allocating the water injection power, the power allocated to each codeword is redistributed in each layer within the codeword, so that the codeword The signal-to-noise ratio of each layer is the same or within the preset difference.

10. The system according to claim 9, characterized in that the device includes: a power compensation module, configured to determine the power allocated to each codeword after redistributing it to each layer within the codeword. Whether the signal-to-noise ratio of at least two codewords exceeds the preset threshold signal-to-noise ratio. If the signal-to-noise ratio of any codeword exceeds the preset threshold signal-to-noise ratio, release the allocated signal-to-noise ratio that exceeds the preset threshold signal-to-noise ratio. This part of the power is compensated to the codewords whose signal-to-noise ratio is lower than the preset threshold signal-to-noise ratio, so that the signal-to-noise ratio of the codewords after releasing the power does not exceed the preset threshold signal-to-noise ratio. noise ratio, and the signal-to-noise ratio of each layer in the compensated codeword is the same or within a preset difference, where the threshold signal-to-noise ratio is the signal corresponding to the order of the maximum modulation and coding scheme that enables the codeword to reach noise ratio.

11. The system according to claim 10, characterized in that the device includes: a setting module, configured to pre-set the threshold signal-to-noise ratio and save it.

12. The system according to claim 9, characterized in that the power allocated to each codeword is redistributed in each layer within the codeword, so that when the number of layers in the codeword is fixed, the

The total power allocated by the layer of the codeword is fixed, and the total power is: , where P _τ represents the total power allocated by the layer of the codeword, represents the power allocated by the i-th layer, and k represents the number of layers of the system. .