CN110855328B - Differential spatial modulation method, device and storage medium based on antenna grouping - Google Patents

Abstract

The invention discloses a differential spatial modulation method, device and storage medium based on antenna grouping. According to two specific antenna activation matrices, corresponding symbols in the STBC coding matrix are respectively activated to form a TA-DSM transmission signal for transmission. Because the form of transmitting antenna grouping is adopted and the form of Alamouti coding is adopted in the STBC matrix; the present invention is suitable for any even number of transmitting antennas; in the case of the same number of transmitting antennas, there are more antenna activation matrices, thus obtaining higher Spectral efficiency; the present invention has the determinant characteristic that never disappears without any parameter or matrix optimization; the present invention has an orthogonal structure in the coding structure, so a low-complexity decoding algorithm can be used, and the decoding complexity. The simulation results show that under different system configurations, it has better bit error performance than other existing differential spatial modulation schemes that can obtain transmit diversity.

Description

A kind of differential spatial modulation method, device and storage medium based on antenna grouping

【Technical field】

The invention belongs to the technical field of transmit diversity transmission in a multi-antenna wireless communication system, and relates to a differential spatial modulation method, equipment and storage medium based on antenna grouping.

【Background technique】

The differential spatial modulation (Differential Spatial Modulation, DSM) transmission technology solves the problem of difficulty in accurately estimating channel information in the traditional spatial modulation (Spatial Modulation, SM) technology. However, DSM does not acquire transmit diversity and can only rely on receive diversity to combat channel fading.

In order to obtain transmit diversity, the literature proposes a differential transmission mechanism based on space-time block codewords, and gives a design idea to obtain transmit diversity in the differential transmission model. The literature gives a DSM algorithm in the case of dual antennas. Through codeword design, the algorithm obtains second-order transmit diversity without channel estimation, but its codeword parameters are many, and it is only suitable for transmitting antennas. A system with a number of 2. The literature proposes a differential spatial modulation (Dispersion Matrices based DSM, DM-DSM) scheme based on scattering matrix, which achieves transmit diversity at the expense of spectral efficiency. It cannot achieve linear decoding, so it has high decoding complexity. In the literature, a differential spatial modulation (Field Extension for DSM, FE-DSM) scheme based on algebraic domain extension that can obtain full diversity is also proposed. This scheme adopts an algebraic field extension method on the basis of DM-DSM. To construct a differential space-time code block to obtain full diversity, but its spectral efficiency is low due to the reduction of the number of codewords. The literature proposes a differential spatial transmission scheme STBC-DSM based on the Alamouti STBC structure. The codeword design of this scheme is relatively simple, it can obtain second-order transmit diversity, and supports low-complexity decoding, but its spectral efficiency is low.

[Content of the invention]

The object of the present invention is to overcome the shortcomings of the above-mentioned prior art, and to provide a differential spatial modulation method, device and storage medium based on antenna grouping. According to two specific antenna activation matrices, the corresponding symbols in the STBC matrix are activated respectively to form The TA-DSM sends the signal to transmit. The simulation results show that TA-DSM has better bit error performance than other existing schemes under different system configurations.

To achieve the above object, the present invention adopts the following technical solutions to realize:

A method for differential spatial modulation based on antenna grouping, comprising the following steps:

Step 1: Input B=B ₁ +B ₂ bits to the transmitter, where:

表示对x向下取整数，且取为2的p次幂，M_i表示第i个调制符号的阶数；对B个比特进行串并转换，其中B₁个比特用于从空间星座SC中

进行两次选择，分别选取天线激活矩阵A_up和A_down；B₂个比特用于选取n_T个M_i-PSK调制符号s_i；Among them, the symbol

Indicates that x is rounded down to the p-th power of 2, and M _i represents the order of the ith modulation symbol; serial-to-parallel conversion is performed on B bits, of which B ₁ bits are used to extract from the space constellation SC

Carry out two selections, and select the antenna activation matrices A _up and A _down respectively; B ₂ bits are used to select n _T M _i -PSK modulation symbols s _i ;

个Alamouti矩阵：Step 2: Generate according to modulation symbol _si

Alamouti matrices:

Then through matrix combination, symbol matrices corresponding to the two groups of antennas are generated:

Step 3: Generate the transmission codeword matrix C _k :

C _up = A _up X _up (5)

C _down =A _down X _down (6)

The further improvement of the present invention is:

In step 1, the activation state of the antenna is determined by the matrix A _up and A _down , and the specific method is as follows:

The spatial constellation SC is defined as the combination of all possible active antenna matrices:

为空间星座SC的尺寸，A_q为

维的天线激活矩阵。in,

is the size of the space constellation SC, and A _q is

dimensional antenna activation matrix.

The composition of the antenna activation matrix A _q includes the following steps:

维的矩阵

矩阵

中的元素仅包含0和1，且每行和每列仅包含一个非零元素；Step 1-1: Construct a

dimensional matrix

matrix

The elements in contain only 0s and 1s, and each row and column contains only one non-zero element;

进行角度旋转，旋转角度由下式确定：Step 2-2: Right

Perform angular rotation, the rotation angle is determined by the following formula:

in,

A terminal device includes a memory, a processor, and a computer program stored in the memory and executable on the processor, and the processor implements the steps of the above method when the processor executes the computer program.

A computer-readable storage medium storing a computer program, the computer program implementing the steps of the above method when executed by a processor.

Compared with the prior art, the present invention has the following beneficial effects:

Due to the special structure based on antenna grouping, the TA-DSM scheme in the present invention has the following advantages: 1. It is suitable for any even number of transmitting antennas; Because the DSM scheme has more antenna activation matrices than the STBC-DSM scheme, it can achieve higher spectral efficiency; 3. The TA-DSM scheme has a determinant that never disappears without any parameter or matrix optimization. (NVD) feature, which can ensure that the TA-DSM scheme can obtain second-order transmit diversity; 4. The TA-DSM scheme has an orthogonal structure in the coding structure, so a low-complexity decoding algorithm can be used, with very low decoding code complexity. The technical effect of the present invention can be compared with other existing differential spatial modulation schemes from four aspects: spectrum utilization rate, bit error performance, transmit diversity order and transmit antenna number.

1) Spectrum Utilization

If the number of transmit antennas configured in TA-DSM is n _T , and the modulation order of the ith symbol is M _i , its spectral efficiency is

The above-mentioned spectral efficiency is higher than other existing differential spatial modulation schemes that can achieve transmit diversity.

2) Error performance

Please refer to Figures 3 to 5 in the patent specification for the effect of improving the system performance by using the algorithm. The content of the present invention will be further described in detail below with reference to the accompanying drawings.

3) Meet NVD characteristics

After analysis, the coding gain of the TA-DSM scheme (that is, the minimum value of the determinant of the error matrix between any two TA-DSM codewords) is 2, so the proposed TA-DSM scheme has a rank and column that never disappears formula (NVD) characteristic, so that the second-order transmit diversity can be guaranteed.

4) Support flexible antenna number configuration

The TA-DSM system supports any even number of transmit antennas n _T .

【Description of drawings】

Fig. 1 is the structural block diagram of the TA-DSM transmitter of the present invention;

Figure 2 is a performance comparison diagram of a low-complexity decoding algorithm and an ML decoding algorithm;

Figure 3 shows the BER comparison of TA-DSM, STBC-DSM and DSM schemes at a spectral efficiency of 2.25bits/s/Hz;

Figure 4 is a BER comparison diagram of the TA-DSM and STBC-DSM schemes at a spectral efficiency of 1.33bits/s/Hz;

Fig. 5 is the BER comparison diagram under the spectral efficiency of 1.25bits/s/Hz of TA-DSM and STBC-DSM scheme.

【Detailed ways】

In order to make those skilled in the art better understand the solutions of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only The embodiments are part of the present invention, not all of the embodiments, and are not intended to limit the scope of the present disclosure. Furthermore, in the following description, descriptions of well-known structures and techniques are omitted to avoid unnecessarily obscuring the concepts disclosed in the present invention. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

Various structural schematic diagrams according to the disclosed embodiments of the present invention are shown in the accompanying drawings. The figures are not to scale, some details have been exaggerated for clarity, and some details may have been omitted. The shapes of various regions and layers shown in the figures and their relative sizes and positional relationships are only exemplary, and in practice, there may be deviations due to manufacturing tolerances or technical limitations, and those skilled in the art should Regions/layers with different shapes, sizes, relative positions can be additionally designed as desired.

In the context of the present disclosure, when a layer/element is referred to as being "on" another layer/element, it can be directly on the other layer/element or intervening layers/elements may be present therebetween. element. In addition, if a layer/element is "on" another layer/element in one orientation, then when the orientation is reversed, the layer/element can be "under" the other layer/element.

It should be noted that the terms "first", "second" and the like in the description and claims of the present invention and the above drawings are used to distinguish similar objects, and are not necessarily used to describe a specific sequence or sequence. It is to be understood that the data so used may be interchanged under appropriate circumstances such that the embodiments of the invention described herein can be practiced in sequences other than those illustrated or described herein. Furthermore, the terms "comprising" and "having" and any variations thereof, are intended to cover non-exclusive inclusion, for example, a process, method, system, product or device comprising a series of steps or units is not necessarily limited to those expressly listed Rather, those steps or units may include other steps or units not expressly listed or inherent to these processes, methods, products or devices.

Below in conjunction with accompanying drawing, the present invention is described in further detail:

The invention proposes a differential spatial modulation transmission scheme that can obtain transmit diversity, and designs a differential spatial modulation method based on the idea of transmitting antenna grouping, which is named as a TA-DSM (Twofold Antennas based Differential Spatial Modulation) scheme.

In the method of differential spatial modulation (Twofold Antennas based Differential Spatial Modulation, TA-DSM) based on the antenna grouping of the present invention, the input information bits are divided into two parts: the first part is used to select twice from the antenna activation matrix set; The second part is used to select symbols from the M-PSK constellation, which are further combined to be sent from the corresponding active antennas. The specific implementation steps are shown in FIG. 1 . Please refer to Fig. 3 to Fig. 5 for the improvement effect of the present invention on system performance.

Referring to FIG. 1 , the differential spatial modulation method based on antenna grouping of the present invention includes the following steps:

Step 1: TA-DSM modulation method

In a MIMO system with _nT transmit antennas, the _nT transmit antennas are divided into upper and lower two groups, each group contains _nT /2 antennas, and in each transmit period, the antennas in the two groups are activated The states are determined by the matrices A _up and A _down , respectively.

First, the Spatial Constellation (SC) is defined as the combination of all possible active antenna matrices:

为SC的尺寸，A_q为

维的天线激活矩阵。in,

is the dimension of SC, and A _q is

dimensional antenna activation matrix.

The composition process of _Aq is divided into two steps:

维矩阵

中的元素仅包含0和1，且每行和每列仅包含一个非零元素；Step 1: Construct a

dimensional matrix

The elements in contain only 0s and 1s, and each row and column contains only one non-zero element;

进行相应的角度旋转，旋转角度由下式确定：Step 2: Right

The corresponding angle rotation is performed, and the rotation angle is determined by the following formula:

in

天线选择矩阵集合中共包含6个元素，分别为：Taking the MIMO system with n _T =6 as an example, at this time

The antenna selection matrix set contains a total of 6 elements, which are:

The specific TA-DSM modulation algorithm consists of the following three steps:

Step 1: A total of B=B ₁ +B ₂ bits enter the transmitter, where:

表示对x向下取整数，且取为2的p次幂，M_i表示第i个调制符号的阶数。首先对B个比特进行串并转换，其中B₁个比特用于从SC中

进行两次选择，分别选取天线激活矩阵A_up和A_down；B₂个比特用于选取n_T个M_i-PSK调制符号s_i；symbol

Indicates that x is rounded down to an integer and is taken to the p-th power of 2, and M _i represents the order of the i-th modulation symbol. First perform serial-to-parallel conversion on B bits, of which B ₁ bits are used to convert from SC

Carry out two selections, and select the antenna activation matrices A _up and A _down respectively; B ₂ bits are used to select n _T M _i -PSK modulation symbols s _i ;

个Alamouti矩阵：The second step: generate according to the modulation symbol _si selected in the first step

Alamouti matrix:

Then through matrix combination, symbol matrices corresponding to the two groups of antennas are generated:

Step 3: Generate the final transmission codeword matrix C _k :

C _up = A _up X _up (7)

C _down =A _down X _down (8)

For the above steps, an example of the generation process of the transmission matrix C of the TA-DSM is given when the system parameters are N _t =6 and M=2.

Since N _t =6, the antenna activation matrix set as shown in formula (2) contains 6 elements in total; since M=2, the BPSK constellation set is Y={1,-1}.

At the transmitting end, an 11-bit serial data [0 0 1 0 0 0 1 1 0 0 1] enters the system. According to equations (3) and (4), B ₁ =5 and B ₂ =6. According to the encoding process shown in Figure 1, the first 5 data bits [0 0 1 0 0] are used to select two groups of antenna activation matrices:

The last 6 data bits [0 1 1 0 0 1] are used to select four BPSK modulation symbols: s ₁ =1, s ₂ =-1, s ₃ =-1, s ₄ =1, s ₅ =1 , s ₆ =-1, according to formula (5), the corresponding three Alamouti matrices are:

According to formula (6), it can be known that the modulation symbol matrix combinations X _up and X _down after grouping are:

According to equations (7)-(9), the final transmitted codeword matrix C can be obtained as

Step 2: The main advantages of the TA-DSM solution

1) Obtain high spectral efficiency

比特，而n_T个调制符号携带的信息为

比特，因而TA-DSM方案的频谱效率为According to the above design method, in the TA-DSM scheme, the information that the spatial dimension can carry is:

bits, and the information carried by n _T modulation symbols is

bits, so the spectral efficiency of the TA-DSM scheme is

The above-mentioned spectral efficiency is higher than the existing differential spatial modulation schemes that can achieve diversity.

2) Support flexible antenna number configuration

It can be known from the above design method that the TA-DSM system supports any even number of transmitting antennas n _T .

3) Meet NVD characteristics

After analysis, the coding gain of the TA-DSM scheme (that is, the minimum value of the determinant of the error matrix between any two TA-DSM codewords) is 2, so the proposed TA-DSM scheme has a rank and column that never disappears formula (NVD) characteristic, so that the second-order transmit diversity can be guaranteed.

4) Has a unitary matrix structure

In the proposed TA-DSM scheme, the transmission codeword matrix C is a unitary matrix, so as to satisfy the constraints of the differential transmission mechanism.

Step 3: The unitary matrix properties of the transmission matrix of TA-DSM

为了使得差分传输能够持续，必须保证传输矩阵C_k为酉矩阵，从而确保发射矩阵S_k中每时隙的发射功率守恒，否则系统发射功率将会趋于无限大或零，这在实际应用系统中是无法实现的。In the TA-DSM system model, set the initial transmit matrix

In order to make the differential transmission sustainable, it is necessary to ensure that the transmission matrix C _k is a unitary matrix, so as to ensure that the transmission power of each time slot in the transmission matrix S _k is conserved, otherwise the system transmission power will tend to be infinite or zero. cannot be achieved in.

For the convenience of description, the transmission matrix C _k carrying the modulation information is denoted as C(X,l,k), where X=[X ₁ ,...,X _P ] represents P Alamouti modulation symbol matrices in C; parameter l= [l ₁ ,l ₂ ,...,l _P ,θ _u ], where l _p , (1≤p≤P) denotes the antenna index used to transmit X _p-up in the upper half of the antenna group, and θ _u denotes the antenna selection matrix Rotation angle of A _up ; parameter k=[k ₁ , k ₂ ,...,k _P , θ _d ], where k _p , (1≤p≤P) represent the lower half antenna used to transmit X _p-down Antenna index, θ _d represents the rotation angle of the antenna selection matrix A _down .

From equations (7)-(9), it can be known that X _p-up will transmit in two consecutive time slots 2p-1 and 2p through the 1 _pth antenna in the upper half of the antenna group; X _p-down will be transmitted through the lower half of the group of antennas. Among the antennas, the k _pth antenna transmits in two consecutive time slots 2p-1 and 2p. Through the codeword construction process, it can be concluded that the N _t ×N _t -dimensional transmission matrix C has the following properties:

1) There are only two non-zero elements in any column, and for the 2p-1 column and the _2p column, the two non-zero elements are located in the _lpth row and the kth row, respectively;

2) There are only two non-zero elements in any row, and for the _lpth row and the kth row, the two nonzero elements are located in the _2p -1th column and the 2pth column;

3) The 2 × 2-dimensional submatrix consisting of the l _p , k _p rows and the 2p-1, 2p columns has the following form:

由性质1)和2)可知：Next, the proof of the unitary matrix property of C will be given. For any codeword matrix C(X,l,k), take the adjacent two columns C(2p-1) and C(2p),

From properties 1) and 2), it can be known that:

<C(2p-1),C(i)>=0 (11)

<C(2p),C(i)>=0 (12)

From property 3), it can be known that:

<C(2p-1),C(2p)>=0

<C(2p-1),C(2p-1)>=1 (13)

<C(2p),C(2p)>=1

It can be known from equations (11)-(13) that the transmission matrix C is a unitary matrix.

Step 4: Diversity of TA-DSM

二者之间的误差矩阵为Consider two different codewords C(X,l,k) and

The error matrix between the two is

The rank r(Δ) of Δ will be described in the following case by case.

且

Case 1:

and

二者之间至少存在一组Alamouti矩阵不相等，假设

则Δ的前两列可表示为：At this time, the antenna selection matrices of the two are exactly the same. In this case, due to

There is at least one set of Alamouti matrices that are not equal between the two, assuming that

Then the first two columns of Δ can be expressed as:

则

或

必然有：because

but

or

There must be:

That is, there is at least one second-order subformula of Δ that is not 0, so r(Δ)≥2.

且

(或

且

)Case 2:

and

(or

and

)

At this time, according to property 1), it can be known that there are at least four columns in Δ (two adjacent columns of two groups) that the activated antennas are not exactly the same. Assuming that the first four columns are different, combined with property 2), the first four columns in Δ are composed of l ₁ , l ₂ , k The 4×4-dimensional submatrix composed of ₁ ,k ₂ rows and the first four columns can be expressed as:

[g₁,g₂]＝[0,0]或

In formula (16) [f ₁ , f ₂ ]=[0,0] or

[g ₁ ,g ₂ ]=[0,0] or

(或

)Case 2.1:

(or

)

时，若

则由Δ_4×4的第1，4行和第1，3列组成的二阶子式when

when, if

Then the second-order subformula consisting of rows 1, 4 and columns 1, 3 of Δ _4×4

则由Δ_4×4的第1，4行和第2，3列组成的二阶子式like

Then the second-order subformula consisting of rows 1, 4 and columns 2, 3 of Δ _4×4

That is, there is at least one second-order subformula that is not 0 in Δ, so r(Δ)≥2.

且

Case 2.2:

and

In this case, equation (16) can be simplified to

Case 2.2.1: [f ₁ ,f ₂ ]=[0,0] or [g ₁ ,g ₂ ]=[0,0]

At this time, the second-order sub-formula composed of rows 3 and 4 and columns 2 and 3 in formula (17)

That is, there is at least one second-order subformula that is not 0 in Δ, so r(Δ)≥2.

且

Case 2.2.2:

and

At this time, the second-order sub-formula composed of rows 3 and 4 and columns 2 and 3 in formula (17) is:

且

因此式(18)右侧的表达式不为0。即Δ中至少存在一个不为0的二阶子式，因此r(Δ)≥2。It can be known from the value of θ in formula (1) that

and

Therefore, the expression on the right side of Equation (18) is not 0. That is, there is at least one second-order subformula that is not 0 in Δ, so r(Δ)≥2.

且

Case 3:

and

The proof process is the same as Case 2.

所提出的TA-DSM方案均具有永不消失的行列式(NVD)特性，这样则保证本发明可以获得二阶的发射分集。由此可见，TA-DSM方案无需做任何参数及矩阵优化就可以获得二阶发射分集。Based on the above situation, for any two different transmission matrices C(X,l,k) and

The proposed TA-DSM schemes all have the non-disappearing determinant (NVD) characteristic, which ensures that the present invention can obtain second-order transmit diversity. It can be seen that the TA-DSM scheme can obtain second-order transmit diversity without any parameter and matrix optimization.

Step 5: Signal detection of TA-DSM

In an n _T ×n _R MIMO system, assuming that the channel is quasi-static Rayleigh fading, in the kth transmission cycle, when the n _T ×n _T -dimensional TA-DSM signal is transmitted, the n _R ×n _T -dimensional TA-DSM signal is transmitted. The received signal can be expressed as

Y _k =HS _k +N _k (19)

While in the differential transmission mechanism

S _k =S _k-1 C _k

Y _k-1 =HS _k-1 +N _k-1

Y _k =HS _k +N _k

You can get:

Y _k =Y _k-1 C _k +(N _k -N _k-1 C _k ) (20)

Therefore, the maximum likelihood decoding expression of the transmission matrix to be detected is:

Step 6: Low-complexity decoding algorithm of TA-DSM

In the decoding process, all antenna activation matrix conditions are first traversed. When the antenna activation matrix is determined, the last two parameters of the codeword C _k can be determined: l=[l ₁ ,l ₂ ,...,l _P ,θ _u ] and k=[k ₁ ,k ₂ ,... , k _P , θ _d ]. Denote Y _k -Y _k-1 C _k in formula (21) as W, then the adjacent columns 2p-1 and 2p in W can be expressed as

According to the properties of the transmission matrix C _k , it can be known that the modulation symbols s _2p-1 and s _2p only affect the two columns W(2p-1) and W(2p), and these two columns are also independent of the other modulation signals, so it can be According to formula (22), the modulation symbols are decoupled in turn, avoiding the joint demodulation of all modulation symbols, thereby reducing the decoding complexity.

To sum up, when the parameters (l, k) are determined, the detection expression of the modulation symbol in the pth Alamouti matrix is:

Denote the P minimum norm values corresponding to formula (23) as a _p |(l, k) respectively, and then by comparing the corresponding minimum norm sums, the optimal solutions of l and k can be obtained. Therefore, the translation of C _k The code expression is

It should be pointed out that the low-complexity decoding algorithm proposed by the present invention utilizes the orthogonal structural characteristics of the codeword to independently decouple the modulation symbols, which does not reduce the bit error rate performance. 2 It can be seen that the decoding algorithm with reduced complexity of the present invention has the same bit error rate performance as that of the ML decoding algorithm.

Decoding complexity is measured by the number of real multipliers required to decode each bit of information. Table 1 shows the complexity comparison between the decoding algorithm with reduced complexity of the present invention and the ML decoding algorithm when n _R =2, M = 4, and in the case of configuring different numbers of transmit antennas n _T. It can be seen from Table 1 that compared with the ML decoding algorithm, the decoding algorithm proposed by the present invention greatly reduces the amount of decoding operations.

Table 1 Comparison of decoding complexity under different numbers of transmit antennas

Step 7: Simulation Experiment

In this section, Monte Carlo simulations of the bit error performance of the proposed TA-DSM algorithm are performed and compared with existing STBC-DSM schemes. In all simulation graphs, the horizontal axis represents the signal-to-noise ratio (SNR) at each receiving antenna, the vertical axis is the bit error rate (BER), and the number of receiving antennas in all simulations is set to n _R = 2, the performance Comparisons were made at an SNR value of ^10-5 .

Fig. 2 shows that when the number of transmit antennas n _T =6, the modulation order M ₁ =M ₂ =M ₃ =2, M ₄ =M ₅ =M ₆ =1, the TA-DSM scheme adopts the method of the present invention respectively. The proposed low-complexity decoding algorithm is compared with the BER curve when using ML decoding. It can be seen that the two have achieved consistent decoding performance, because in the low-complexity decoding algorithm proposed in the present invention, only the orthogonal characteristics brought by the codeword design are used to independently decouple the modulation symbols in pairs. detection, thereby reducing the decoding complexity, this process does not affect the detection performance.

Figure 3 shows the BER comparison of the TA-DSM scheme, the STBC-DSM scheme and the DSM scheme when the number of transmit antennas is configured n _T =4 and the system spectral efficiency is 2.25 bits/s/Hz. As can be seen from Figure 3, due to the acquisition of transmit diversity, with the increase of signal-to-noise ratio, the performance of TA-DSM algorithm is improved faster than that of DSM algorithm without transmit diversity; TA-DSM and STBC-DSM have similar performance, which is When n _T = 4, the number of transmitting antennas is small, and the number of combinations of antenna activation matrices in the TA-DSM algorithm is not significantly improved. Therefore, in order to achieve the same spectral efficiency, TA-DSM is similar to STBC-DSM in modulation order. , the bit error rate performance is not much improved.

In Figures 4 and 5, the BER curves of the proposed TA-DSM scheme and the existing STBC-DSM scheme under two different spectral efficiencies are compared, respectively. It can be seen from the figure that the performance of TA-DSM is significantly better than that of STBC-DSM, because when n _T is large, the spatial dimension of the TA-DSM scheme carries more modulation information, and a lower modulation order can be used. The same spectral efficiency as STBC-DSM can be achieved, thus achieving better bit error rate performance. It can be seen from Figure 4 that when n _T =6 and the system spectral efficiency is 1.33bits/s/Hz, the performance of TA-DSM is about 4dB better than that of STBC-DSM; it can be seen from Figure 5 that when n _T =8, the spectrum When the efficiency is 1.25bits/s/Hz, the performance of TA-DSM is about 2dB better than that of STBC-DSM.

It can be seen from the simulation experiments in Figures 3 to 5 that the TA-DSM scheme has obvious performance advantages over the existing STBC-DSM scheme and DSM scheme. It should be pointed out that in the simulation results of the literature [6], it can be seen that the STBC-DSM scheme has performance advantages compared with the existing FE-DSM and PHD-DSM schemes, so the TA-DSM scheme proposed by the present invention There are several differential spatial modulation schemes that can achieve transmit diversity with performance advantages.

If the modules/units integrated in the terminal device of the present invention are implemented in the form of software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the present invention can implement all or part of the processes in the methods of the above embodiments, and can also be completed by instructing relevant hardware through a computer program. The computer program can be stored in a computer-readable storage medium, and the computer When the program is executed by the processor, the steps of the foregoing method embodiments can be implemented. Wherein, the computer program includes computer program code, and the computer program code may be in the form of source code, object code, executable file or some intermediate form, and the like. The computer-readable medium may include: any entity or device capable of carrying the computer program code, a recording medium, a USB flash drive, a removable hard disk, a magnetic disk, an optical disc, a computer memory, a read-only memory (ROM, Read-Only Memory), Random Access Memory (RAM, Random Access Memory), electric carrier signal, telecommunication signal and software distribution medium, etc. It should be noted that the content contained in the computer-readable media may be appropriately increased or decreased according to the requirements of legislation and patent practice in the jurisdiction, for example, in some jurisdictions, according to legislation and patent practice, the computer-readable media Electric carrier signals and telecommunication signals are not included.

The above content is only to illustrate the technical idea of the present invention, and cannot limit the protection scope of the present invention. Any changes made on the basis of the technical solution according to the technical idea of the present invention shall fall within the scope of the claims of the present invention. within the scope of protection.

Claims (5)

1. a differential spatial modulation method based on antenna grouping, is characterized in that, comprises the following steps: Step 1: Input B=B ₁ +B ₂ bits to the transmitter, where:

Among them, the symbol

Indicates that the integer is rounded down to x, and it is taken to the p power of 2,

is the size of the space constellation SC, M _i represents the order of the i-th modulation symbol; serial-to-parallel conversion is performed on B bits, of which B ₁ bits are used to extract from the space constellation SC

Carry out two selections, and select the antenna activation matrices A _up and A _down respectively; B ₂ bits are used to select n _T M _i -PSK modulation symbols s _i , where n _T is the number of transmitting antennas; Step 2: Generate according to modulation symbol _si

Alamouti matrix:

Then through matrix combination, symbol matrices corresponding to the two groups of antennas are generated:

Step 3: Generate the transmission codeword matrix C _k : C _up = A _up X _up (5) C _down =A _down X _down (6)

2. The method for differential spatial modulation based on antenna grouping according to claim 1, characterized in that, in step 1, the antenna activation state is determined by matrices A _up and A _down , and the specific method is as follows: The spatial constellation SC is defined as the combination of all possible active antenna matrices:

in,

is the size of the space constellation SC, and A _q is

dimensional antenna activation matrix. 3. The method for differential spatial modulation based on antenna grouping according to claim 2, wherein the formation of the antenna activation matrix A _q comprises the following steps: Step 1-1: Construct a

dimensional matrix

matrix

The elements in contain only 0s and 1s, and each row and column contains only one non-zero element; Step 2-2: Right

Perform angular rotation, the rotation angle is determined by the following formula:

in,

4. A terminal device, comprising a memory, a processor, and a computer program stored in the memory and running on the processor, wherein the processor implements the computer program as claimed in the claims 1 or 2 or 3 the steps of the method. 5. A computer-readable storage medium storing a computer program, wherein when the computer program is executed by a processor, the steps of the method according to claim 1 or 2 or 3 are implemented.

Images