CN102710567A - Part judgment method in interference elimination technology for multiple-input multiple-output (MIMO) wireless communication receiver - Google Patents

Abstract

The invention provides a part judgment method in an interference elimination technology for a multiple-input multiple-output (MIMO) wireless communication receiver. The part judgment method comprises the following steps of (1) setting a threshold, performing part judgment on a judgment statistical magnitude, and thus obtaining a part judgment signal; and (2) reconstructing the part judgment signal obtained in the step (1), and eliminating interference according to the reconstructed signal, wherein in the process of reconstructing the part judgment signal, the signal is reconstructed according to the part judgment signal by adopting the conventional hard judgment reconstruction method; and in the process of eliminating the interference of the reconstructed signal, the interference is eliminated according to the signal reconstructed from the part judgment signal by adopting the conventional hard judgment interference elimination method. The MIMO interference elimination is improved; slight complexity is increased; the advantages of simplicity and feasibility of the conventional MIMO interference elimination method are kept; and under the condition that slight complexity and slight calculation amount are increased, the performance of the MIMO wireless communication receiver is also improved.

Description

Partial Judgment Method in Interference Cancellation Technology of MIMO Wireless Communication Receiver

technical field

The invention relates to a multi-antenna wireless communication transmission method, which belongs to the technical field of wireless communication.

Background technique

With the development of network technology, people's requirements for accessing the network are also constantly increasing. High-speed access to the Internet anytime and anywhere has become an important demand for more and more people. Wireless communication technology is the main supporting technology that can meet the above needs of people. Therefore, broadband wireless communication technology has developed rapidly in recent years. Spectrum efficiency has always been the research focus of wireless communication technology. In recent years, the multiple-input multiple-output (Multiple-Input Multiple-Output, hereinafter referred to as MIMO) technology based on multi-antenna technology at both ends of the transceiver has a spectrum that cannot be achieved by traditional single-antenna technology. Efficiency has received widespread attention. MIMO-OFDM is a combination of MIMO and Orthogonal Frequency Division Multiplexing (OFDM) based on cyclic prefix (Cyclic Prefix, CP) technology and single carrier frequency domain equalization (Single Carrier with Frequency Domain Equalization, SC-FDE) technology And MIMO-SCFDE will become the main supporting technology for future broadband wireless communication physical layer transmission.

MIMO utilizes the uncorrelated characteristics of channel gains between different antennas in a rich multipath wireless propagation environment to obtain high channel capacity, thereby improving the spectrum utilization and reliability of the entire system.

In the MIMO receiver, the receiver adopting the linear equalization method uses an equalization matrix to multiply the received signal vector to complete the equalization of the received signal. There are two commonly used linear equalization methods, namely zero forcing (Zero Forcing, ZF) equalization and minimum mean square error (Minimum Mean Square Error, MMSE) equalization.

判决后得到4个比特b₁b₂b₃b₄，其中同相分量a判决后对应b₁b₂,正交分量b判决后对应b₃b₄。星座图如附图2所示。对同相分量共进行两次判决：The QAM (Quadrature Amplitude Modulation, Quadrature Amplitude Modulation) modulation method is widely used in many standards, such as IEEE802.11, 3GPP-LTE, WLAN and so on. MIMO systems, including MIMO narrowband systems, MIMO-OFDM systems and MIMO-SCFDE systems, all widely use QAM modulation to achieve modulation and demodulation. In the process of QAM demodulation, the implementation method of using hard judgment is as follows: the in-phase component and quadrature component of the signal to be judged are judged separately, and the transmission information bits are generally obtained by comparing the in-phase component or quadrature component with the judgment threshold multiple times, and then The information bits are transformed into decision signals according to the bit mapping method of the constellation diagram. Taking 16QAM demodulation as an example, the signal to be judged (also called the decision statistic) is a+bj, where

Four bits b ₁ b ₂ b ₃ b ₄ are obtained after the judgment, wherein the in-phase component a corresponds to b ₁ b ₂ after the judgment, and the quadrature component b corresponds to b ₃ b ₄ after the judgment. The constellation diagram is shown in Figure 2. A total of two judgments are made on the in-phase component:

The first judgment threshold is D ₁ , D ₁ =0, and the judgment method is:

The second judgment threshold is D ₂ , D ₂ =2, and the judgment method is:

The quadrature component is judged in the same way as the in-phase component, and b ₃ b ₄ is obtained after judgment. For example, the bit mapping method of the constellation diagram shown in Fig. 2 is that when the information bit is 0101, it is transformed into a decision signal -1-j.

Receivers based on sequential interference suppression (Successive Inference Cancellation, SIC) use good interference suppression technology to greatly reduce the interference between different layers, and their performance is generally significantly better than that of decorrelation receivers based only on linear equalization. A typical representative of SIC-based MIMO receivers is the BLAST (Bell Laboratories Layered Space-Time Architecture) receiver proposed by Bell Laboratories G Foschini.

The detection process of the V-BLAST detection algorithm based on the stepwise pseudo-inverse is as follows: before detecting the signal, the layers of the detected signal are sorted according to certain criteria, and the sorting principle is based on the Signal to Noise Ratio (SNR) or the SNR (Signal to Interference and Noise Ratio, SINR) size sorting, first detect the layer with a large SNR (or SINR), and each layer of signal is detected, and the signals of other layers are treated as interference, and then the interference of the current layer signal to the undetected signal layer is removed . The signal detected earlier has an influence on the signal detected later, so a certain bit error diffusion will be caused. Sorting by certain criteria can reduce error spread. ZF equalization or MMSE equalization may be used to remove the interference of the current layer signal on the undetected signal layer.

The following describes the implementation process of the V-BLAST detection algorithm based on the stepwise pseudo-inverse. In this process, ZF equalization is used to remove the interference of the current layer signal on the undetected signal layer:

H ₁ =H

fori=1,...,N _T

其中 $G_i={[g_i^{\left(1\right)},g_i^{\left(2\right)},\·\·\·,g_i^{\left(N_T\right)}]}^T$ (1)

in $G_i={[g_i^{\left(1\right)},g_i^{\left(2\right)},\·\&Center\; Dot;\&Center\; Dot;,g_i^{\left(N_T\right)}]}^T$

(2) $k_i=\arg \underset{j}{\min }{\left|\right|g_i^{\left(j\right)}\left|\right|}^2$

(3) ${\mathrm{the\; y}}_{k_i}=g_i^{\left(k_i\right)}\·x_i$

(4) ${\hat{c}}_{k_i}=\mathrm{D.}\left[{\mathrm{the\; y}}_{k_i}\right]$

(5) $x_{i+1}=x_i-h_i^{\left(k_i\right)}\·{\hat{c}}_{k_i},$ in $h_i=[h_i^{\left(1\right)},h_i^{\left(2\right)},\·\·\·,h_i^{\left(N_T\right)}]$

(6) Set the k _i column of H _i to zero to get the update matrix H _i+1

end

表示矩阵的伪逆，

表示第k_i层发送信号的估计值（也就是按欧氏距离最接近的星座点信号）,D[·]表示由判决统计量到判决信号的变换过程。步骤(2)依据一定准则选出待检测层；步骤(3)(4)实现了对待检测层符号检测的过程，其中步骤(4)是量化过程，用于消除噪声干扰；步骤(5)实现了消除当前层受到已检测层符号干扰的过程,其中

实现对已检测层符号的重构。Among them, i represents the number of iterations, (·) _i represents the matrix obtained in the i-th iteration, (·) ^(j) represents the jth row or jth column of the matrix, (·) ^T represents the transpose of the matrix,

represents the pseudoinverse of the matrix,

Indicates the estimated value of the transmitted signal at the _kith layer (that is, the closest constellation point signal according to the Euclidean distance), and D[·] indicates the transformation process from the decision statistic to the decision signal. Step (2) selects the layer to be detected according to certain criteria; Step (3) (4) realizes the process of symbol detection of the layer to be detected, wherein step (4) is a quantization process for eliminating noise interference; step (5) realizes In order to eliminate the process of the current layer being interfered by the symbols of the detected layer, where

Implements reconstruction of detected layer symbols.

In the MIMO-OFDM system detection algorithm, because each subchannel of the MIMO-OFDM system can be regarded as a narrowband MIMO channel, the V-BLAST detection algorithm of the narrowband MIMO system can be applied to the signal detection of the MIMO-OFDM system subchannel by subchannel. In the MIMO-SCFDE system detection algorithm, based on the principle of V-BLAST for MIMO signal layered detection, a block V-BLAST detection algorithm for the MIMO-SCFDE system has been proposed. The method is as follows: at the MIMO receiving end, according to certain selection criteria The transmitted signal is equalized and detected in the frequency domain layer by layer. After each layer of signal detection is completed, the signal is transformed into the frequency domain, and then multiplied by the corresponding channel matrix, and then eliminated as interference from the signal to be detected, and then The signals of the next layer are detected in the same way until all the signals of the layers are detected.

The V-BLAST detection algorithm of the narrowband MIMO system, the BLAST detection algorithm of the MIMO-OFDM system, and the block V-BLAST detection algorithm of the MIMO-SCFDE system all perform hard judgment on the detected signal layer, and perform hard judgment on the signal obtained by the hard judgment. The reconstructed signal is obtained through reconstruction, and the reconstructed signal is further used for interference elimination.

The BLAST receiver proposed by G Foschini of Bell Labs, although its V-BLAST has received extensive attention from the academic community, has not been widely accepted by the industry due to its high complexity and sensitivity to channel measurement errors.

Chinese patent document CN102006250A discloses a "Turbo Enhancement Method for MIMO-SCFDE Wireless Communication Receiver", which enables this de-correlation receiver to maintain the advantages of simple structure and easy implementation, and enables MIMO-SCFDE wireless communication to receive Machine performance is improved.

In the MIMO communication system, it is customary to call the signal transmitted by a transmitting antenna a layer, and each layer of signal has N symbols, which can be represented by an N×1 dimensional matrix; different transmitting antennas correspond to different layers of transmitting signals, the first The signal transmitted by the i transmit antennas is called the i-th layer.

The Turbo enhancement method steps of the MIMO-SCFDE wireless communication receiver are as follows:

其中

是第i层的频域估计值，i＝1,2,…,N_T，

是第k个频域子信道的频域估计值，k＝0,1,…,N-1。(1) Cache the frequency-domain baseband signal R before equalization, take out the cached signal and perform linear equalization on it, and change the equalized signal back to the time domain. The time-domain signal is called a decision statistic, and a hard decision is made on the decision statistic. Obtain the information bits of each layer, and further obtain the frequency domain estimation signal of each corresponding layer symbol

in

is the estimated value in the frequency domain of the i-th layer, i=1,2,...,N _T ,

is the frequency-domain estimated value of the kth frequency-domain sub-channel, k=0,1,...,N-1.

是(1,…,N_T)的任意一个排列，N_T表示发射天线数；从步骤（1）得到的频域估计值

k＝0,1,…,N-1中取出第k₁层以外的其他各层符号的频域估计值，用来重构接收机接收到的第k₁层以外的其他各层发射信号的频域信号，

k＝0,1,…,N-1;i∈{1,2,…,N_T}是对接收机接收到的第i层发射信号的频域信号的重构，（·）^T表示矩阵或向量的转置；k＝0,1,…,N-1;i∈{1,2,…,N_T}是对接收机接收到的除第i层以外的N_T-1层发射信号的频域信号的重构；然后取出缓存的均衡前频域基带信号R，用缓存的信号减去接收机接收到的除第K₁层以外的其他N_T-1层发射信号重构的频域信号，即

k＝0,1,…,N-1；将得到的基带信号

左乘

得到

k＝0,1,…,N-1;K₁∈{1,2,…,N_T}；然后将第k₁层基带信号通过N点IFFT变换到时域，得到干扰消除后的判决统计量，再对该判决统计量进行硬判决，得到第k₁层的输出信息比特向量将

按发射端符号映射方式重新进行符号映射后变回到频域，用当前频域估计值更新原频域估计值

中的

用相同的方法处理第k₂层基带信号，直至

层基带信号，每次重构接收机接收到的当前层以外的其他各层发射信号的频域信号时，使用最新更新过的频域估计值

进行更新。(2) Turbo enhancement is performed on the frequency-domain estimated value of each layer of symbols. One enhancement of the frequency-domain estimated value of each layer of symbols is called a round of Turbo enhancement. According to the requirements for receiver performance and complexity, at least one Wheel Turbo Enhanced. Among them, the specific method of performing a round of Turbo enhancement on the frequency domain estimated value of each layer of symbols is as follows:

is any permutation of (1,…,N _T ), where N _T represents the number of transmitting antennas; the frequency-domain estimated value obtained from step (1)

From k=0,1,...,N-1, the frequency-domain estimated values of the symbols of other layers other than the _k1th layer are taken out, and used to reconstruct the transmitted signals of other layers other than the _k1th layer received by the receiver frequency domain signal,

k=0,1,…,N-1; i∈{1,2,…,N _T } is the reconstruction of the frequency domain signal of the i-th layer transmitted signal received by the receiver, (·) ^T represents the matrix or the transpose of a vector; k=0,1,…,N-1; i∈{1,2,…, _NT } is the weight of the frequency domain signal received by the receiver from the _NT -1 layer except the i-th layer Then take out the cached pre-equalized frequency-domain baseband signal R, and use the cached signal to subtract the reconstructed frequency-domain signal received by the receiver from other _NT -1 layer transmission signals except the _K1th layer, that is

k=0,1,...,N-1; the baseband signal to be obtained

multiply by left

get

k=0,1,…,N-1; K ₁ ∈{1,2,…, _NT }; then transform the baseband signal of layer k ₁ into the time domain through N-point IFFT, and obtain the decision statistics after interference cancellation , and then make a hard decision on the decision statistic to obtain the output information bit vector of the _k1th layer Will

Re-map the symbol according to the symbol mapping method of the transmitter and return to the frequency domain, and update the original frequency domain estimate with the current frequency domain estimate

middle

Use the same method to process the kth layer ₂ baseband signal until

When reconstructing the baseband signal of each layer other than the current layer received by the receiver, the latest updated frequency domain estimation value is used

to update.

Among them, H ^k is the channel matrix of the kth frequency domain sub-channel, expressed as

${\mathrm{<span\; class="notranslate">\; h</span>}}^{\mathrm{<span\; class="notranslate">\; k</span>}}<span\; class="notranslate">\; =</span>\left[\begin{array}{cccc}{\mathrm{<span\; class="notranslate">\; <figure-callout\; id="1"\; label="h"\; filenames="HDA00001615252000012.png,HDA00001615252000021.png"\; state="\{\{state\}\}">h</figure-callout></span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; 1</span>}}^{\mathrm{<span\; class="notranslate">\; <figure-callout\; id="1"\; label="k\; h"\; filenames="HDA00001615252000012.png,HDA00001615252000021.png"\; state="\{\{state\}\}">k</figure-callout></span><figure-callout\; id="1"\; label="k\; h"\; filenames="HDA00001615252000012.png,HDA00001615252000021.png"\; state="\{\{state\}\}">\; </figure-callout>}}& {\mathrm{<span\; class="notranslate">\; </span>}}_{}^{}{\mathrm{<span\; class="notranslate">h</span>}}_{\mathrm{<span\; class="notranslate">\; 1,2</span>}}^{\mathrm{<span\; class="notranslate">\; k</span>}}& <span\; class="notranslate">\; .</span><span\; class="notranslate">\; .</span><span\; class="notranslate">\; .</span>& {\mathrm{<span\; class="notranslate">\; <figure-callout\; id="1"\; label="h"\; filenames="HDA00001615252000012.png,HDA00001615252000021.png"\; state="\{\{state\}\}">h</figure-callout></span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; ,</span>{\mathrm{<span\; class="notranslate">\; N</span>}}_{\mathrm{<span\; class="notranslate">\; <figure-callout\; id="2"\; label="T\; k\; h"\; filenames="HDA00001615252000021.png"\; state="\{\{state\}\}">T</figure-callout></span><figure-callout\; id="2"\; label="T\; k\; h"\; filenames="HDA00001615252000021.png"\; state="\{\{state\}\}">\; </figure-callout>}}}^{\mathrm{<span\; class="notranslate">\; k</span>}}& \\ {}_{}^{}{\mathrm{<span\; class="notranslate">\; h</span>}}_{\mathrm{<span\; class="notranslate">\; 2,1</span>}}^{\mathrm{<span\; class="notranslate">\; <figure-callout\; id="2"\; label="k\; h"\; filenames="HDA00001615252000021.png"\; state="\{\{state\}\}">k</figure-callout></span><figure-callout\; id="2"\; label="k\; h"\; filenames="HDA00001615252000021.png"\; state="\{\{state\}\}">\; </figure-callout>}}& {\mathrm{<span\; class="notranslate">\; </span>}}_{}^{}{\mathrm{<span\; class="notranslate">h</span>}}_{\mathrm{<span\; class="notranslate">\; 2,2</span>}}^{\mathrm{<span\; class="notranslate">\; k</span>}}& <span\; class="notranslate">\; .</span><span\; class="notranslate">\; .</span><span\; class="notranslate">\; .</span>& {\mathrm{<span\; class="notranslate">\; <figure-callout\; id="2"\; label="h"\; filenames="HDA00001615252000021.png"\; state="\{\{state\}\}">h</figure-callout></span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}<span\; class="notranslate">\; ,</span>{\mathrm{<span\; class="notranslate">\; N</span>}}_{\mathrm{<span\; class="notranslate">\; T</span>}}}^{\mathrm{<span\; class="notranslate">\; k</span>}}\\ <span\; class="notranslate">\; .</span><span\; class="notranslate">\; .</span><span\; class="notranslate">\; .</span>& <span\; class="notranslate">\; .</span><span\; class="notranslate">\; .</span><span\; class="notranslate">\; .</span>& <span\; class="notranslate">\; .</span><span\; class="notranslate">\; .</span><span\; class="notranslate">\; .</span>& <span\; class="notranslate">\; .</span><span\; class="notranslate">\; .</span><span\; class="notranslate">\; .</span>\\ {\mathrm{<span\; class="notranslate">\; h</span>}}_{{\mathrm{<span\; class="notranslate">\; N</span>}}_{\mathrm{<span\; class="notranslate">\; R</span>}}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; 1</span>}}^{\mathrm{<span\; class="notranslate">\; k</span>}}& {\mathrm{<span\; class="notranslate">\; h</span>}}_{{\mathrm{<span\; class="notranslate">\; N</span>}}_{\mathrm{<span\; class="notranslate">\; R</span>}}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; 2</span>}}^{\mathrm{<span\; class="notranslate">\; k</span>}}& <span\; class="notranslate">\; .</span><span\; class="notranslate">\; .</span><span\; class="notranslate">\; .</span>& {\mathrm{<span\; class="notranslate">\; h</span>}}_{{\mathrm{<span\; class="notranslate">\; N</span>}}_{\mathrm{<span\; class="notranslate">\; R</span>}}<span\; class="notranslate">\; ,</span>{\mathrm{<span\; class="notranslate">\; N</span>}}_{\mathrm{<span\; class="notranslate">\; T</span>}}}^{\mathrm{<span\; class="notranslate">\; k</span>}}\end{array}\right]$

表示第j个发射天线与第i个接收天线间信道的第k个频域子信道复增益。where k∈{0,1,...,N-1}.

Indicates the complex gain of the k-th frequency-domain subchannel of the channel between the j-th transmit antenna and the i-th receive antenna.

Regardless of the Turbo enhancement method or the BLAST method, when the detected signal layer performs interference cancellation on the signal layer to be detected, the hard decision result of the detected signal layer is used to reconstruct the signal. It affects the quality of the reconstructed signal, thus affecting the effect of interference elimination.

Contents of the invention

Aiming at the error diffusion problem caused by the hard judgment in the MIMO wireless communication interference elimination method, the present invention proposes a partial judgment method in the MIMO wireless communication receiver interference elimination technology, which is based on the MIMO original hard judgment interference elimination method Improvements are made on the above, and the performance of the MIMO wireless communication receiver is further improved with less complexity and calculation.

The partial judgment method in the MIMO wireless communication receiver interference elimination technology of the present invention comprises the following steps:

(1) Set the threshold, make partial judgments on the judgment statistics, and obtain partial judgment signals; the specific process is:

部分判决过程中，需要对判决统计量r的同相分量和正交分量分别进行部分判决，判决统计量r的同相分量进行部分判决的过程如下：设判决统计量r同相分量第k个判决门限为D_k,k＝1,…,K,K为判决门限的总数，若判决统计量r的同相分量落在(D_k-ε,D_k+ε)区域内，不进行判决，保持原值；若判决统计量的同相分量落在(D_k-ε,D_k+ε)区域外，则按欧氏距离最近原则，判决为相应星座点同相分量对应的坐标值，判决统计量r的正交分量的部分判决过程与同相分量的部分判决过程相同；完成上述同相分量和正交分量的判决后，即得到部分判决信号

Set the threshold ε, and the value range of the threshold is 0<ε<1; let the decision statistic be expressed as r, make a partial decision on the decision statistic r, and obtain a part of the decision signal

In the partial judgment process, it is necessary to make partial judgments on the in-phase component and the quadrature component of the decision statistic r, and the process of making partial judgment on the in-phase component of the decision statistic r is as follows: Let the k-th decision threshold of the in-phase component of the decision statistic r be D _k ,k=1,...,K,K is the total number of decision thresholds, if the in-phase component of the decision statistic r falls within the (D _k -ε,D _k +ε) region, no decision is made and the original value is kept; If the in-phase component of the decision statistic falls outside the (D _k -ε, D _k +ε) area, then according to the principle of the closest Euclidean distance, the judgment is the coordinate value corresponding to the in-phase component of the corresponding constellation point, and the orthogonality of the decision statistic r The partial judgment process of the component is the same as the partial judgment process of the in-phase component; after completing the judgment of the above-mentioned in-phase component and quadrature component, the partial judgment signal is obtained

(2) Perform signal reconstruction on part of the judgment signals obtained in step (1), and use the reconstructed signals to eliminate interference; among them, the process of signal reconstruction on part of the judgment signals is to use part of the judgment signals to adopt the original hard judgment reconstruction method Carry out signal reconstruction; the process of reconstructing the signal for interference elimination is to use the signal reconstructed by part of the judgment signal to perform interference elimination by using the original hard judgment interference elimination method.

Aiming at the error diffusion problem caused by hard judgment, the present invention proposes a partial judgment method, which is improved on the MIMO original hard judgment interference elimination method, and maintains the advantages of the MIMO interference elimination method being simple and easy to implement. In the case of less complexity and calculation, the performance of the MIMO wireless communication receiver is further improved.

Description of drawings

Accompanying drawing 1 is the constellation diagram of modulation mode being 4QAM.

Accompanying drawing 2 is the constellation diagram of modulation mode being 16QAM.

Accompanying drawing 3 is the system block diagram that realizes part of the judgment method in the interference elimination technology of the MIMO-SCFDE wireless communication receiver of the present invention.

Accompanying drawing 4 is the comparison diagram of the bit error curve when using the IMT2000 (Vehicular A) channel MMSE equalization of the partial decision method in the interference elimination technology of the MIMO-SCFDE wireless communication receiver and the original hard decision method.

Accompanying drawing 5 is the comparison diagram of the bit error curve when using COST259 (UTx) channel MMSE equalization between the partial decision method in the MIMO-SCFDE wireless communication receiver interference elimination technology and the original hard decision method.

Among them: 1. MIMO-SCFDE transmitter processing module, 2. Radio frequency, intermediate frequency demodulation and baseband processing module, 3. Removing CP module, 4. FFT module (N points), 5. Linear equalization module, 6. IFFT module ( N points), 7, a partial judgment module, 8, a Turbo enhancement module using partial judgment results, and 9, an output module.

Detailed ways

The embodiment gives the simulation results of combining the partial decision method proposed by the present invention and the Turbo enhancement method in the MIMO-SCFDE wireless communication receiver.

The simulation parameters of this embodiment:

Simulation environment: MATLAB R2010a,

Total number of subchannels: N=1024,

CP length: 256,

Number of transmit antennas: 4,

Number of receiving antennas: 4,

Symbol mapping method: 16QAM,

Sampling rate: 20Mbps,

Threshold setting: ε=0.2,

Turbo enhanced rounds: 4 rounds,

The simulated average receiving signal-to-noise ratio range: SNR = 17 ~ 23 (dB).

The system that realizes the partial judgment method in the MIMO-SCFDE wireless communication receiver interference elimination technology of the present invention is as shown in accompanying drawing 3, and the effect of each module is as follows:

1. MIMO-SCFDE transmitter processing module: complete the baseband processing of MIMO-SCFDE signals, and transmit them after up-conversion.

2. RF, IF demodulation and baseband processing module: down-convert the received signal.

3. Go to CP module: remove cyclic prefix.

4. FFT module (N points): Transform the time-domain signal with the CP removed into the frequency domain.

5. Linear equalization module: linearly equalize the frequency domain signal by means of ZF equalization or MMSE equalization.

6. IFFT module (N points): Transform the equalized frequency domain signal into the time domain.

7. Partial judgment module: according to the method described in the present invention, partial judgment is performed on the time-domain signal.

8. Turbo enhancement module: perform Turbo enhancement on part of the judged signal.

9. Output module: output signal.

The specific implementation method of some judgments in the embodiment is as follows:

Taking 16QAM as an example, the threshold division is shown in Figure 2. Suppose the signal to be judged is a+bj, where a is the in-phase component, b is the quadrature component. Set the decision threshold as D _k , k=0,1,2. D ₀ =0, D ₁ =2, D ₂ =-2. The judgment method of the in-phase component part is:

where 0<ε<1. Quadrature component and in-phase component part of the judgment method is the same.

The threshold division method proposed by the invention can be extended to QAM modulation modes such as 4QAM and 64QAM.

Simulation results:

Accompanying drawing 4 has provided in the MIMO-SCFDE wireless communication system, adopts the bit error curve that the partial decision method that the present invention proposes and the Turbo enhancement method combine, in IMT2000 (Vehicular A) (referring to " TSI TR 125996V7.0.0UniversalMobile Telecommunications System ( UMTS); Spatial channel model for Multiple Input Multiple Output (MIMO) simulations", 2007) channel, and compared with the bit error rate curve of MMSE equalization and Turbo enhancement method using the original hard decision. As can be seen from accompanying drawing 4, the performance that the MIMO-SCFDE wireless communication receiver part decision method that the present invention proposes combines with the Turbo enhancement method is improved than the performance of the Turbo enhancement method that the MIMO-SCFDE wireless communication receiver adopts the original hard decision . IMT2000 (Vehicular A) channel, in the range of 10 ^-1 to 10 ^-2 , the performance of one round of Turbo enhancement method using partial decision method is improved by about 0.5dB compared with the performance of one round of Turbo enhancement method using the original hard decision method. The performance of the multi-round Turbo enhancement method of the method is about 1dB better than that of the original hard decision multi-round Turbo enhancement method.

Accompanying drawing 5 is given in the MIMO-SCFDE wireless communication system, adopts the bit error curve that the partial judgment method proposed by the present invention combines with the Turbo enhancement method, in COST259 (UTx) (referring to " 3GPP TR 25.943V6.0.03GPP channelmodels for Deployment evaluation", 2004) channel, and compared with the bit error rate curve of MMSE equalization and Turbo enhancement method using the original hard decision. Seen from accompanying drawing 5, COST259 (UTx) channel, in the range of 4 × 10 ^-2 to 4 × 10 ^-3 , the one-round Turbo enhancement method that adopts the partial decision method is better than the one-round Turbo enhancement method that adopts the original hard decision method. The performance improvement is about 0.5dB, and in the range of 10 ^-2 to 10 ^-3 , the performance of the multi-round turbo enhancement method using the partial decision method is improved by about 1 to 1.5dB compared with the multi-round turbo enhancement method using the original hard decision method.

Claims (1)

1. a partial judgment method in the MIMO wireless communication receiver interference elimination technology, is characterized in that, comprises the following steps: (1) Set the threshold, make partial judgments on the judgment statistics, and obtain partial judgment signals; the specific process is: Set the threshold ε, and the value range of the threshold is 0<ε<1; let the decision statistic be expressed as r, make a partial decision on the decision statistic r, and obtain a part of the decision signal

In the partial judgment process, it is necessary to make partial judgments on the in-phase component and the quadrature component of the decision statistic r, and the process of making partial judgment on the in-phase component of the decision statistic r is as follows: Let the k-th decision threshold of the in-phase component of the decision statistic r be D _k ,k=1,...,K,K is the total number of decision thresholds, if the in-phase component of the decision statistic r falls within the (D _k -ε,D _k +ε) region, no decision is made and the original value is kept; If the in-phase component of the decision statistic falls outside the (D _k -ε, D _k +ε) area, then according to the principle of the closest Euclidean distance, the judgment is the coordinate value corresponding to the in-phase component of the corresponding constellation point, and the orthogonality of the decision statistic r The partial judgment process of the component is the same as the partial judgment process of the in-phase component; after completing the judgment of the above-mentioned in-phase component and quadrature component, the partial judgment signal is obtained

(2) Perform signal reconstruction on part of the decision signals obtained in step (1), and use the reconstructed signals to eliminate interference; among them, the process of signal reconstruction for part of the decision signals is to use part of the decision signals to adopt the original hard decision reconstruction method Carry out signal reconstruction; the process of reconstructing the signal for interference elimination is to use the signal reconstructed by part of the judgment signal to perform interference elimination by using the original hard judgment interference elimination method.

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