MIMO通信系统仿真设计-matlab

%STBC_MIMO_OFDM.m

%这是一个基于空时分组编码的 MIMO_OFDM 通信系统的仿真设计。

%此系统包括 QPSK 调制解调，IFFT 调制，空时编解码，基于训

%练符号的信道估计等通信模块。

clear all

close all

clc

%+++++++++++++++++++++++++++变量++++++++++++++++++++++++++++++

M_psk=4;

bits_per_symbol=log2(M_psk); %位数/符号

%[x1 x2;-x2* x1*] 二天线发送矩阵

% O=[1 2;-2+j 1+j];

%[x1 -x2 -x3;x2* x1* 0;x3* 0 x1*;0 -x3* x2*] 三天线发送矩阵

O=[1 -2 -3;2+j 1+j 0;3+j 0 1+j;0 -3+j 2+j];

co_time=size(O,1);

Nt=size(O,2); %发射天线数目

Nr=2; %接收天线数目

%+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

end

end

co_x=zeros(num_X,1);

for con_ro=1:co_time

for con_co=1:Nt %用于确定矩阵“O”中元素的位置，符号以及共轭情况

if abs(real(O(con_ro,con_co)))~=0

delta(con_ro,abs(real(O(con_ro,con_co))))=sign(real(O(con_ro,con_co)));

epsilon(con_ro,abs(real(O(con_ro,con_co))))=con_co;

eta(abs(real(O(con_ro,con_co))),co_x(abs(real(O(con_ro,con_co))),1))=con_ro;

eta=eta.';

eta=sort(eta);

% 坐标： (1 to 100) + 14=(15:114)

carriers = (1: carrier_count) + (floor(IFFT_bin_length/4) - floor(carrier_count/2));

conjugate_carriers=IFFT_bin_length-carriers+2;

tx_training_symbols=training_symbol(Nt,carrier_count);

snr_min=3; %最小信噪比

snr_max=15; %最大信噪比

graph_inf_bit=zeros(snr_max-snr_min+1,2,Nr); %绘图信息存储矩阵

graph_inf_sym=zeros(snr_max-snr_min+1,2,Nr);

for SNR=snr_min:snr_max

clc

disp('Wait until SNR=');disp(snr_max);

SNR

n_err_sym=zeros(1,Nr);

baseband_out=round(rand(baseband_out_length,bits_per_symbol));

de_data=bi2de(baseband_out);

data_buf=pskmod(de_data,M_psk,0);

for tt=1:Nt:symbols_per_carrier

data=[];

tx_buf_buf=carrier_matrix(:,tt+ii-1);

for con_r=1:co_time %进行空时编码

for con_c=1:Nt

if abs(real(O(con_r,con_c)))~=0

XX((con_r-

1)*carrier_count+1:abs(real(O(con_r,con_c)))...

*carrier_count,1)*sign(real(O(con_r,con_c)));

else

XX((con_r-

1)*carrier_count+1:abs(real(O(con_r,con_c)))...

*carrier_count,1))*sign(real(O(con_r,con_c)));

end

end

end

end %空时编码结束

XX=[tx_training_symbols;XX]; %添加训练序列

rx_buf=zeros(1,addprefix_length*(co_time+1),Nr);

for rev=1:Nr

time_matrix=[time_matrix((IFFT_bin_length-

cp_length+1):IFFT_bin_length,:);time_matrix];

tx=time_matrix(:)';

%+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

%+++++++++++++++++++++++++++信道++++++++++++++++++++++++++++++

%d=randint(1,4,[1,7]); %4 多经信道模拟

%a=randint(1,4,[2,7])/10;

tx_tmp=tx;

d=[4,5,6,2;4,5,6,2;4,5,6,2;4,5,6,2];