SM_4QAM_ML

4 QAM Spatial modulation with maximum likehood detection

clc
clear all;
N=3*10^5;                      %number of symbol
symbol_set=[1+1i;1-1i;1i-1;1i-1i]/sqrt（2）;   %set of symbol to be transmitted
symbolset_size=4;
symbol_size=N/3;
Eb_No_Db=（0:25）;
nTx=2;                              % number of transmitting antenna
nRx=2;                              % number of receiving antenna
antennabits=[0;1];
Sym_to_bit=[0 0;0 1;1 0;1 1];

i=randi（[0 1]1N） ;    % generating stream of bits

x=vec2mat（i3）;          % grouping generated bits into 3

s=kron（symbol_setones（nRx1））;   % grouping symbols into matrix
s=repmat（s[1 nTx]）;
xTransmit=zeros（symbol_sizenTx）;                                                             
xDemod=zeros（symbol_size3）;                                                                  

antenna_symbol=zeros（N/31）;    
antenna_symbol（:1）=x（:1）+1;       % 
antenna_symbol（:2）=symbol_set（bi2de（x（:2:3）‘left-msb‘）+1） ;   %Modulate

for ii=1:length（Eb_No_Db）
    
    for jj=1:symbol_size
       
        h=1/sqrt（2）*（randn（nRxnTx））+ 1i*（randn（nRxnTx））;    % rayleigh channel
        
        n=1/sqrt（2）*（randn（nRx1））+1i*（randn（nRx1））;            % noise
        
    H=kron（ones（symbolset_size1）h）;      
      sD= H.*s;
      
            xTransmit（jjantenna_symbol（jj1）） =antenna_symbol（jj2） ;             % Assign Symbol and Antenna Index
            xTransmit2=kron（xTransmit（jj:）ones（nRx1））;
            
            y = sum（xTransmit2.*h2） +10^（-Eb_No_Db（ii）/20）*n;
            
            y2=kron（ones（symbolset_size1）y）;                                                  % Copy for Symbol set
            y2=repmat（y21nRx）;                                                            % Copy for Antenna
            y2=abs（y2-sD）;

            z=zeros（symbolset_sizenTx）;
            z（1:）=abs（sum（y2（1:2:）1））;
            z（2:）=abs（sum（y2（3:4:）1））;
            z（3:）=abs（sum（y2（5:6:）1））;
            z（4:）=abs（sum（y2（7:8:）1））;
            [v r]=min（z）;
            [v c]=min（v）;
            xDemod（jj1）=antennabits（c）;
            
            xDemod（jj2:3）=Sym_to_bit（r（c）:）;
      
    end
    
    nErr（ii）= size（find（i-reshape（xDemod‘1[]））2）;
end
simBER = nErr/N;


close all
figure
semilogy（Eb_No_DbsimBER‘m.-‘‘linewidth‘2）;
axis（[0 20 10^-5 1]）
grid on
legend（‘Sim 4QAM‘）;
xlabel（‘Eb/No dB‘）
ylabel（‘Bit Error Rate‘）
title（‘Bit Error Prob 4QAM 2x2 （3 Bit） with SM in Rayleigh Fading‘）

 属性            大小     日期    时间   名称
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     文件       2498  2014-05-17 01:18  SM_4QAM_ML.m

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                 2498                    1