MATLAB coding for MIMO systems

[kalaimathi]

hi all
could anyone please tell me where can i get matlab coding for ML detection for 4x4 MIMO using MMSE I HAVE TO COMPARE THE ML PERFORMANCE USING MMSE WITH ZF AND MRC THAT IS PLOTTING BER VS SNR FOR 4X4 MIMO :|
please help

 

[pashasrp67]

This is the code for 2*2 MIMO system, which employs BPSK Modulation.


Eb_N0_dB= 0:32; % multiple Eb/N0 values
nTx = 2;
nRx = 2;
M=input('Enter the M Value for M-Ary: \n');
% Transmitter
[c t]=Rayleigh_Calculation(M);
figure,plot(t,c);
ip= rand(1,N)>0.5; % generating 0,1 with equal probability
tt=N/M;
s = 2*ip-1;
for ii = 1:length(Eb_N0_dB)

sMod = kron(s,ones(nRx,1)); %
sMod = reshape(sMod,[nRx,nTx,M/nTx]); % grouping in [nRx,nTx,N/NTx ] matrix

h = 1/sqrt(2)*[randn(nRx,nTx,M/nTx) + j*randn(nRx,nTx,M/nTx)]; % Rayleigh channel
n = 1/sqrt(2)*[randn(nRx,M/nTx) + j*randn(nRx,M/nTx)]; % white gaussian noise, 0dB variance
y = squeeze(sum(h.*sMod,2)) + 10^(-Eb_N0_dB(ii)/20)*n;

% Receiver
inv(H^H*H+sigma^2*I)*H^H
hCof = zeros(2,2,M/nTx) ;
hCof(1,1, = sum(h,2,.*conj(h,2,),1) + 10^(-Eb_N0_dB(ii)/10); hCof(2,2, = sum(h,1,.*conj(h,1,),1) + 10^(-Eb_N0_dB(ii)/10); hCof(2,1, = -sum(h,2,.*conj(h,1,),1); % c term
hCof(1,2, = -sum(h,1,.*conj(h,2,),1); % b term
hDen = ((hCof(1,1,.*hCof(2,2,) - (hCof(1,2,.*hCof(2,1,)); % ad-bc term
hDen = reshape(kron(reshape(hDen,1,M/nTx),ones(2,2)),2,2,M/nTx); % formatting for division
hInv = hCof./hDen; % inv(H^H*H)

hMod = reshape(conj(h),nRx,M); % H^H operation

yMod = kron(y,ones(1,2)); % formatting the received symbol for equalization
yMod = sum(hMod.*yMod,1); % H^H * y
yMod = kron(reshape(yMod,2,M/nTx),ones(1,2)); % formatting
yHat = sum(reshape(hInv,2,M).*yMod,1); % inv(H^H*H)*H^H*y
ipHat = real(yHat)>0;
nErr(ii) = size(find([ip- ipHat]),2);

end
end

 

[kalaimathi]

@pashasrp67 thanks for you help and could you please tell me where can i get the matlab coding for 4x4 mimo using mmse and the modulation is QAM

 

[dhekoura]

This code is for 4QAM modulation , it help you to understand this modulation and use this function to complete your code:
function s=modulation_4_qam(m,n)
%modulation 4 qam
i=sqrt(-1);
for I=0:n-1,
if m(2*I+1)==1 & m(2*I+2)==1 s(I+1)=-1-i;
elseif m(2*I+1)==1 & m(2*I+2)==-1 s(I+1)=-1+i;
elseif m(2*I+1)==-1 & m(2*I+2)==1 s(I+1)=1-i;
else s(I+1)=1+i;
end
end