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2x2 MIMO Matlab Code | STBC Matlab Code

By RF Wireless Expert Team

This page covers MIMO MATLAB code for OFDM modulation. The STBC matlab code for 2x1 MIMO and 2x2 MIMO configurations are mentioned.

MIMO STBC 2T1R

Figure 1: STBC 2x1 MIMO configurations

Following is the script for 2x1 MIMO matlab code.

%code:Alamouti code 2x1 MIMO STBC matlab code
clc;
clear all;
close all;
ndata=2;   % number of randam data
x=randint(ndata,1,1); % input data generated
x=[1 2];
%y=[x];
%INPUT DATA BITS
Data_input_bit(1,1)=x(1,1)
Data_input_bit(1,2)=x(1,2)
figure;plot(Data_input_bit);title('input data bits');
%performing 4 qam modulation on the input data
z=qammod(Data_input_bit,4);
%CHANNEL COEFFICENTS MATRIX
h=[0.3 -.2];
%h11=1;  h12=1;
%h21=1;  h22=1;
%NOISE COEFFICENTS
e=[.1 .1];
%e11=1;  e12=1;
%e21=1;  e22=1;
out=zeros(10,1);
for i=1;%:ndata-1;
    % Symbols at time period T;
    out(i,1)=z(i);
    out(i+1,1)=z(i+1);
    % Symbols at time period T+1;
    out(i,2)=-conj(z(i+1));
    out(i+1,2)=conj(z(i));
    %time_t2(i,1)=-conj(z(i+1));
    %time_t2(i+1,1)=conj(z(i));
end
s1=out(i,1);
s2=out(i+1,1);
%for j=1:100
for i=1;
    %Recieved data by RX1 Antenna at time interval T
    r(1,1)= (h(1,1)*s1)               +  (h(1,2)*s2)           + e(1,1);
    %Recieved data by RX1 Antenna at time interval (T+1)
    r(1,2)= ((-h(1,1))*conj(s2))      +  (h(1,2)*conj(s1))     + e(1,2);
end
t(1,1)=((conj(h(1,1))*r(1,1)));
t(1,2)=h(1,2)*(conj(r(1,2)));
t(2,1)=((conj(h(1,2)))*r(1,1));
t(2,2)=((h(1,1)*(conj(r(1,2)))));
%Maximum Likelehhod Detection Scehme
s1_e =t(1,1) + t(1,2);
s2_e= t(2,1) - t(2,2);
%s1_e= ((conj(h(1,1))*r(1,1))) + ((h(1,2)*(conj(r(1,2)))+ );
%s2_e= (((conj(h(2,1)))*r(2,1)) + ((h(1,2)*(conj(r(2,2))));
%performing 4 QAM Demodulation
%final output bits
final_output_Bits(1,1)=qamdemod(s1_e,4)
final_output_Bits(1,2)=qamdemod(s2_e,4)
figure;plot(final_output_Bits);title('final output Bits');

MIMO STBC 2T2R

Figure 2: STBC 2x2 MIMO configurations

Following is the script for 2x2 MIMO matlab code.

%code:Alamouti code 2x2 MIMO STBC matlab code
clc;
clear all;
close all;
ndata=2;   % number of randam data
x=randint(ndata,1,1); % input data generated
x=[2 3];
%y=[x];
%INPUT DATA BITS
Data_input_bit(1,1)=x(1,1)
Data_input_bit(1,2)=x(1,2)
%performing 16 qam modulation on the input data
z=qammod(Data_input_bit,4);
%CHANNEL COEFFICENTS MATRIX
h=[0.3 -.2 ;.1 .11];
%h11=1;  h12=1;
%h21=1;  h22=1;
%NOISE COEFFICENTS
e=[.1 .1;.1 .1];
%e11=1;  e12=1;
%e21=1;  e22=1;
out=zeros(10,1);
for i=1;%:ndata-1;
    % Symbols at time period T;
    out(i,1)=z(i);
    out(i+1,1)=z(i+1);
    % Symbols at time period T+1;
    out(i,2)=-conj(z(i+1));
    out(i+1,2)=conj(z(i));
    %time_t2(i,1)=-conj(z(i+1));
    %time_t2(i+1,1)=conj(z(i));
end
s1=out(i,1);
s2=out(i+1,1);
%for j=1:100
for i=1;
    %Recieved data by RX1 Antenna at time interval T
    r(1,1)= (h(1,1)*s1)               +  (h(1,2)*s2)           + e(1,1);
    %Recieved data by RX1 Antenna at time interval (T+1)
    r(1,2)= ((-h(1,1))*conj(s2))      +  (h(1,2)*conj(s1))     + e(1,2);
    %Recieved data by RX2 Antenna at time interval T
    r(2,1)= (h(2,1)*s1)                +  (h(2,2)*s2)           + e(2,1);
    %Recieved data by RX1 Antenna at time interval (T+1)
    r(2,2)= ((-h(2,1))*conj(s2))       +  (h(2,2)*conj(s1))      + e(2,2);
end
t(1,1)=((conj(h(1,1))*r(1,1)));
t(1,2)=h(1,2)*(conj(r(1,2)));
t(2,1)=((conj(h(2,1)))*r(2,1));
t(2,2)=((h(1,2)*(conj(r(2,2)))));
c(1,1)= ((conj(h(1,2)))*r(1,1));
c(1,2)= h(1,1)*(conj(r(1,2)));
c(2,1)=  ((conj(h(2,2)))*r(2,1));
c(2,2)= ((h(2,1)*(conj(r(2,2)))));
%Maximum Likelehhod Detection Scehme
s1_e =t(1,1) + t(1,2) + t(2,1) + t(2,2);
s2_e= c(1,1) - c(1,2) + c(2,1) - c(2,2);
%s1_e= ((conj(h(1,1))*r(1,1))) + ((h(1,2)*(conj(r(1,2)))+ ((conj(h(2,1)))*r(2,1)) + ((h(1,2)*(conj(r(2,2)))));
%s2_e= ((conj(h(1,2)))*r(1,1)) - ((h(1,1)*(conj(r(1,2))))  + ((conj(h(2,2)))*r(2,1)) - ((h(2,1)*(conj(r(2,2)))));
%performing 16 QAM Demodulation
%final output bits
final_output_Bits(1,1)=qamdemod(s1_e,4)
final_output_Bits(1,2)=qamdemod(s2_e,4)

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