Estimation of channel response and i/q imbalance of mimo ofdm

Hello all

I am doing a project on joint estimation of i/q imbalance and channel response for mimo ofdm systems.

My output for i/q is 1 and for channel response I get numerous values. I don't know whether it is correct. Share ur ideas.

clc;

clear all;

close all;

%input

M=128;

nt=2;

nr=1;

L=16;

%r

h1=randn(M,1);

h2=randn(M,1);

h=vertcat(h1,h2);

x1=gallery('circul',M:M);

x2=gallery('circul',M:M);

x=horzcat(x1,x2);

r=x*h;

%ek

e=eye(M);

%y due to cfo

y=e*r;

%z due to cfo and i/q

u=(1+exp(-j*10))/2;

v=(1-exp(j*10))/2;

y1=conj(y);

z=(u*y)+(v*y1);

%a

u1=conj(u);

a=(v/u1);

%ur

z1=conj(z);

a1=abs(a)^2;

e1=conj(e);

ur=(e1*(z-(a*z1))/(1-a1));

%p

p=M/nt;

%ud

a1=randn(M,L);

a2=randn(M,L);

A=horzcat(a1,a2);

a11=randn(M,p-L);

a22=randn(M,p-L);

B=horzcat(a1,a11,a2,a22);

B1=inv(B);

ud=B1*ur;

%CRE

q = 96; %p-L
M = 128; 

P = zeros(q,M);

P(:,2:2:end) = (48)*eye(q,M/2);

cre=norm(P*ud)^2;

CRE = norm(P*B1*(z-(a*z1)))^2;

%I/Q_imbalance

o=ctranspose(P*B1*z1); %traspose_conj of p*B1*z1

aopt=(o*(P*B1*z1))/(norm(P*B1*z1))^2;

%channel response

aopt1=abs(aopt)^2;

cha_res=B1*(z-(aopt*z1))/(1-aopt1);

[Janet]

should I change anything?

[Walter Roberson]

Yup. I already told you about inv().

[Janet]

what is mldivide and mrdivide?

If i use mldivide,I get output and also I would like to know why should we not use inv operator

[Janet]

if i write ud=ur\B..I get matrix dimensions mismatch in cre

cre=norm(P*ud)^2;

[Walter Roberson]

http://blogs.mathworks.com/loren/2007/05/16/purpose-of-inv/

[Janet]

@walter: I get error in cre

[Walter Roberson]

Have another look at that blog. It says inv(A)*b should be replaced by A\b . You have the two variables reversed.