pls help me write BER codings
2 ビュー (過去 30 日間)
古いコメントを表示
Pls help me write codings for BER. I have tried many,but get wrong. Wanted to plot BER vs SNR.
clc;
clear all;
close all;
%input
M=1024;
nt=2;
nr=1;
L=65;
%Generate random data
m=4;
msg1=randint(M,1,m);
msg2=randint(M,1,m);
msg=vertcat(msg1,msg2);
% QPSK modulation
qpsk_modulated_data1=pskmod(msg1,m);
qpsk_modulated_data2=pskmod(msg2,m);
%IFFT
x1=ifft(qpsk_modulated_data1);
x2=ifft(qpsk_modulated_data2);
x=vertcat(x1,x2);
%channel
temp=randint(1,L-1);
temp=[temp zeros(1,960)];
temp1=transpose(temp);
h1=gallery('circul',temp1);
h1=h1';
temp2=randint(1,L-1);
temp2=[temp2 zeros(1,960)];
temp3=transpose(temp2);
h2=gallery('circul',temp3);
h2=h2';
h=horzcat(h1,h2);
%r
r=h*x;
%--- Joint estimation of channel response and I/Q imbalance
%ek
e=eye(M);
%y due to cfo
y=e*r;
y1=conj(y);
%z due to cfo and i/q
u=(1+exp(-j*10))/2;
u1=conj(u);
v=(1-exp(j*10))/2;
z=(u*y)+(v*y1);
z1=conj(z);
%a
a=(v/u1);
%ur
a1=abs(a)^2;
e1=conj(e);
ur=(e1*(z-(a*z1))/(1-a1));
%p
p=M/nt;
%MIMO channel response
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 = M-(L*nt);
P = zeros(q,M);
P(:,2:2:end) = (p-L)*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*z))/(norm(P*B1*z1))^2;
%channel response
aopt1=abs(aopt)^2;
cha_res=B1*(z-(aopt*z1))/(1-aopt1);
%--------------------------------------------------%
%fft
fft_recdata=fft(r);
%Demodulate the data
qpsk_demodulated_data = pskdemod(fft_recdata,M);
%estimated signal
est_sgl=r*cha_res';
0 件のコメント
採用された回答
Walter Roberson
2012 年 3 月 27 日
There is no obvious place in your code where you use or alter the SNR.
If you were to add noise to your encoded signal before decoding that (noisy) signal, then where would you do that in your code?
4 件のコメント
Walter Roberson
2012 年 3 月 28 日
Your step "pass through channel" is the step at which the noise should logically be added, since the channel is the noisy part.
その他の回答 (0 件)
参考
カテゴリ
Help Center および File Exchange で Link-Level Simulation についてさらに検索
Community Treasure Hunt
Find the treasures in MATLAB Central and discover how the community can help you!
Start Hunting!