Doubt with my codings..Pls help me correct it

clc;
clear all;
close all;
%input
M=1024;
nt=2;
nr=1;
L=65;
%Generate random data
m=4;
msg1=randint(M/2,1,m);
figure(1)
stem(msg1)
grid on
xlabel('data points')
ylabel('transmitted data phase representation')
title('Transmitted Data "O"')
msg2=randint(M/2,1,m);
figure(2)
stem(msg2)
grid on
xlabel('data points')
ylabel('transmitted data phase representation')
title('Transmitted Data "O"')
% QPSK modulation
qpsk_modulated_data1=pskmod(msg1,m);
qpsk_modulated_data2=pskmod(msg2,m);
%scatterplot(qpsk_modulated_data1);
%title('qpsk modulated transmitted data1');
%scatterplot(qpsk_modulated_data2);
%title('qpsk modulated transmitted data2');
%IFFT
x1=ifft(qpsk_modulated_data1);
x2=ifft(qpsk_modulated_data2);
%scatterplot(x1)
%scatterplot(x2)
x=vertcat(x1,x2);
%Add CP
message = randint(1,M,4); %Assuming QPSK symbols
length_cyclic = 15;
starting =M - length_cyclic + 1;
cyclic_prefix = message(starting : end);
prefixed = horzcat(cyclic_prefix,message);
%channel
h1=gallery('circul',M:M);
h2=gallery('circul',M:M);
e=horzcat(h1,h2);
f=vertcat(h1,h2);
h=e*f;
There is no connection of adding CP with my output. How can I make it correct?

7 Comments

@walter: Since I want quick reply,I posted again
What is your "doubt?" Are you receiving an error? Are the results not what you expected? We cannot divine a solution to a problem if we do not know what *is* the problem.
My adding of CP does not connects with the rest of the program. I am not sure whether it is right or not
@Jan : yes,I deleted
@melody: I don't like this. The voluntary contributors answer as fast they can, when they know an answer. Double posting is not an option to push the readers, because they waste time during reading the question again, which they could not answer the first time. If you do not get a fast answer, this is usually caused by an incomplete question.
Please delete the double post.
Btw. Please use meaningful tags. *All* questions in this forum concern "matlab" and "matlab code". Therefore I have deleted these tags.
What does "connects with the rest of the program" mean?
@Jan: I am a beginner and I have a doubt whether adding CP has an effect on h ( channel response)

Sign in to comment.

Answers (1)

Your calculation of "h" does not involve any variables defined after your very early "%input" section. Therefore, adding CP has no effect on "h", at least not in the code you have written.

Asked:

on 6 Mar 2012

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!