OFDM通信系统与QPSK系统性能比较(17)

seldata=rand(1,para*nd*ml)>0.5; % rand : built in function

%****************** Serial to parallel conversion ***********************

paradata=reshape(seldata,para,nd*ml); % reshape : built in function

%************************** QPSK modulation *************************

[ich,qch]=qpskmod(paradata,para,nd,ml); kmod=1/sqrt(2); % sqrt : built in function ich1=ich.*kmod; qch1=qch.*kmod;

%******************* IFFT ************************ x=ich1+qch1.*i;

y=ifft(x); % ifft : built in function ich2=real(y); % real : built in function qch2=imag(y); % imag : built in function

%********* Gurad interval insertion ********** [ich3,qch3]= giins(ich2,qch2,fftlen,gilen,nd); fftlen2=fftlen+gilen; N=fftlen2*nd*ml; y=ich3+qch3*i; N=64;

fs=10240000; % Symbol rate df = fs/N; f1 = 0:df:(N-1)*df; y1=ich3+qch3*i; z1 = fft(y1,N); figure;