runqfskber.m

nc mfsk调制

clear all;
close all;
format long;
snr=0:10;
for n=1:length(snr);
    peAnaly(n)=(4-1)/2*exp(-10^(snr(n)/10));
    i=1;
    number=0;
     aa=snr(n)
    for i=1:20;
    
%%% random symbols
           BS=randint(200,1,2);

%%% FSK modulator
             fsk=fskmod(BS, 4,2,4,20);

%%% received signals with additive white Gaussian noise
         
         Rxsignals=awgn(fsk, aa, 'measured');

%%% demodulated signals
         fskdem=fskdemod(Rxsignals, 4,2,4,20);

%%% count number of errors
         [num1, ratio]=biterr(BS, fskdem);
        number=number+num1;
   end
    pe(n)=number/20000;
end
figure; plot(snr,pe,'-ro',snr,peAnaly,'-b*');
h=legend('Simulated Pe', 'Analytical Pe');
title('Pe of QFSK with Additive White Gaussian Noise');
axis([0 10 1.0e-006 1]);
set(gca, 'YScale', 'log');
xlabel('Eb/No (dB)');
ylabel('probability of err Pe');
grid on;