sep_8_4_rayleigh.m

用MATLAB对QAM进行仿真计算（32QAM）

% function pf=(r,snr_db) Average SEP for 8*4 QAM in slow Rayleigh fading
% for different ratios r=dq/di
clear all;close all;clc;
MI=8;
MQ=4;
M1=1-1/MI;
M2=1-1/MQ;
% σ^2=1/2;σn^2=1;ai=di/σn;aq=dq/σn;r=dq/di;
% r=1;
r=[1,sqrt(21/5),21/5];
SNR_dB=10:1:40;
SNR=10.^(SNR_dB./10);
AI1=sqrt(SNR.*2./(21+5*r(1).^2));
AQ1=r(1).*AI1;
AI2=sqrt(SNR.*2./(21+5*r(2).^2));
AQ2=r(2).*AI2;
AI3=sqrt(SNR.*2./(21+5*r(3).^2));
AQ3=r(3).*AI3;
    %r=1
Pf_1=M1.*(1-f(AI1))+M2.*(1-f(AQ1))-M1.*M2.*(1-2./pi.*(f(AI1).*atan(1./r(1)./f(AI1))+f(AQ1).*atan(r(1)./f(AQ1))));
    %r=sqrt(21/5)
Pf_2=M1.*(1-f(AI2))+M2.*(1-f(AQ2))-M1.*M2.*(1-2./pi.*(f(AI2).*atan(1./r(2)./f(AI2))+f(AQ2).*atan(r(2)./f(AQ2))));
    %r=21/5
Pf_3=M1.*(1-f(AI3))+M2.*(1-f(AQ3))-M1.*M2.*(1-2./pi.*(f(AI3).*atan(1./r(3)./f(AI3))+f(AQ3).*atan(r(3)./f(AQ3))));
semilogy(SNR_dB,Pf_1,'-');
hold on;
semilogy(SNR_dB,Pf_2,'--');
semilogy(SNR_dB,Pf_3,'.');
legend('r=1','r=(21/5)^{1/2}','r=21/5');
axis([10,40,1e-3,1]);
xlabel('10log_{10}(E_{T}/\sigma_{n}^2)');
ylabel('SEP');
grid on;