FSK mod and demod with fading and noise

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Salma 2011-4-28

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此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/6422-fsk-mod-and-demod-with-fading-and-noise

I'm trying to design FSK modulator and demodulator with noise and flat fading but the graph of snr vs ber with fading in wrong, any idea how to fix it??

clear all;clf;clc;close all;
M = 2; 
k = log2(M);
EbNo = 5;
Fs = 16; 
nsamp = 17; 
freqsep = 8;
n=10000;
msg = randint(n,1,M); 
txsig = fskmod(msg,M,freqsep,nsamp,Fs); 
ab=abs(txsig);
ps=(sum(ab.^2))/n;
for snr=1:30
    pn=10.^(-0.1.*snr).*ps;
    noise= sqrt(pn)*randn(1,n*nsamp); 
G1=randn(1,n); %generating fading coefficients
G2=randn(1,n);
v= sqrt(power(G1,2)+ power(G2,2));
A=v(2);
theta=2*pi*rand;
alph=A*exp(j*theta);
msg_rx  = alph*txsig + noise'; % txsig is 1700x1 and noise is 1x1700, so need transpose
msg_rxx=msg_rx.*(1/A)*conj(alph);
msg_rrx = fskdemod(msg_rxx,M,freqsep,nsamp,Fs);  
[num,BER] = biterr(msg,msg_rrx); % Bit error rate
w(snr)=BER;
end
d=[1:30];
figure
semilogy(d,w)