p0518.m

用于调制识别的代码

clear
for k=1:100
I=randint(1,1,6);

code=randint(1,165);
fs=100;
fd=1;
fc=4;
[x,m]=pulse(code,fs,fd);
tz=1/fs;
t=tz:tz:165;

figure(1)
subplot(211);
plot(x(1:500));

y=x.*cos(2*pi*4*t);        %ask signal

% y=x.*cos(2*pi*3*t)+(1-x).*cos(2*pi*5*t);     %fsk signal

% x1=1-x.*2;
% y=x1.*sin(2*pi*4*t);        %bpsk signal
     

subplot(212);
plot(y(1:500));

%%%%%%%%%%计算γmax%%%%%%%%%%%%%%%%%%%%%%%%%
Ns=length(y);
y=y(50:100:length(y));
ma=sum(y)./length(y);
an=y./ma;
acn=an-1;
acn=abs(fft(acn));
acn=(acn.^2)./Ns;
gama(k)=max(acn);
end;
figure(2)
plot(gama);