zhouqitu.m

功率普估计

clear

f = 2000; 
fs = 100000;
N = 256;

t = 0:(N-1);
x = sin(2*pi*f/fs*t);
y = awgn(x,10);

figure,plot(x);
figure,plot(y);


y = fft(y,N);
y = abs(y).^2/N;
f1 = (0:fs/N:(N-1)*fs/N) - fs/2;
%figure,plot(f1,fftshift(y));
%%figure,plot(f1,y);
title('周期图法');

figure,plot(f1,10*log10(fftshift(y)));

%axis([-50000 50000 -4 70]);