showsin.m

some simulation on digital FM,as well as some dsp implemention

function [ output_args ] = showsin( input_args )
%UNTITLED1 Summary of this function goes here
%   Detailed explanation goes here


N=1024;
f1=1000;
fp=19000;
fp2=38000;
fs=152000;
fx=-0.5:1/N:0.5-1/N;
w=2*pi*f1/fs;
wp=2*pi*fp/fs;
wp2=2*pi*fp2/fs

% 原始信号
L=sin(w*[0:N-1]);
M=L;
ps=sin(wp*[0:N-1]);
ps2=sin(wp2*[0:N-1]);

% 调制信号
S=L.*ps2+M;

% 时域波形
subplot(2,1,1);
plot(S);
title('没有导频');
subplot(2,1,2);
plot(S+0.1*ps)
title('添加导频');
% plot(fftshift(abs(fft(S))));