mohuhanshugujishipin.m

用模糊函数法进行时频分析

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%%%%% 用模糊函数估计频差、时差仿真算法
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clear all;clc;
 f0=1000;%载频
 fm=20;%调制信号频率
 fd=20;%多普勒频骗
 td=50;%时移
 fs=f0*2;%采样速率
 kf=75/fm;
 N=fs;%样点数
  t=(0:1/fs:(N-1)/fs);%采样点时间序列
  x=cos(2*pi*f0*t+kf*sin(2*pi*fm));
  y=cos(2*pi*(f0+fd)*t+kf*sin(2*pi*fm));
  
% x=cos(2*pi*f0*t+5*sin(2*pi*fm*t)); %直达波信号
  % figure(1);subplot(411);plot(x);ylabel('直达波');
 %y=cos(2*pi*(f0+fd)*t+kf*sin(2*pi*fm*t));%回波信号
 y= circshift(y,[0 td]) ;
 x=x';y=y';
   % subplot(412);plot(y);ylabel('回波');
   
% AMBIFUNB([x,y]) ;
  [NAF,TAU,XI]=AMBIFUNB([x,y]);
%  mesh(TAU,XI,abs(NAF));
 plot(XI,abs(NAF)) ;
%[TFR,T,F]=tfrwv([x,y]);
 %[TFR,T,F]=tfrwv([x,y]);
% y=XX(200,[1:400]);
% plot3(abs(NAF),TAU,XI);
%contour3(TFR);
grid on
axis square