【 MATLAB 】两个序列的卷积和运算的MATLAB实现（1）

设矩形脉冲  是脉冲响应  的LTI系统的输入，求输出 y(n).

下面的脚本中用到了一个自定义的函数，也就是两个信号相加的函数：

相关博文：【 MATLAB 】基本序列运算及其MATLAB的等效表示

  

   

    

     

    
    

     

      function [y,n] = sigadd(x1,n1,x2,n2)
     
    
   

    

     

    
    

     

      % implements y(n) = x1(n) + x2(n)
     
    
   

    

     

    
    

     

      % [y,n] = sigadd(x1,n1,x2,n2)
     
    
   

    

     

    
    

     

      %——————————————————————————————
     
    
   

    

     

    
    

     

      % y = sum sequence over n, which includes n1 and n2
     
    
   

    

     

    
    

     

      % x1 = first sequence over n1
     
    
   

    

     

    
    

     

      % x2 = second sequence over n2( n2 can be different from n1)
     
    
   

    

     

    
    

     

      %
     
    
   

    

     

    
    

     

      n = min( min(n1), min(n2) ):max( max(n1), max(n2) ); %duration of y(n)
     
    
   

    

     

    
    

     

      y1 = zeros(1,length(n)); y2 = y1; %initialization
     
    
   

    

     

    
    

     

      y1( find( ( n >= min(n1) )&( n <= max(n1) ) == 1  )  ) = x1; %x1 with duration of y1
     
    
   

    

     

    
    

     

      y2( find( ( n >= min(n2) )&( n <= max(n2) ) == 1  )  ) = x1; %x2 with duration of y2
     
    
   

    

     

    
    

     

      y = y1 + y2;
     
    
  
 

直接给出MATLAB脚本：

  

   

    

     

    
    

     

      clc
     
    
   

    

     

    
    

     

      clear
     
    
   

    

     

    
    

     

      close all
     
    
   

    

     

    
    

     
 
     
    
   

    

     

    
    

     

      % help stepseq
     
    
   

    

     

    
    

     

      %   generate x(n) = u(n - n0); n1 <= n <= n2
     
    
   

    

     

    
    

     

      %  _____________________________________________
     
    
   

    

     

    
    

     

      %  [x,n] = stepseq(n0, n1, n2);
     
    
   

    

     

    
    

     

      [u1,n1] = stepseq(0,-5,45);
     
    
   

    

     

    
    

     

      [u2,n2] = stepseq(10,-5,45);
     
    
   

    

     

    
    

     
 
     
    
   

    

     

    
    

     

      % generate signal x(n)
     
    
   

    

     

    
    

     

      [x,n] = sigadd(u1,n1,-u2,n2);
     
    
   

    

     

    
    

     
 
     
    
   

    

     

    
    

     

      % generate signal h(n)
     
    
   

    

     

    
    

     

      m = -5:45;
     
    
   

    

     

    
    

     

      h = ( (0.9).^m ).* u1;
     
    
   

    

     

    
    

     
 
     
    
   

    

     

    
    

     
 
     
    
   

    

     

    
    

     

      % the convolution of x(h) and h(n)
     
    
   

    

     

    
    

     

      y = conv(x,h);
     
    
   

    

     

    
    

     

      % ensure the index
     
    
   

    

     

    
    

     

      nyb = n(1)+ m(1);
     
    
   

    

     

    
    

     

      nye = n(length(x)) +n(length(h));
     
    
   

    

     

    
    

     

      ny = nyb:nye;
     
    
   

    

     

    
    

     
 
     
    
   

    

     

    
    

     
 
     
    
   

    

     

    
    

     

      subplot(3,1,1);
     
    
   

    

     

    
    

     

      stem(n,x);
     
    
   

    

     

    
    

     

      title('x(n)');
     
    
   

    

     

    
    

     

      xlabel('n')
     
    
   

    

     

    
    

     
 
     
    
   

    

     

    
    

     

      subplot(3,1,2);
     
    
   

    

     

    
    

     

      stem(m,h);
     
    
   

    

     

    
    

     

      title('h(n)');
     
    
   

    

     

    
    

     

      xlabel('n')
     
    
   

    

     

    
    

     
 
     
    
   

    

     

    
    

     

      subplot(3,1,3);
     
    
   

    

     

    
    

     

      stem(ny,y);
     
    
   

    

     

    
    

     

      title('the conv of x(n) and h(n)');
     
    
   

    

     

    
    

     

      xlabel('n')
     
    
   

    

     

    
    

     

      xlim([-5,45]);
     
    
  
 

文章来源: reborn.blog.csdn.net，作者：李锐博恩，版权归原作者所有，如需转载，请联系作者。

原文链接：reborn.blog.csdn.net/article/details/83280406