circonvt.m

the file contain many matlab signal source code and many example .

function y=circonvt(x1,x2,N)
% N - point circular convolution between x1 and x2:(time domain)
% ---------------------
% [y]=circonvt(x1,x2,N)
% y=output sequence containing the circular convolution 
% x1=input sequence of length N1<=N
% x2=input sequence of length N2<=N
% N=size of circular buffer
% Method:y(n)=sum(x1(m)*x2((n-m)mod N))
% Check for length of x1
if length(x1)>N
    error('N must be >=the length of x1')
end 
% Check for length x2
if length(x2)>N
    error('N must be >=the length of x2')
end
%
x1=[x1 zeros(1,N-length(x1))];
x2=[x2 zeros(1,N-length(x2))];
m=[0:1:N-1];
x2=x2(mod(-m,N)+1);
H=zeros(N,N);
for n=1:1:N
    H(n,:)=cirshftt(x2,n-1,N);
end
y=x1*H';