circonv

C = CIRCONV(A,B,N) performs the N-point circular convolution of vectors A and B

Description

CIRCONV N-point circular convolution

C = CIRCONV(A,B,N) performs the N-point circular convolution of vectors A and B. C is returned as a row vector. A and B must be vectors, but may be of different lengths. N must be a positive, non-zero integer. The results of CIRCONV will match that of CONV if N>=( length(A) + length(B) - 1). This is also the alias-free criterion for the circular convolution.

See also CONV

• Acknowledgements: This submission has inspired the following:; Circular Convolution
• MATLAB release: MATLAB 5.3 (R11)

[Andrew Singer]

Why not just multiple the DFT's of the time-aliased signals? It would be MUCH faster...

function xo = talias(x,N)
%% function xo=talias(x,N)
%% time alias data vector x to length N for an N-point DFT.
l=length(x);
nrows=ceil(l/N);
x=[x(:)' zeros(1,N*nrows-l)];
xo = sum( reshape(x,N,nrows)' );

then Y = ifft(fft(talias(a,n)).*fft(talias(b,n)))

[tom tom]

Good job
Wont have to do my homework :)

[Milos Komarcevic]

A very handy function, but I believe the ctranspose ' needs to be changed to transpose .' throughout, otherwise you don't get what you expect when convolving complex vectors.

[prabin gautam]

very needed one

[Anand Rangarajan]

It is handy.

[luis farinha]

Very impoortante for me this script.

[mohd rafi ramli]

that is good

[saurabh jain]

Thanx man

[a singer]

you can do this directly using:
y=ifft(fft(a,n).*fft(b,n),n);
in exactly one line.

[Ory Eger]

Works perfectly! Very useful.

[Pradeep Purohit]

 

[Piyush Tarey]

helped me...in lab..hehe

[desi agarwal]

it says i have to use vectors only

Z = [ 2 -1 0 -3; -3 2 -1 0; 0 -3 2 -1; -1 0 -3 2]
B = [ 1 -3-2*i 4 -3+2*i].' with N =4

it doesnt work?

[Trevor Boyd Smith]

There is a much cleaner more intuitive implementation located at: http://www.mathworks.com/matlabcentral/fileexchange/13030

[chewkaisheng]

how can this related to the 3D sound ??