circular convolution without cconv

I have 2 vecrors of periodic coeffecients a_k , b_k. both of them size 2001 , start from 1 to 2001. I need to make circular convolution between them without using cconv.

The formula: f_k = (l=(-1000,1000))a_l*b_k-l

N=2001; l is vector (-1000:1:1000);

I don't know how to write this in Matlab without using cconv func..(also better without for loops).

I realy appreciate the help!

[David Goodmanson]

HI Liron,

One can do circular convolution by means of the fft, and there is plenty of information on the web about that.