Circular convoluti
When a function gT is periodic, with period T, then for functions, ƒ, such that ƒ∗gT exists, the convolution is also periodic and identical to:
where to is an arbitrary choice. The summation is called a periodic summation of the function ƒ.
If gT is a periodic summation of another function, g, then ƒ∗gT is known as a circular, cyclic, or periodic convolution of ƒ and g.