k-fold Convolution of probability density

Dear All,

I am new in MATLAB. I do not have much idea on programming. I have data for probability density function, f(x). Where 'x' is in logarithmic scale. I want to do k-fold convolution of 'f(x)', where 'k' is from "0 to infinity". Then I need to plot k-fold convoluted f(x) w.r.t "x' .

In MATLAB, there are two kinds of convolution option...1. Circular and 2. Linear Convolution. I am not getting which will be suitable for me and how to proceed.

Kindly give some idea on this.

Thanking you in advance.