1. The problem statement, all variables and given/known data I need to find the pdf of sum of "n" iid non central chi-square distributed RV's. 2. Relevant equations The PDF of the non-central chi-square RV is given herehttps://en.wikipedia.org/wiki/Noncentral_chi-squared_distribution 3. The attempt at a solution i tried to find the product of the characteristics function of "n" RV, but how to continue?