Simple and Accurate Approximations for the Sum of Nakagami-m and Related Random Variables.

Simple and accurate closed-form approximations to the probability density function of the sum of independent identically distributed random variables are derived. We propose a unified approach capable of providing the pdf of the sum when the summands involve the generalized Nakagami-m, generalized Gamma, Rayleigh and Weibull random variables. Unlike others work, the approximations do not use any infinite series or require any complicated special functions. Numerical results show that the new approximations have satisfactory accuracies. As an application, the outage probability and the M-QAM average SER performance of pre-detection EGC diversity are presented. [ABSTRACT FROM AUTHOR]