Sum of Non-Identical Independent Squared η-μ Variates and Applications in the Performance Analysis of DS-CDMA Systems

In this paper, new expressions for the probability density function (pdf) of the sum of non-identical independent squared η-μ random variables are derived. Based on our newly derived results, we provide a pdf-based approach for the performance analysis of 1-D and 2-D RAKE receivers in the context of an asynchronous direct sequence code division multiple access system operating over η-μ fading channels. For the considered system, useful performance metrics such as the outage probability, the channel capacity and the average bit error probability are investigated. Extensive numerical and computer simulation results are presented that illustrate the proposed mathematical analysis.