Sum of Squared Fluctuating Two-Ray Random Variables With Wireless Applications

The fluctuating two-ray (FTR) channel fading offers good fit for small-scale experimental data in millimeter wave communications. We first investigate the statistical characterizations of the sum of independent nonidentically distributed squared FTR random variables. More specifically, the exact and approximate analytical expressions for moment generating function, probability density function, and cumulative distribution function are derived. Then, the performance of the maximal-ratio combining system over FTR fading channels is assessed in terms of the outage probability (OP) and the average bit error probability (ABEP). Moreover, asymptotic OP and ABEP expressions are obtained to obtain physical insights into the impact of the system and channel parameters on the overall performance. Finally, the correctness of our results is verified by simulation results.