Higher order statistics of cooperative mobile-to-mobile relay communications over composite fading channels

The paper investigates mobile-to-mobile (M2M) dual-hop amplify-and-forward relay (AFR) communications in composite fading environments. We model composite fading signal as the product of Nakagami-m (Nm) and Gamma (G) random processes (RPs) in order to address multipath-shadowing scenario and derive novel, fast computing, closed form mathematical formulas for: 1) probability density function; 2) cumulative distribution function; 3) outage probability; 4) average level crossing rate; 5) average fade duration. The integral form statistical expressions are directly approximated by Laplace approximation (LA) method and exponential LA method. Moreover, we extended the model to cooperative M2M relay communications with n parallel independent dual-hop AFR links with selection combining scheme (SCS) at reception. The obtained results are numerically presented in order to show the impact of multipath-shadowing severity sets of parameters on the proposed M2M system. The detailed comparison of exact and approximated numerical results is provided for all considered statistical measures.