Performance analysis of relay-assisted mobile-to-mobile communication in double or cascaded Rayleigh fading

We consider a mobile-to-mobile (M2M) communication scenario in a crowded city or suburban area, where each mobile terminal is surrounded by a group of scatterers. The non-line of sight (NLOS) communication channel is modelled as non-frequency selective double or cascaded Rayleigh distributed. Cooperative relaying with amplify and forward (AF) protocol is used to improve the overall system performance. System performance is investigated in two sets. In the first case, the source (S) to destination (D) direct link is double Rayleigh distributed. The relay (R) or access point is assumed to be located above rooftop level and the cooperative links are flat Rayleigh faded. In the second case, both the direct and cooperative links are considered double Rayleigh faded. Modelling and simulations are used to evaluate overall performance in conditions, when the cooperative link is uncorrelated, partially correlated and completely correlated with the direct link.