Modelling and simulation of Rayleigh fading, path loss, and shadowing fading for wireless mobile networks

In this paper, we first derive two explicit mathematical expressions of bit error rates (BERs) with Rayleigh fading for differential phase shift keying (DPSK) and quadrature amplitude modulation (QAM), and establish corresponding simulation models to realize the effect of Rayleigh fading. Next, we propose a mathematical expression to define the effect of shadowing fading and an approach to computing it. Then, we optimize the effect of path loss through adapting the value of the path loss exponent to different environments. Finally, using a packet-oriented simulation tool, OPtimized Network Engineering Tool (OPNET), we realize the effects of Rayleigh fading and shadowing fading, optimize the effect of path loss, and investigate the integrated impact of these effects on the performance of wireless mobile networks including wireless local area networks (WLANs) and mobile ad hoc networks (MANETs). Simulation results not only coincide with the experimental results in present literature, but also show that these effects exert a non-negligible impact on the performance of wireless mobile networks. Accordingly, our new models and approaches make the present over-optimistic simulation results more accurate and reasonable.