On the performance analysis of cooperative non-regenerative relay systems over generalized fading channels

In this article, we present three novel moment generating function (MGF) based approaches for performance evaluation of multi-hop, multi-relay cooperative amplify-and-forward (CAF) networks over a myriad of stochastic channel models. Method I is based on a recursive expansion of the MGF of effective SNR for a 2-hop CAF relay network developed in [15]. The second method is also similar to Method I except that it requires the exact MGF of the end-to-end SNR for a 2-hop relay network. Method III involves the split of a multi-hop route path into two sections, evaluating the MGF of the “weakest link” in each section, and then finding the MGF of end-to-end SNR using the result in [15] for a 2-hop CAF network. We show that all the above mentioned methods closely approximate the `exact´ MGF and yield performance comparable to existing bounds. Unlike the existing methods (which are restrictive to specific fading channels), our proposed solutions is quite general and can be applied to a wide range of fading environments while dramatically reducing the computational complexity of average symbol error rate (ASER) for multi-hop multi-branch CAF relay networks. Moreover, our final solutions for the MGF of end-to-end SNR are expressed in closed-form for first two methods, and in terms of a single integral for Method III. The accuracies of our approximations have been validated with “exact” formulas that are available for specific wireless fading environments and via Monte Carlo computer simulations.