Accurate approximations for the symbol error probability of cooperative non-regenerative relay systems over generalized fading channels

In this article, we present a unified approach for the asymptotic analysis of symbol error rates for two-hops cooperative non-regenerative multi-relay networks over a myriad of stochastic channel models. The analysis can be also extended to other types of cooperative strategies and multi-hop networks without much difficulty. The proposed moment generating function (MGF) framework is also sufficiently general to encapsulate all types of coherent and non-coherent digital modulation schemes. In addition to simplifying the computation complexity of average symbol error rate (ASER) for cooperative amplify-and-forward (CAF) diversity schemes treated in the literature, we also provide accurate ASER approximations for many fading environments that heretofore had resisted a simple solution. The accuracy of our approximations has been validated with closed-form formulas that are available for specific fading environments (e.g., Rayleigh and Nakagami-m channels) and via computer (Monte Carlo) simulations.