Average BER of multihop communication systems over fading channels

Multihop transmission is a way to attain broader coverage by splitting the communication link from the source to the destination into several, possibly shorter links/hops. This paper presents an expression for the moment generating function (MGF) of the end-to-end signal-to-noise ratio of multihop non-regenerative systems, which makes it possible to use the MGF-based approach for calculating the average BER of several modulation schemes. Due to the complexity of the expression introduced, the paper presents also a lower bound on the average bit error rate performance of the systems under study. Numerical results show that relaying enhances the system performance compared with equivalent direct transmission. They also show that increasing the number of hops has a diminishing effect on the degradation of the performance of multihop systems.