Performance of Selection Combining Diversity in $\eta{-}\mu$ Fading Channels With Integer Values of $\mu$

An analytical study of selection combining (SC) diversity under $\eta{-}\mu$ multipath fading is presented, considering that the $\mu$ parameter takes integer values. Closed-form expressions are derived for the statistics of the signal-to-noise ratio (SNR) at the combiner output and for the error rate of some relevant $M$-ary modulation schemes. Additionally, closed-form expressions are also derived for the channel capacity, considering different adaptive transmission policies. It is shown that, if the number of receive branches is high enough, severe fading may result in an increased channel capacity for all the considered transmission strategies due to the branch selection and the higher channel variability. This is in sharp contrast to the behavior of capacity in single-channel reception schemes. Monte Carlo simulations have been carried out to validate the derived analytical expressions.