Closed form and infinite series solutions for the MGF of a dual-diversity selection combiner output in bivariate Nakagami fading

Using a circular contour integral representation for the generalized Marcum-Q function, ( ), we derive a new closed-form formula for the moment generating function (MGF) of the output signal power of a dual-diversity selection combiner (SC) in bivariate (correlated) Nakagamifading with positive integer fading severity index. This result involves only elementary functions and holds for any value of the ratio in ( ). As an aside, we show that previous integral representations for ( ) can be obtained from a contour integral and also derive a new, single finite-range integral representation for ( ). A new infinite series expression for the MGF with arbitrary is also derived. These MGFs can be readily used to unify the evaluation of average error performance of the dual-branch SC for coherent, differentially coherent, and noncoherent communications systems.