Novel approximations to the statistics of general cascaded Nakagami-m channels and their applications in performance analysis

A novel closed-form approximation is derived for the statistics of cascaded Nakagami-m channels with integer and half-integer m. The adopted approximation generalizes the prior results by incorporating cross-correlations between each pair of component channels. The approximative probability density function is constructed by an easily computable log-normal density and its associated orthogonal polynomials. The proposed approximation shows good agreement with numerical simulations under light fading condition and yields improved accuracy compared with the well-known lognormal distribution. To illustrate the usefulness of the derived result, we apply it in performance analysis involving the cascaded Nakagami-m channels.