On the η - κ Distribution

The recent paper by Yacoub et al. [1] introduces what is referred to as the η – κ distribution to describe the statistical variation of the envelope in a fast fading environment. The paper discusses several properties of the distribution. Two of the properties discussed are the nth moment, E(Pn), and the cumulative probability function (cpf), FPP (•), where P is a random variable representing the normalized envelope. The expression given for E(Pn) (see equation (10) in Yacoub et al. [1]) is a doubly infinite sum of the Gauss hypergeometric function (which, itself, is an infinite sum). That given for FP (•) (see equation (11) in Yacoub et al. [1]) is a triple sum of the incomplete gamma function