Wireless secrecy under multivariate correlated Nakagami-m fading

Current wireless secrecy research in the literature has mainly been performed for one wiretapper under correlated fading. In this paper, a new wireless secrecy framework for multiple wiretappers under multivariate exponentially-correlated (exp.c.) Nakagami-m fading is proposed. Using the distribution of multivariate exp.c. Nakagami-m fading, new, exact, and compact expressions for the ergodic secrecy capacity, and secrecy outage probability (SOP) under multiple wiretappers are obtained for an integer fading parameter m. A secrecy analysis is also performed for the first time in this paper using an adaptive on/off transmission encoder under multivariate exp.c. Nakagami-m fading. A secrecy analysis with three wiretappers under quadrivariate exp.c. Nakagami-m fading is also given, which shows the effectiveness of the new framework. Simulation results are shown to exactly match theoretical predictions

New generalised approximation methods for the cumulative distribution function of arbitrary multivariate Rayleigh random variables

Based on our previous works, we revise a simple series expansion for multivariate probability density functions (PDF) of the Rayleigh distribution. From there we derive a similar expression for the cumulative density function (CDF) of multivariate Rayleigh random variables of arbitrary dimension and covariance matrix. The CDF is of particular interest as it can be used to compute outage probabilities of multi-channel wireless systems, for which we provide an example. We compare the performance of the newly proposed approximation to recently proposed methods based on numerical integration methods