Independent Rayleigh, Ricean, and Nakagami sum distribution and density approximations for wireless applications

The statistical sum distributions of independent Rayleigh, Ricean, and Nakagami random variables occur extensively in the modeling and performance analysis of wireless communication systems. Closed-form expressions do not exist for most of these sum distributions and consequently, they are often approximated or calculated numerically. In this thesis, accurate closed-form approximations for the Rayleigh, Ricean, and Nakagami sum distributions and densities are derived. These approximations are demonstrated to be valid for a wide range of probability values, statistical parameters, and number of summands. The proposed approximations facilitate efficient performance analysis for a broad range of applications. One particular application considered in this thesis is equal gain combining diversity systems. Accurate closed-form expressions for the average error and outage probabilities of these systems are derived.