An Accurate Method for Approximating Probability Distributions in Wireless Communications

In performance analyses of wireless communication systems, expressions for the probability distributions of certain random variables are often needed. While exact, efficiently computable closed-form expressions are desirable, they are often very difficult, if at all possible, to obtain. In this paper, the Pearson system of distributions is studied as a means to obtain approximate expressions for such distributions. The usefulness of this approach is illustrated for a number of diversity techniques employed on Nakagami and Weibull fading channels. The resulting relatively simple approximations are shown to be very accurate.