Performance estimation of M-ary PSK in cochannel interference using fast simulation

Fast simulation techniques are applied to estimate accurately the error rates of coherent M-ary phase shift keying in the presence of cochannel interference (CCI) and additive white Gaussian noise in nonfading channels. This type of interference often occurs in mobile wireless systems that employ frequency reuse. In much of the literature, error rates are calculated based on the assumption that CCI can be modelled as Gaussian. It is shown that this assumption is valid only in noise-dominated environments. When interference is dominant, the assumption yields excessively high error rates. Simulation techniques based on adaptive importance sampling (IS) are developed for this classical problem. However, they are of sufficient generality to be applicable to any form of signalling in interference situations. Several new results are presented, and these can be used to calculate the cellular capacities of wireless systems. Some of the IS results have been validated using numerically computed analytical formulas.