Distribution of SIR and performance of DS-CDMA systems in lognormally shadowed Rician channels

New closed form expressions for the probability density function and the cumulative distribution function of the ratio of L/sub S/ Rician signals to L/sub I/ Rician interferers, so-called signal-to-interference (SIR) power ratio, are derived. These SIR distributions are then used to evaluate the error probability and capture probability of direct sequence code division multiple access systems operating in Rician faded channels with lognormal shadowing. The influence of various system parameters such as the Rice K factor, shadowing spread, number of interferers, and spread spectrum processing gain on the system performance are analyzed and discussed.