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

New closed form expressions for the probability density function (PDF) and the cumulative distribution function (CDF) of the ratio of L/sub S/ Rician signals to L/sub I/ Rician interferers, so called signal to interference ratio (SIR), are derived. These SIR distributions are then used to evaluate the bit error rate (BER) performance of direct sequence (DS) code division multiple access (CDMA) systems, operating in lognormally shadowed and Rician faded microcellular mobile radio channels. The influence of various system parameters on the BER performance, such as the Rice K factor, shadowing spread, and the number of interferers, is analyzed and discussed.