Effect of system imperfections on BER performance of CDMA correlator receiver

Direct sequence spread spectrum CDMA systems is receiving considerable attention in the field of mobile communication. The bit error rate performance of a code division multiple access correlator type receiver with imperfections in power control, carrier phase estimate and spreading code phase estimate is analyzed. Imperfection in power control is taken into account by modeling the received signal power as a log normally distributed random variable. The phase estimate errors are modeled as zero mean Gaussian random variables. It is shown that the performance of such a receiver significantly degrades when variance of power control imperfection is above 0 dB, standard deviation of the code phase error is above 0.01 and mean square error of carrier phase estimate is above 0.01. The communication system considered is a microcellular system operating in an indoor environment where K transmission stations are asynchronously transmitting over their individual multipath fading channels to the base station receiver