On the performance of multi-user DS-CDMA systems over power-line channels

In this paper we propose to implement direct-spread code-division multiple access (DS-CDMA) over powerline channels combined with blanking at the receiver to reduce the effect of impulsive noise (IN). Two spreading sequences are investigated in this study, namely, Walsh-Hadamard and polyphase codes. The impact of different loading scenarios, ranging from light-to full-loading, on the probability of blanking error and output signal-to-noise ratio (SNR) performance is examined. In addition, the optimal blanking threshold that maximizes the system performance is considered for various system loadings and under different IN conditions. Results reveal that the proposed technique is able to provide remarkable output SNR improvement relative to the conventional DS-CDMA system. It is also shown that this enhancement becomes more significant when the number of active users is reduced.