Analysis of QS-CDMA over frequency selective time non-selective Nakagami-m fading channels

Abstract

In this work, Symbol Error Rate (SER) performance of Quasi Synchronous (QS) CDMA system over frequency selective time non-selective multipath Nakagami-m fading channels is obtained for M-ary Phase Shift Keying (MPSK) signaling, deterministic spreading sequences and different, chip waveforms with a maximal ratio combiner (MRC) at the receiver. We show that the performance of QS-CDMA will be as good as or slightly better than the synchronous performance of Direct Sequence (DS) CDMA when the maximal allowed time offset does not need to be less than 0.2 for Rectangular and 0.7 for Raised-Cosine chip waveform. With this flexibility of maximal allowed time offset, the complexity of synchronization task is reduced.