DS-CDMA receiver using exponentially weighted despreading waveforms

Abstract

This paper presents a DS-CDMA receiver using exponentially weighted despreading waveforms (WDW). The chip weighting waveforms are designed for the purpose of multiple access interference (MAI) rejection by emphasizing the transitions of the received signal of interest. The WDW is determined only by one parameter, which leads to easy tuning of the WDW in practice to achieve the best performance. As a result, we show that the proposed receiver can reject MAI without knowing co-user's spreading codes, timing, and phase, and hence increase system capacity. Analysis and numerical results show that the proposed receiver outperforms the conventional receiver especially when MAI is significant. Finally, a discussion on the effect of bandlimited spreading signals is also given on the practical implications of the proposed technique.