Reducing Dynamic Power Consumption in Next Generation DS-CDMA Mobile Communication Receivers

Abstract

Reduction of the power consumption in portable wireless receivers is an important consideration for next-generation cellular systems specified by standards such as the UMTS, IMT2000. This thesis explores the design-space for reducing the dynamic power dissipation in a RAKE receiver for the Direct Sequence Code Division Multiple Access (DS-CDMA) downlink. Starting with a reference implementation of the DS-CDMA RAKE receiver, we demonstrate design methodologies for achieving significant power reduction, while highlighting the corresponding performance trade-offs. At the algorithm level, we investigate the impact of reduced precision and arithmetic complexity on the performance of the DS-CDMA RAKE receiver. We then present architectures for implementing the reference and reduced complexity DS-CDMA RAKE receivers, and analyze these architectures with respect to their dynamic power dissipation. Finally, we analyze clock-gating techniques for reducing the activity rate in both the architectures to achieve further power reduction.