Some Results on Pulse Shaping in DS-CDMA Systems
Pål Orten, Arne Svensson · 1997
DS-CDMA is evaluated for rectangular pulse shaping and square root raised cosine pulses with different roll off factors. Rectangular pulses are found to be better even with close adjacent channels. With synchronization error in the order of 10% of a chip interval, square root raised cosine pulses outperform the rectangular pulse. I. INTRODUCTION Direct Sequence CDMA (DS-CDMA) has been subject to much research in recent years as it is a promising multiple access scheme for third generation mobile systems. Most work examining the performance of DS-CDMA systems assume rectangular chip shapes since this simplifies the simulation models, and no oversampling is needed, reducing the simulation complexity. In systems to be implemented however, some pulse shaping other than rectangular is normally applied to limit the out of band power. In [1] optimum pulse shapes are designed that minimize multiple access interference (MAI) given a restriction on out of band power (OBP), and chip pulses are li...