Yaoguang Wei, University of Minnesota Cliff Sze, IBM Austin Research Laboratory Natarajan Viswanathan, IBM Systems and Technology Group Zhuo Li, IBM Austin Research Laboratory Charles J. Alpert, IBM Austin Research Laboratory Lakshmi Reddy, IBM Systems and Technology Group Andrew D. Huber, IBM Systems and Technology Group Gustavo E. Tellez, IBM Systems and Technology Group Douglas Keller, IBM S...

Different modulation schemes supporting multiple data rates in a Direct Sequence Code Division Multiple Access (DS/CDMA) system are studied. Both AWGN and multipath Rayleigh fading channels are considered. It is shown that the multi processing-gain scheme and the multi-channel scheme have almost the same performance. However, the multi-channel scheme may have some advantages due to near-far res...