Efficient integration of multi-rate traffic for 3rd generation DS-CDMA systems

We address the issue of efficient integration of multi-rate traffic supported by third generation DS-CDMA systems. We have previously proposed the notion of line rate (adjusted data rate before spreading) to incorporate traffic with a wide range of source rates. Each selected line rate will support a group of multi-rate traffic. We evaluate the impact of line rate(s) selection on the forward link capacity of a system with integrated/mixed-rate traffic. We first derive the methodology of evaluating the capacity of mixed-rate traffic in the forward link. Our focus is to investigate the effect of processing gain and activity factor (resulting from a selected line rate) on the capacity of different traffic types. We also address the issue of Walsh-Hadamard codes usage of different length (at each selected line rate) and its impact on line rate selection. Our analysis provides insight into the use of line rate(s) for traffic integration and optimal selection of line rate(s).