Capacity of multi-class traffic CDMA system with multiuser receiver

In this paper we study resource allocation and capacity of CDMA system using multiuser receiver to support multiple classes of traffic with different data rates and bit error rate requirements. We developed a new resource allocation scheme using adaptive power control and multirate multiuser receiver to guarantee users´ quality of service requirements in multipath fading environment. A multiuser receiver that maximizes the signal-to-interference ratio (SIR) for each symbol is proposed for multirate CDMA system. It is combined with adaptive power control based on target SIR to provide different quality of service for multiple-data-rate traffic. A theoretical bound is derived to characterize capacity of multi-class traffic CDMA system using the multiuser receiver. Simulations show that actual system capacity in multipath fading environment is close to the theoretical bound at large power constraint. It is also demonstrated that the multiuser receiver is quite effective in increasing capacity of users with higher data rate and lower target bit error rate