Resource allocation and capacity in wireless CDMA networks using adaptive power control and antenna array multiuser receiver

Abstract

In this paper we developed a framework for resource allocation in multi-class traffic CDMA system using adaptive power control and antenna array multiuser receiver. We devised a new scheme in which both transmit power and receiver filter adapt to the time-varying channel state. An antenna array multiuser receiver that jointly processes received signal vectors from multiple antennas and maximizes the signal-to-interference ratio for each user is proposed. It is combined with adaptive power control based on target SIR for each user. Our scheme can support multi-class traffic with different SIR requirements and guarantee their quality of service in multipath fading environment. A theoretical bound is derived to characterize capacity of CDMA system using adaptive power control and antenna array multiuser receiver in multipath fading environment. Simulations show that actual system capacity in multipath finding environment is close to the theoretical bound at large power constraint. Capacity at various power constraints can be characterized by a notion of bandwidth utility. It is also demonstrated that the antenna array multiuser receiver is quite effective in increasing capacity of users with higher SIR requirement and lower power constraint.