On the capacity of CDMA with linear successive interference cancellation

Abstract

Combined power control and interference cancellation in CDMA systems can be a very efficient resource management tool. While conventional power control tries to maintain equal received power or balanced SIR, successive interference cancellation (SIC) in multi-user detection (MUD) relies more on the disparities between the powers of the different users. The combination can save more power into the system and thus has room for better capacity. This paper investigates the interaction between power control and linear SIC in a single rate CDMA system and its impact on the system capacity. The obtained results show that interference cancellation can improve the capacity of CDMA and relax power control requirements. The full integration of power control and SIC is shown to provide excellent resource management in CDMA systems. Limited cancellation can be a good solution for CDMA systems as it provides considerable capacity gain with reduced complexity. An upper bound on the system capacity as a function of the number of canceled signals is derived. Investigation of the optimum decoding order ipower controlpower controls also provided is this paper.