Power management for multirate DS-CDMA systems with imperfect successive interference cancellation

In this paper, we address the issue of power distribution and decoding order in the uplink side of a multirate code division multiple access (CDMA) system based on linear successive interference cancellation (SIC). First, the closed form expressions for the required received powers at the base station, in order to achieve the users bit rate and quality of service (QoS) requirements, is derived. Then, we investigate the problem of optimal decoding order of the users under imperfect interference cancellation condition and show that optimum decoding order of users, unlike the case of perfect SIC, is a function of their requested SINR values in addition to their path gains. Finally, we derive new criteria for decoding order of users in multirate SIC-based CDMA systems.