Transmit Power Efficiency of Fast Transmit Power Controlled DS-CDMA Reverse Link

摘要

Fast transmit power control (TPC) adaptively controls the mobile terminal transmit power so that the instantaneous signal-to-interference plus background noise ratio's (SIR's) of received signals of all users at the base station receiver are kept at the target value to avoid the adverse effect of multipath fading as well as the near/far problem. This paper theoretically analyzes the power efficiency of power controlled DS-CDMA reverse link assuming ideal Rake combining under multi-user and multipath Rayleigh fading environments. The achievable bit error rate (BER) performance is evaluated as a function of average and peak transmit powers required at mobile terminals. The effect of number of resolved paths is discussed. It is shown that the required peak transmit power with fast TPC is larger than that without fast TPC for relatively large BER values; however, when the link is interference-limited, fast TPC achieves significantly larger link capacity.