Adaptive power control for wireless communication systems with time-varying delay

Adaptive power control is an effective technique to deal with time delay and channel parameter uncertainty in code-division multiple access (CDMA) wireless communication systems. However, almost all existing adaptive power control algorithms assume that the time delay is known and fixed. This paper investigates adaptive power control of CDMA systems with unknown and time varying transmission delay in communication channels. To compensate for the time-varying delay and reduce the effects of channel parameter uncertainty, a novel adaptive power control algorithm is presented based on time delay and channel parameter estimations. Simulation results are given to demonstrate the effectiveness of the proposed algorithm.