Performance of adaptive power control in presence of loop delays

In this paper, performance of adaptive power control algorithms for Universal Mobile Telecommunication System (UMTS) in the presence of power control loop delay is studied and analysed. Simulation results show that although adaptive algorithms can achieve better performance than a fixed stepsize power control (FSPC) algorithm when the total delay is equal to one power control cycle, their performance in the presence of an additional delay is worse than the performance of FSPC under the same condition. Based on the simulations results, we recommend that it is crucial to consider effects of additional loop delays in an adaptive power control algorithm design phase; otherwise the algorithm will not work in practice.