Distributed Power Control in CDMA Cellular System

In wireless cellular communication, it is essential to nd e ective means of power control of signals received from randomly dispersed users within one cell. E ective power control will heavily impact the system capacity. Distributed power control (DPC) is a natural choice for such purpose, because unlike centralized power control, DPC does not require extensive computational power. Distributed power control should be able to adjust the power levels of each transmitted signal using only local measurements, so that in reasonable time all users will maintain the desired signal to interference ratio. In this paper, we review di erent approaches for power control focusing on CDMA systems. We also introduce state-space methods and linear quadratic power control (LQPC) to solve the power control problem. A simulation environment was developed to compare LQPC with earlier approaches. The results show that LQPC is more e ective and is capable of computing the desired transmission power of each mobile station in fewer iterations, as well as being able to accommodate more users in the system.