Radio resources in wireless communication systems must be managed. This management is important since the
variations in propagation channel are very fast. The complexity in the cellular system periodically contributes to different
interference levels which ultimately resulting in the degradation of the system capacity. Transmitted power control is an
efficient technique to mitigate the effect of interference, thereby solving the near-Far problem and preserving the battery
life. Thus, an effective implementation of different power control algorithms in cellular radio communication systems can
offer a significant improvement in the quality of service (QoS) to all the users. The choice of an appropriate power control
algorithm is important to increase the overall efficiency of the system. A linear quadratic Gaussian (LQG) power control
strategy is derived and compared with other approaches. Simulation results show that the uplink channel variations do not
destroy the stability of these power control structures. However, delays in the closed-loop paths can severely affect the
stability and performance of the resulting feedback schemes. It is also shown that the use of multiuser detection at the base
station can bring significant improvements to the performance of power control.
Keywords: Code-division-multiple-access systems, Distributed power control, LQG control, Delays.
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