Power Control for Wideband Cellular Wireless Systems with Link Adaptation

摘要

Power control is an important radio resource management technique to enhance the spectral and power efficiency of wireless systems. However, most power control schemes proposed in the literature consider only narrowband cases, where users are accommodated by a single channel. Next-generation wireless systems aim to provide the mobile users multimedia applications and services, which often have heterogeneous QoS specifications, and demand more bandwidth than voice. In this paper, we explore the power control issue for wideband cellular wireless systems with link adaptation. Each user arriving to the system is associated with a specific minimum rate requirement. By evaluating the availability of the channels, we decide which channels and what SIR target (or equivalently what bit rate) for each chosen channel to sue for this user. The objective is to save power and avoid too many channels being occupied by a user while the minimum rate requirement is satisfied. Since this problem is a nonlinear integer program problem with large search space. We propose a heuristic scheme to solve it online. With the SIR target being determined, each channel can independently adjust the power level using any distributed power control algorithm to achieve the target.