| Energy-efficient cross-layer resource management in wireless networks is studied using game theory as a unifying framework. Focusing on multiple-access networks, non-cooperative power control games are proposed in which each user seeks to maximize its own utility while satisfying its quality-of-service (QoS) constraints. The utility function measures the number of reliable bits transmitted per joule of energy consumed, and therefore is particularly suitable for energy-constrained networks. The actions available to each user in maximizing its utility are at least the choice of the transmit power and, depending on the situation, the user may also be able to choose its transmission rate, modulation scheme, receiver type, multiantenna processing algorithm, or carrier allocation strategy. The best-response (i.e., utility-maximizing) strategies and Nash equilibrium solutions for the proposed games are derived. Using the proposed game-theoretic framework, the effects of power control, rate control, modulation, multiuser detection, antenna diversity, and delay QoS constraints on energy efficiency and network capacity are studied and quantified. In addition, the tradeoffs among throughput, delay, network capacity and energy efficiency are analyzed and quantified in a competitive multiuser setting. It is illustrated that game theory is an effective tool for studying cross-layer resource management in wireless networks. |
