A Unifying View On Energy-Efficiency Metrics In Cognitive Radio Channels

International audienceThis paper analyzes three of the most popular energy-efficiency metrics in wireless communications using a common unifying framework. The target application is a cognitive radio system composed of a secondary user whose goal is to transmit in an optimal energy-efficient manner over several available bands under the interference constraints imposed by the presence of the primary network. The optimal allocation policies maximizing these energy-efficiency metrics are the Pareto-optimal points lying on the optimal tradeoff curve between the rate maximization and power minimization bi-criteria joint problem. Using this unifyingframework, we provide several interesting parallels and differences between these metrics and the implications w.r.t. the optimal tradeoffs between achievable rates and consumed power. Our results provide elements allowing one to choose between these efficiency metrics