A Nash-based power control game for green communications via cognitive radio networks

The main challenge in green communications is to effectively and efficiently utilize the radio resources, particularly energy and spectrum. Hence, cognitive radio technology is introduced with the ability of allowing secondary users (SUs) to share a band of spectrum which is not fully exploited by the primary users (PUs). Power control is one of the main components in green cognitive radio technology, not only to ensure that the SUs transmit sufficient power to achieve the satisfactory quality of services (QoS) without excessive interference to other SUs, but also need to alleviate negative effects to the PUs. In this paper, a Nash-based power control game (NPCG) together with a novel interference mitigation algorithm (IMA) are proposed for SUs to efficiently trade off their QoS for better energy efficiency. The weighting constant introduced in the IMA plays a vital role to alleviate the interference produced by the SUs so that it is always below the interference temperature threshold. Simulation results show that the NPCG algorithm incorporated with the IMA not only can achieve rapid convergence, but also provide a good tradeoff between QoS and energy efficiency.