Joint optimal energy-efficient cooperative spectrum sensing and transmission in cognitive radio

In order to improve the energy efficiency (EE) in cognitive radio (CR), a joint optimal energy-efficient cooperative spectrum sensing (CSS) and transmission in multi-channel CR is proposed in this paper. EE is described as a tradeoff between the throughput and the entirely consumed power. A joint optimization problem is formulated to maximize EE by jointly optimizing local sensing time, number of cooperative sensing secondary users (SU), transmission bandwidth and power. A combined optimization algorithm of bi-level optimization, Polyblock optimization and Dinkelbach's optimization is proposed to solve the proposed non-convex optimization problem effectively. The simulation results show that, compared with throughput maximization model (TMM), the energy efficiency maximization model (EEMM) improves EE of the CR system and limits the excessive power consumption effectively.