Optimal cooperative spectrum sensing strategy in cognitive radio networks exploiting RF-energy harvesting

In this paper, we consider energy harvesting cognitive radio networks (CRNs) where each secondary user (SU) has no fixed power supplies and extract energy only via harvesting energy by Radio Frequency (RF) provided by the control center (CC). Cooperative spectrum sensing is employed to improve the sensing performance. The spectrum sensing policy should maximize the probability of discovering and utilizing the spectrum opportunities while ensuring the specified primary user (PU) protection level. For a homogeneous scenario, the optimal sensing probability of each SU is obtained to maximize the CC throughput while satisfying the energy causality and PU collision constraints. An iterative algorithm is proposed to obtain the optimal charging time τ_e. Numerical results depict that in an energy constrained scenario, we can benefit from the optimal cooperative spectrum sensing policy in terms of enhanced PU detection.