Cognitive Radio Network With Energy-Harvesting Based on Primary and Secondary User Signals

Cognitive radio (CR) provides a radio-access method for unlicensed/secondary users to share the spectrum of licensed/primary users. To improve the energy efficiency of CR networks, we propose an energy-harvesting-aided spectrum sensing and data transmission scheme in this paper. In the proposed scheme, the individual sensing and the cooperative sensing of multi-users are combined corresponding to the strong and weak signal of primary users. Meanwhile, the transmission signal of local decisions in the cooperative sensing and the strong signal of primary users are harvested as RF energy by secondary users. In order to improve the performance of spectrum sensing and energy harvesting, we formulate a multi-objective optimization problem that jointly maximizes the detection probability of the presence of primary user and minimizes the false alarm probability while limiting the least harvested energy and the interference from secondary users on the primary receiver. The multi-objective optimization problem is solved by transferring it into a single objective problem. The single objective problem on the parameters without certain range is transferred into the problem on the parameters with certain range to obtain the final solution. Numerical results prove the effectiveness of our proposed scheme, that is, the interference from primary users on secondary users can improve the global detection probability and the harvested energy at secondary users.