Energy-efficent cooperative spectrum sensing for cognitive sensor networks with energy harvesting

Cognitive sensor networks introduce the cognitive radio technology to improve the spectrum efficiency, which requires more energy for spectrum sensing and will decease network lifetime. Energy harvesting is a promising technology to address the issue by allowing sensor node to harvest energy from environment. This paper proposes a cooperative spectrum sensing scheme to select sensing node for cognitive sensor networks with energy harvesting. In the scheme, the sensing node selection problem is formulated to a non-convex 0-1 integer programming problem, which is NP-hard. To solve it, the discrete 0-1 programming variables are mapped into continues to obtain an equivalent convex optimization problem. Then, a priority based sensing nodes selection algorithm is proposed to reduce the complexity of solving the convex problem. The optimal sensing node set is determined based on the nodes' sensing priorities. Simulation results verify that the proposed algorithm is effective in balancing network energy consumption and prolonging network lifetime.