The energy efficiency optimization based on dynamic spectrum sensing and nodes scheduling in cognitive radio sensor networks

Nowadays, cognitive radio sensor networks are facing the inherent energy constraint and spectrum resource scarce problems. Hence in this paper, novel spectrum sensing and nodes selection methods are investigated to jointly optimize the energy and spectrum efficiency. Firstly, to shorten sensing time and save unnecessary spectrum sensing energy, a dynamic censored spectrum sensing scheme is employed to decide when to stop sensing. Then a priority-based sensor node scheduling algorithm in cooperative spectrum sensing is proposed to balance the trade-off between energy efficiency and spectral efficiency. Through mapping discrete parameters into continues real domains, we could decide which nodes are selected for spectrum sensing at an lower complexity. Simulation results demonstrate that significant energy and spectral efficiency could be achieved through the proposed methods.