Energy-efficient multi-hop clustering scheme for cooperative spectrum sensing in cognitive radio networks

Cooperative spectrum sensing is introduced to detect vacant frequency bands more accurately for secondary (unlicensed) users without causing any interference to the transmission of primary (licensed) users. Clustering approach is considered as an effective method in cooperative spectrum sensing to tackle the degradation in the performance of spectrum sensing due to fading and shadowing of reporting channel, and also to reduce the control channel overhead when the number of cooperative users becomes very large. In practice, some cluster heads might be far away from the fusion centre, which leads to more energy consumption for reporting their results to the fusion centre, especially in large-scale cognitive radio networks. However, existing studies have not considered this issue. In this paper, we propose a multi-hop cluster-based cooperative spectrum sensing scheme to reduce the power consumption, but at the expense of slight increase in reporting time. The simulation results show that our algorithm can achieve better energy gains as well as less spectrum sensing time than conventional cooperative spectrum sensing algorithms.