Cluster-Based Energy Efficient Cooperative Spectrum Sensing in Cognitive Radios

Spectrum sensing is a crucial measure for cognitive radio networks (CRN) to protect transmission of primary users. Cooperative spectrum sensing is regarded as the most promising method to improve the reliability of spectrum sensing. However, such cooperation also introduces overhead traffic of control signaling and result transmission which consumes more power in battery-operated mobile terminals. In this paper, an energy efficient transmission scheme is proposed. Clustering technique is adopted to save energy consumed in reporting results and exchanging information. All cognitive nodes are separated into a few clusters, and report local decisions to cluster heads to make cluster decisions through some data fusion method. Cluster decisions are forwarded to the common receiver to decide whether the spectrum of interest is idle or not. Simulation results demonstrate that the proposed method shows significant energy saving from 35% to 95% compared with the conventional scheme.