Fully Distributed Cooperative Spectrum Sensing for Cognitive Radio Ad Hoc Networks

Cognitive radios are indispensable to shift from conventional spectrum assignment to dynamic spectrum access. These are intelligent radios having the capability of sensing the radio environment and reconfiguring the operating parameters dynamically. Recently cognitive radios are considered for ad hoc environment. Cognitive radio ad hoc network have several unique features other than inherited features of ad hoc network like distributed multi-hop architecture, variant network topology and opportunistic spectrum availability. It is required for cognitive radio to find unutilized portion of the spectrum more accurately for successful deployment of cognitive radio ad hoc networks. In cooperative spectrum sensing, multiple cognitive radio users cooperate to detect the presence or absence of primary user to improve the detection performance. Ad hoc networks are dynamic in nature and have no central entity for data fusion. Therefore cognitive radio ad hoc networks need fully distributed cooperative spectrum sensing. In this paper, a gradient based fully distributed cooperative spectrum sensing is proposed for cognitive radio ad hoc networks. The proposed scheme is analyzed from the perspective of reliable sensing and energy consumption. Simulation results show the effectiveness of the proposed scheme.