Energy efficient wireless sensor network assisted spectrum sensing for cognitive radio network

The Cognitive Radio (CR) technology is an emerging technology in order to solve the spectrum scarcity problem in the future wireless communication networks. Spectrum sensing which enables dynamic spectrum is found to be one of the most complex and power intensive tasks in a CR. Out of various techniques by which energy efficient spectrum sensing can be done employing a dedicated sensor network for spectrum sensing is given focus in this paper. The proposed architecture consists of a dedicated wireless sensor network assisting ad hoc mobile cognitive radios to sense the spectrum. The sensor nodes within the communication range of each cognitive radios forms clusters around the cognitive radios to sense the spectrum. These clusters are again divided into disjoint subsets to further improve energy efficiency. Only one subset is made active at a time to sense the spectrum. A special subset formation algorithm is proposed to aid static CR spectrum sensing. The use of double threshold censoring at each sensor nodes is also employed to save transmission energy. The improvement in network lifetime and energy efficiency is shown through simulations.