Energy-Efficient Distributed Spectrum Sensing with Combined Censoring in Cognitive Radios

Li FENG  Yujun KUANG  Binwei WU  Zeyang DAI  Qin YU  

IEICE TRANSACTIONS on Communications   Vol.E99-B   No.2   pp.455-464
Publication Date: 2016/02/01
Online ISSN: 1745-1345
DOI: 10.1587/transcom.2015EBP3285
Type of Manuscript: PAPER
Category: Wireless Communication Technologies
cognitive radio networks,  cooperative spectrum sensing,  censor,  fusion center,  green communications,  

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In this paper, we propose a novel censor-based cooperative spectrum sensing strategy, called adaptive energy-efficient sensing (AES), in which both sequential sensing and censoring report mechanism are employed, aiming to reduce the sensing energy consumption of secondary user relays (SRs). In AES, an anchor secondary user (SU) requires cooperative sensing only when it does not detect the presence of PU by itself, and the cooperative SR adopts decision censoring report only if the sensing result differs from its previous one. We derive the generalized-form expressions false alarm and detection probabilities over Rayleigh fading channels for AES. The sensing energy consumption is also analyzed. Then, we study sensing energy overhead minimization problem and show that the sensing time allocation can be optimized to minimize the miss detection probability and sensing energy overhead. Finally, numerical results show that the proposed strategy can remarkably reduce the sensing energy consumption while only slightly degrading the detection performance compared with traditional scheme.