Zone-Based Distributed Sensing Scheme in Decentralized Cognitive Radio Networks

In cognitive radio networks, secondary users conduct local sensing to use underutilized spectrum bands. However, every secondary user's local sensing usually gives rise to much sensing overhead. Moreover, a globally synchronized quiet period cannot be determined in a decentralized network. In this paper, we propose a zone-based distributed sensing scheme, in which multiple secondary users alternate in local sensing and share the results with others. To do that, we define a sensing zone in which one's sensing results are sharable with others. Moreover, a secondary user can determine its quiet period schedule efficiently while performing the proposed sensing. Numerical analyses and computer simulations show that our proposed sensing achieves the significantly reduced sensing overhead as well as the improved channel access opportunity.