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Zone-based spectrum sensing in cognitive radio

Dynamic access to spectrum requires detecting the free spaces in close proximity. Since non-cooperative sensing methods cannot satisfy most of the basic requirements, different cooperative sensing algorithms have been proposed to overcome this problem. In the previous works, multiple secondary users cooperate to achieve better primary user detection. However, taking into account the measurements from distant users actually aggravates the detection decision. In this paper, we propose the Zone-based Sensing (ZoneS) method, which is a distributed cooperative sensing method that circumvents the problems that arise from the cooperation between distant nodes. The simulations are performed with different parameters and with majority cooperation rule for the users in each zone. The false alarm, missed detection, blocking and dropping probabilities, and channel utilization are examined to assess the effectiveness of ZoneS. The proposed method enables the utilization of spectrum bands that would be left unused otherwise, while keeping the probabilities of missed detection and false alarm bounded. Furthermore, the coordination among secondary users is achieved without any overhead.