Consensus-based Spectrum Sensing in Cognitive Radio Networks

In this work, we analyze a distributed cooperative spectrum sensing scheme where N secondary users (SUs) of a cognitive wireless net-work make a joint decision on the primary user (PU) presence based on an agreement reached through interchanging of SU’s individual decisions. The operational protocol assumes that each SU updates the personal de-cision by using the “K-out-of-N” rule, and the network detects the PU if the nodes reach the consensus. The problem of forming a joint opinion becomes challenging because a SU makes its personal decision based on local observations distorted by a wireless propagation medium. In this paper, we analyze statistics of factors affecting the algorithm efficiency and obtain sufficient conditions of reaching consensus. The presented analysis takes into account possible node disconnections caused by poor propagation conditions.