Decentralized cooperative detection based on averaging consensus

In this paper, decentralized spectrum sensing in a network of multiple cooperative cognitive nodes is considered. Based on the averaging consensus protocol, we propose a decentralized implementation of the energy detector, which is conventionally applied for spectrum sensing in a centralized fashion. The exact (non-asymptotic) null distribution of the decentralized energy detector test statistic is derived and used to compute the test threshold. The communication overhead of our proposed detector is low compared to the existing decentralized spectrum sensing algorithms. Moreover, we extend the energy detector to the problem of detecting the number of sources impinging onto a network of sensors. Simulation results demonstrate that using a moderate number of averaging consensus iterations, the extended energy detector is able to detect the correct number of sources with high probability.