Quickest Detection of Propagating Signals for Flexible Radio Spectrum Use

The design of efficient algorithms for the detection of propagating spatial phenomena is of importance in many fields. Relevant applications can be found in flexible radio spectrum use in radar and wireless communication, Internet of Things, and environmental monitoring. In this paper, we introduce a novel Bayesian procedure for rapid detection of changes in spectrum occupancy in flexible spectrum use systems such as cognitive radio. The primary user primary user starts to transmit at an unknown time and location a signal that propagates obeying the laws of physics towards sensors observing the spectrum. The proposed procedure takes the spatial structure and propagation dynamics of the signal properly into account, and therefore achieves smaller average detection delay (ADD) than existing approaches. In simulations, we also consider a minimax approach applicable in instances where the statistics of the primary user's signal are not perfectly known.