Cooperative change detection using physical layer fusion

This work presents a new approach to spectrum sensing for cognitive radios with multiple sensors under a change detection framework. Physical layer fusion is used at the fusion center in order to implement a cumulative sum based change detection algorithm. Two channel models, AWGN and quasi static block-fading, are considered for the channel between the sensors and the fusion center. Analytical expressions are obtained for determining the false alarm rate and worst case detection delay performance. Simulation results are presented to highlight the performance of the scheme. It is shown that this scheme achieves a performance close to that of a centralized change detection scheme in the case of an AWGN channel.