Sequential cooperative sensing for multi-channel cognitive radios

A sequential cooperative spectrum sensing algorithm is developed for multi-channel cognitive radio (CR) systems. Each CR quantizes the local observations to a single-bit datum per sample per channel, and relays the data sequentially to the fusion center for joint decision. The optimal trade-off between the sensing time and the sensing reliability is sought with the objective of maximizing the overall throughput of the CR system under prescribed “collision” probability constraints. A constrained dynamic programming formulation is developed and a reduced-complexity approximate solution is derived. Numerical tests verify the efficacy of cooperation and sequential processing for spectrum sensing.