Improvement of sequential-test-based cooperative spectrum sensing systems in band limited control channels

In a cooperative spectrum sensing system, many nodes perform spectrum sensing and report their decisions to one fusion center via control channels. This paper considers efficient use of the frequency band for the control channels. For this purpose, sequential-test is introduced for the local decision at each node. With this scheme, the transmission timing of the reports from the nodes becomes at random and necessary maximum bandwidth for the control channels decreases. Numberical results show that this sequential-test-base-scheme not only decrease the number of simultaneous reports but also improves sensing reliability. For further improvement, this paper also introduces a decision scheme at the fusion center based on probabilistic features of the reports from the nodes.