Distributed cooperative spectrum sensingwith double-topology

This paper addresses the problem of correlation due to redundancy in cooperative spectrum sensing networks and proposes an algorithm for topology design which improves significantly detection performance. In a recently proposed two-step distributed scheme, redundancy occurs when some nodes contribute more than once for the consensus decision, leading to correlation and consequently degrading performance in the same way as correlated shadowing. To eliminate this type of correlation, we employ two different topologies, primary and complementary, one for each cooperation step. Topology design is accomplished in a distributed manner by stating criteria for user selection. Results show that the proposed double-topology scheme suppresses redundancy and offers similar performance when compared to the case of independent node contributions.