Selection of secondary users for cooperative spectrum sensing in cognitive radio networks using discrete stochastic optimization

In this paper, we shall consider the problem of secondary users´ selection for cooperative spectrum sensing in cognitive radio networks. To this end we use the probability of detection as a criterion subject to a false alarm constraint for a linear combination based fusion technique at the fusion center. Owing to the high computational complexity involved in determining the optimal subset of secondary users via exhaustive search, we propose an algorithm based on discrete stochastic optimization that spends most of its time near the global optimizer. The algorithm can further adapt itself to the inherent time varying nature of the underlying wireless communication channel. Finally, we shall demonstrate the efficacy of the proposed algorithm and its tracking ability of variations in the wireless channel conditions via simulation results.