Optimal Number of Cognitive Users in $K$ -Out-of- $M$ Rule

Abstract

In this letter, we obtain a generalized expression for the optimal number of cognitive users M for the K-out-of-M rule that minimizes the Bayes risk at the fusion center over noisy control channels. We show that many existing and new results for optimal M are special cases of the proposed solution. Numerical results are presented using energy detector. However, the expressions for optimal M obtained in this letter are applicable to any detector used in cooperative spectrum sensing.