Evaluation of cooperative sensing for perfect reporting channels using dynamic detection threshold

The most important components in cognitive radio (CR) system is spectrum sensing. In this paper we propose a novel method to determine the optimum number of Secondary users (SUs) necessary in the cooperative spectrum sensing environment for perfect reporting channel. At first the threshold selection is carried out considering present conditions of noise levels. The noise variance is estimated using Maximum likelihood estimator. Secondly the optimum number of SUs required in cooperative sensing are determined using the proposed scheme of threshold selection. The results show that the proposed method provides detection probability very close to the clairvoyant detector with known parameters. The optimum number of SUs and the error rates achieved in Cooperative sensing using the proposed method are close to that obtained by the classical detection.