Performance analysis of multiple sample based improved energy detector in collaborative CR networks

In the existing literature, a single sample based improved energy detector has been analyzed for multiple antennas based cooperative spectrum sensing. In this paper, we derive the expressions of the probability of false alarm and missed detection of multiple antenna based dual-hop cooperative spectrum sensing scheme which uses multiple samples of the primary user´s signal in the improved energy detector. By minimizing the total error rate (weighted sum of the probability of missed detection and probability of false alarm), we derive a closed-form solution of optimal number of CRs required for dual-hop cooperation. It is shown by simulations that this generalized scheme significantly outperforms the conventional energy detector based spectrum sensing, while keeping quality-of-service in desired limits. A multi-hop cognitive radio network containing multiple antenna based CRs and using an improved energy detector with multiple samples is also analyzed in this paper. It is inferred by analysis and simulation that the error performance of the multi-hop cognitive relaying can be significantly improved by using multiple antennas and improved energy detector.