Optimization of Cooperative Spectrum Sensing with an Improved Energy Detector over Imperfect Reporting Channels

Optimization of cooperative spectrum sensing with an improved energy detector in each cognitive radio (CR)over imperfect reporting channels is discussed in this paper. The improved energy detector compares an arbitrary positive power p of the amplitude of the received samples of the signals of a primary user (PU)with a threshold to make a decision. The binary decision of each CR is forwarded over an imperfect reporting channel to a fusion center which makes a final decision on the presence of the PU. We obtain an expression of the total error rate of detection of a spectrum hole for this cooperative set-up. The optimized values of the normalized threshold and p in each CR and optimal number of CRs required for the decision are obtained by minimizing the total error rate. It is shown by simulations that the proposed scheme significantly outperforms an existing scheme using the conventional energy detector.