Cooperative spectrum sensing based on Majority decision under CFAR and CDR constraints

This work addresses the impact of sensing decision fusion rules and operative constraints on the performance of hard decision cooperative spectrum sensing schemes for cognitive radio networks. The work focuses on cooperative spectrum sensing under two sensing operating modes: the Constant False Alarm Rate (CFAR) and the Constant Detection Rate (CDR) mode. Analytical solutions for network probability of false alarm and of detection under the assumption that all nodes share the same individual probability of false alarm or detection, respectively, are reviewed, and corresponding exact analytical expressions for such probabilities are expressed for OR and AND fusion rules. In the case of the Majority fusion rule novel analytical approximations for the required values of individual probability of false alarm in CFAR mode and individual probability of detection in CDR mode, respectively, are derived. The validity of the approximations is confirmed by means of numerical simulations, and the impact of errors in the estimation of average SNR for the signal of the primary user at the receivers of the cognitive network is analyzed by network simulations.