Cooperative spectrum sensing with censoring of cognitive radios in presence of log-normal shadowing under majority logic fusion

Abstract

Performance of cooperative spectrum sensing (CSS) has been assessed in presence of log-normal shadowing. Cognitive radio (CR) users which employ energy detectors (EDs) are censored depending on the quality of radio channels between them and a fusion center (FC). A training based channel estimator is used at the FC to estimate the log-normal shadowing coefficients characterizing the channels between the CR users and the FC. Each CR makes a hard decision about primary user (PU) using energy detection and transmits the information to FC using BPSK signaling if the CR user is selected to transmit. A majority logic fusion rule is applied at the FC for estimating the performance in terms of missed detection and total error probability for both perfect and imperfect channel estimation. The performance of CSS has been evaluated for various probabilities of false alarm, reporting and sensing channel SNR values.