Performance of cooperative spectrum sensing with censoring of cognitive radios in Rayleigh fading channel

Performance of cooperative spectrum sensing has been assessed in presence of Rayleigh fading. Cognitive radio (CR) users which employ energy detectors are censored depending on the quality of radio channels between them and a fusion center (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 training based channel estimator is used at the FC to estimate the complex Gaussian fading coefficients characterizing the channels between the CR users and the FC. This channel state information (CSI) on fading coefficients is used for censoring the CR users. A majority logic fusion rule is applied at the FC for estimating the performance in terms of missed detection probability (P_m). Probability of missed detection has been evaluated for both perfect and imperfect channel estimation for various probabilities of false alarm (P_f), reporting and sensing channel SNR values.