Cooperative spectrum sensing with censoring of cognitive radios and improved energy detector under majority logic fusion

In this paper, performance of cooperative spectrum sensing (CSS) has been assessed in the presence of Rayleigh fading. Cognitive radio (CR) users which employ improved energy detectors (IEDs) 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 fading coefficients characterizing the channels between the CRs and the FC. The CRs utilize selection combining (SC) of the decision statistics obtained by IEDs with multiple antennas for making hard decisions about the presence of primary user (PU) and transmit the information to the FC using BPSK signaling if the CR is selected to transmit. The majority logic fusion 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 under different channel and network parameter conditions.