Combined censoring and weighted fusion based spectrum sensing with improved energy detector

In the present article, the cooperative spectrum sensing with a weighted fusion (WCSS) scheme has been analyzed in Rayleigh fading. Cognitive radio (CR) uses an improved energy detector (IED) with several antennas. Antenna selection diversity combining (SC) is performed at each CR on the basis of the values of decision statistics measured from different antennas at IED. Every CR takes 1-bit decision regarding primary user (PU) and sends its decision to fusion center (FC) with binary phase shift keying (BPSK) signaling if FC selects that CR to send. The FC estimates weight factors of selected CRs with the help of a profile of average SNRs and incorporated with decisions of each selected CR. The missed detection performance is evaluated for different values of improved detector parameter with different number of antennas, average SNRs of sensing (S) and reporting (R) channels. WCSS with censoring performance is also analyzed for perfect and imperfect estimation cases. Combined censoring and weighted fusion significantly improves the spectrum sensing performance.