Improved Detection Performance of Cognitive Radio Networks in AWGN and Rayleigh Fading Environments

Abstract

Cognitive radios (CRs) have been recently emerging as prime candidates to enhance spectral efficiency by exploitingspectrum-aware systems which can reliably monitor licensed users’ activities. CR users monitor such activities byperforming spectrum sensing to detect potential white spaces. However, this process of local sensing might be achallenging task in fading environments. The inefficiency of spectrum sensing might cause interference to licensees ifthey are miss-detected by CR users. Thus, cooperative spectrum sensing is proposed as a means to combat fading andimprove the detection performance. However, the detection performance does not improve by such cooperation whenlow-SNR environment is considered. In this paper, cooperative spectrum sensing with PSO-based threshold adaptationis presented to address the aforementioned problem. Simulation results show that the detection performance with PSObasedadaptive detection threshold is improved, particularly, in low-SNR environment.