Two-stage detectors based on multiple Antennas with Adaptive Double-Threshold in Cognitive Radio Networks

In this paper, we propose a two-stage spectrum sensing (SS) scheme in cognitive radio networks (CRN). First stage consists of multiple antennas (M) based energy detector (ED) with fixed single threshold (MA_ED_FT) and if required, second stage comprised of ED with adaptive double threshold (ADT) is invoked. Numerical results show that proposed scheme optimizes detection performance and outperforms the cyclostationary based sensing method by 33 % at signal to noise ratio (SNR) setting of as low as – 10 dB with M = 2. Further, it is shown that the proposed scheme yields smaller sensing time in the order of 6.2 ms at 20 dB SNR.