Spectrum Sensing Performance with Adaptive Threshold in MIMO Cognitive Radio

Cognitive radio (CR) is the key technology that provides to use frequency spectrum effectively. Spectrum sensing, a critical function of CR, detects spectrum holes. Energy based detection (ED) is the most preferred spectrum sensing technique by researchers because it only requires the energy of received signals. The sensing performance of the ED is mainly based on the wireless communication channel. The channel environment is continuously varying in time. It is therefore difficult to detect primary user's signal with a fixed threshold when the energy of received signal is affected by disturbances such as fading, shadowing, noise and interference. In this study, ET sensing performance based on adaptive threshold value in cognitive radio with MIMO technology has been investigated in terms of the number of antennas at the receiver and the transmitter side, the number of multipath, the speed of mobile receiver and modulation type parameters. The simulation results show that the adaptive threshold value provides better detection performance than the fixed threshold value especially at low SNRs.