Novel spectrum sensing scheme in cognitive radio by simultaneously sensing/transmitting at full-duplex Tx and BER measurements at Rx

This paper considers spectrum utilization in cognitive radio (CR) based on both simultaneously adaptive spectrum sensing and transmission at Tx and bit error rate (BER) variation checking at Rx. A novel detecting model is proposed to consider the full-duplex second-user (SU)´s simultaneous sensing and transmitting whether the primary user (PU) is active or not. The probability of detection is provided, on the basis of which the spectrum utilization is derived. With the proposed detecting model, a spectrum sensing scheme with an adaptive window is designed to improve the spectrum utilization. At Rx, the BER variation is used further to detect whether PU is active or not. Simulation results show that i) the probability of detection when SU does not transmit is slightly higher than that when SU transmits, ii) the adaptive window improves the spectrum utilization, and iii) the observation on BER provides a significant improvement on the spectrum utilization.