Full-Duplex Spectrum Sensing Scheme Based on Phase Difference

With recent breakthroughs in full-duplex radio, there is a growing trend to combine it with cognitive radio. Thus the topic of spectrum sensing in full-duplex scenario is addressed in this paper. Firstly, the concept of full-duplex spectrum sensing and its advantage over traditional half-duplex spectrum sensing are analyzed. Then a correlation based least square algorithm is formulated to cancel out self-interference, in which no preamble is required. We notice that the phase distribution of noise differs greatly from that of noise-perturbed signals. Therefore, a novel spectrum sensing scheme using phase difference as test statistics is introduced. Its theoretical performance is also analyzed by approximating the test statistics as Gaussian distribution. The proposed detector is simple and immune to noise uncertainty due to the independence of its threshold on noise power. Simulation results show that robust sensing performance can be achieved in full-duplex scenario using correlation based least square and the phase based sensing scheme.