Adaptive Blind Spectrum Sensing for mmWave Full Duplex Cognitive Aerial BS

This paper focuses on the utilization of unmanned aerial vehicles (UAVs) in the context of 5G and beyond-5G cellular mobile communication systems. In particular, UAVs as aerial base stations offer flexibility and improved wireless capacity, creating a vertical heterogeneous network. However, the high number of aerial and ground devices as well as the need of flexibility and the lack of spectrum availability pose some challenges that need to be addressed. Toward this goal, we propose here to exploit the capabilities of cognitive radio and full-duplex technologies. An adaptive signal whitening approach using the recursive least squares method is proposed to handle the time-varying colored noise, represented by the residual self-interference in an urban UAV scenario. Numerical simulations demonstrate that the proposed adaptive whitening approach outperforms previously proposed methods in terms of detection performance while maintaining the constant false alarm ratio property