Full-duplex spectrum sensing in broadband power line communications

We address the issue of electromagnetic interference between power line communication (PLC) and non-PLC services by using full-duplex spectrum sensing for cognitive PLC. Contemporary broadband PLC (BB-PLC) standards allow PLC devices to dynamically use idle spectra that are allotted to non-PLC services, like broadcast radio. Traditional spectrum sensing techniques operate in a half-duplex manner, and thus provide sub-optimal sensing efficiency. In this paper, we propose the use of in-band full-duplex (IBFD) operation to allow simultaneous data transmission and spectrum sensing, and eliminate all sensing-only and other wait times involved in conventional spectrum sensing operations. We first show that using the state-of-the-art IBFD solution yields inaccurate spectrum sensing performance due to non-negligible residual self-interference. We therefore propose multiple solutions to address this problem. We show through simulation results that our proposed solutions provide sufficient self-interference cancellation to achieve nearly the same spectrum sensing accuracy as that obtained in a half-duplex operation.