Photonic-Enabled RF Canceller for In-Band Full-Duplex 5G Networks

Future 5G wireless networks can benefit from the use of in-band full-duplex technologies that allow access to previously unused spectrum by suppressing consequential self-interference. While this interference mitigation is typically achieved using multiple techniques, existing RF cancellation schemes can limit a system's center frequency and instantaneous bandwidth. This paper introduces a unique RF canceller design that uses photonics and a vector modulator architecture to provide a high number of canceller taps with tunable time delays, which allow the canceller to operate over wide bandwidths. A prototype of this concept was built, and successfully demonstrated more than 17 dB of cancellation over a 1 GHz bandwidth centered at 2.5 GHz by utilizing 20 tunable canceller taps.