Millimeter-Wave Full Duplex Radios: New Challenges and Techniques

Equipping millimeter-wave (mmWave) systems with full duplex capability would accelerate and transform next-generation wireless applications and forge a path for new ones. Full duplex mmWave transceivers could capitalize on the already attractive features of mmWave communication by supplying spectral efficiency gains and latency improvements while also affording future networks deployment solutions in the form of interference management and wireless backhaul. Foreseeable challenges and obstacles in making mmWave full duplex a reality are presented in this article along with noteworthy unknowns warranting further investigation. With these novelties of mmWave full duplex in mind, we lay out potential solutions - beyond active self-interference cancellation - that harness the spatial degrees of freedom bestowed by dense antenna arrays to enable simultaneous transmission and reception in-band.