Digital Self-Interference Cancellers for In-Band Full-Duplex Systems with High-Power Amplifiers

In-band full-duplex (IBFD) communication enables simultaneous transmission and reception in the same frequency band. It offers improved spectral efficiency and is considered a promising mode of operation for future wireless networks. However, in IBFD, the transmission signal feedback creates strong self-interference, requiring interference cancellation. Previous studies have proposed digital cancellation using polynomial models or neural networks; however, experimental verifications have been assumed for their implementation on user equipment with low-output amplifiers to ensure linearity. Therefore, in this study, we evaluated the performance of various digital cancellations using a high-power amplifier with a 6 W -class Gallium Nitride high-electron-mobility transistor (GaN HEMT) for implementing IBFD systems at the base or relay stations. The performance of digital self-interference cancellation (DSIC) in a channel using the embedded GaN HEMT PA indicates that the IBFD system can be effectively utilized in base stations and relay stations. These findings offer insights for implementing a versatile IBFD system, a key technology poised to shape the future of wireless networks.