In-Band Full-Duplex Antenna Beamforming and Synchronization for Self-Interference Mitigation: Multi-Tile RFSoC Testbed Design and Deployment

This paper presents a newly developed in-band full-duplex (IBFD) communication and sensing testbed utilizing digital beamforming on the advanced Xilinx ZCU216 Radio Frequency System-on-Chip (RFSoC) platform, featuring 16 DACs and 16 ADCs with 14-bit resolution divided into four tiles. Key design and deployment challenges include achieving precise phase synchronization across multiple RFSoC tiles (due to independent clocks causing random phase shifts) and mitigating self-interference (SI) caused by strong mutual coupling effects between closely spaced transmitting (Tx) and receiving (Rx) antenna arrays. To address these challenges, we employed a Tx beamforming algorithm for maximum antenna gain and an Rx beamforming method to maximize the signal-to-self-interference ratio (SSIR) at the receiver output. Specifications of two 1 x 5 Vivaldi antenna arrays (3–6 GHz), integrated into our RFSoC-based testbed, and the multi-tile synchronization (MTS) framework were established to meet IBFD performance requirements. The deployment involved implementing the beam-forming algorithms, configuring the Tx and Rx arrays, and ensuring calibration and synchronization across RFSoC tiles. Experimental results demonstrate over 80 dB SI suppression with half-wavelength separation (@6 GHz) between the Tx and Rx arrays, highlighting the testbed's potential for applications in 6G integrated communication and radar sensing.