Wideband Full-Duplex MIMO: A 5*5 Example Across 12.5-13.0 GHz with Baseband 100 MHz

Abstract

Full-duplex wideband wireless radios with MIMO is a challenging open problem in communications. The adoption of a pair of arrays for physical symmetry-based passive cancellation of self-interference between antenna elements is demonstrated in the FR3 band. Up to 12 dB of additional self-interference cancellation (SIC) is observed. Further, machine learning-based DSP is used to mimic the nonidealities of each power amplifier in the MIMO system, thereby allowing additional 22 dB of digital SIC. A linear FIR MIMO filterbank is envisaged for cancelling environmental reflections across the MIMO interface. Work on both MIMO-RF and DSP-based cancellation is reported in the FR3 range of 12.5-13.0 GHz band with a DSP bandwidth of 100 MHz on Xilinx RF-SoC ZCU-111.