# Beamforming Cancellation Design for Millimeter-Wave Full-Duplex

## TL;DR

This paper proposes beamforming cancellation techniques for millimeter-wave full-duplex systems, enabling simultaneous transmission and reception with high spectral efficiency by mitigating self-interference through directional beam steering.

## Contribution

It introduces novel BFC designs tailored for mmWave hybrid beamforming systems, effectively suppressing self-interference to approach ideal full-duplex performance.

## Key findings

- BFC designs significantly reduce self-interference in mmWave FD systems
- Spectral efficiency approaches that of SI-free FD systems in simulations
- Designs are effective for two different hybrid beamforming scenarios

## Abstract

In recent years, there has been extensive research on millimeter-wave (mmWave) communication and on in-band full-duplex (FD) communication, but work on the combination of the two is relatively lacking. FD mmWave systems could offer increased spectral efficiency and decreased latency while also suggesting the redesign of existing mmWave applications. While FD technology has been well-explored for sub-6 GHz systems, the developed methods do not translate well to mmWave. This turns us to a method called beamforming cancellation (BFC), where the highly directional mmWave beams are steered to mitigate self-interference (SI) and enable simultaneous transmission and reception in-band. In this paper, we present BFC designs for two fully-connected hybrid beamforming scenarios, both of which sufficiently suppress the SI such that the sum spectral efficiency approaches that of a SI-free FD system. A simulation and its results are then used to verify our designs.