Flexible Duplexing with Phased Array Antennas for Interference-Aware Multi-User Networks

This letter investigates flexible duplexing (FlexD) for interference-aware multi-user networks employing uniform planar array (UPA)-based directional beam steering. Unlike half-duplex (HD), full-duplex (FD) systems, FlexD adaptively selects the transmission direction based on link quality to enhance interference resilience. We extend FlexD to phased-arrays with location-based beam steering and joint user selection, deriving analytical expressions for throughput outage under fading. A practical direction selection algorithm with partial channel state information (CSI) is developed to reduce overhead. Simulations validate analysis and demonstrate FlexD’s performance over HD and FD under throughput, energy efficiency, and asymmetric traffic, highlighting its potential for next-generation wireless networks.