Dynamic Uplink Resource Muting for Cross-Link Interference Estimation

Abstract

Sub-band full duplex (SBFD) operation, which enables simultaneous uplink (UL) and downlink (DL) transmissions over adjacent subbands, has been introduced as a promising duplexing technique for 6G and beyond. However, SBFD introduces cross-link interference (CLI), particularly between neighboring base stations (gNB-to-gNB), which can severely degrade uplink performance. Uniform UL resource muting algorithms have been proposed in the literature to make accurate CLI measurements for the effectiveness of gNB-to-gNB interference mitigation mechanisms. In this paper, we propose an adaptive and non-uniform UL resource muting scheme that dynamically adjusts the number and position of muted resource elements (REs) based on the estimated large-scale interference power distribution. Furthermore, we introduce a frequency-shaped adjacent channel leakage ratio (ACLR) model to reflect realistic leakage behavior in SBFD networks. Simulation results show that non-uniform muting pattern (NuMP) outperforms uniform muting pattern (UMP) in terms of estimation performance, while also requiring fewer muted resource elements, as demonstrated by lower normalized mean square error (NMSE) values and reduced muting overhead.