Interference Mitigation for Non-Overlapping Sub-Band Full Duplex for 5G-Advanced Wireless Networks

Abstract

With new services emerging in fifth generation (5G)-advanced, the evolution in duplex modes plays an important role to meet more stringent requirements for both downlink (DL) and uplink (UL) transmissions. In this paper, sub-band full duplex (SBFD) at base station (BS) is studied as an attainable evolution of the traditional time division duplex (TDD). Both user equipment (UE) transparent SBFD and UE perceptive SBFD are proposed and studied to serve different types of UEs. To tackle the interference introduced by SBFD, a model including both BS self-interference and cross-link interference (CLI) is presented as a first step, and new interference management schemes are proposed. Three approaches to mitigate BS self-interference, namely the passive suppression, analog interference cancellation and digital interference cancellation are analyzed. A new framework for CLI management is illustrated along with enhancements for interference identification, spatial domain interference coordination and power domain adjustment. To validate the feasibility and performance of the proposed SBFD methods under indoor and dense urban scenarios, system-level simulations (SLSs) are carried out and a proof-of-concept (PoC) is developed for the purpose of obtaining experimental results.

From 5G-Advanced to 6G in 2030: New Services, 3GPP Advances, and Enabling Technologies

“…Furthermore, novel duplexing configurations can be adopted, such as Sub-Band Full Duplex (SBFD). Part of the bands in TDD can be assigned to UEs requiring high uplink throughput, while the rest can be left to downlink heavy traffic by the base station, enabling simultaneous transmission in both directions according to the traffic requirements in the cell [117].…”

The quantum internet: A synergy of quantum information technologies and 6G networks

“…6G is likely to be a three-dimensional (3D) network comprising terrestrial networks, low-earth satellite networks, drones, and high-altitude platform-based networks along with underwater communication networks [50][51][52]. There are also other promising technologies for 6G networks, such as the reconfigurable intelligent surfaces [53,54] and full duplex [55]. Therefore, QKD systems that can operate in a 3D network and compatible with other candidate technologies [56,57] are required for providing quantum security to future networks.…”

Inter-User Interference Cancellation Scheme for 5G-Based Dynamic Full-Duplex Cellular System

“…As we move toward the evolution beyond 5G system (5G-Advanced), a spectrum of new technologies, such as sidelink user equipment (UE)-to-UE relay [3], artificial intelligence/machine learning [4], and sub-band non-overlapping full-duplex (SBFD) [5] have been developed within the third-generation partnership project (3GPP) as part of Release 18 [6], [7]. SBFD enables concurrent uplink (UL) and downlink (DL) communication within a shared carrier while judiciously allocating distinct frequency resources to UL and DL communications to prevent interference.…”

“…SBFD enables concurrent uplink (UL) and downlink (DL) communication within a shared carrier while judiciously allocating distinct frequency resources to UL and DL communications to prevent interference. SBFD has been verified to improve UL throughput and latency by increasing UL transmission opportunities [5]. However, the DL throughput and latency deteriorate because SBFD does not inherently improve spectral efficiency.…”

“…However, the DL throughput and latency deteriorate because SBFD does not inherently improve spectral efficiency. SBFD is recognized as an intermediate step, paving the way for the integration of an in-band fullduplex (IBFD) in the 5G-Advanced evolution or the forthcoming 6th generation mobile communication (6G) system [5], [8]. Hence, the ongoing development of IBFD and SBFD remains imperative.…”