Analysis of Optimal Bandwidth Partitioning Ratio in Full-Duplex Integrated Access and Backhaul

Integrated access and backhaul (IAB) was introduced by the 3rd Generation Partnership Project (3GPP) to reduce the cost of backhaul links (BL) and construct networks that are more flexible than existing networks by replacing fiber BL with wireless BL. In this paper, we highlight enhancements of resource duplexing in IAB. In the IAB of Release 16, 3GPP supported half-duplex IAB, whereas in Release 17, 3GPP is considering full-duplex (FD) IAB. In FD IAB, the sum of the system's bandwidth (BW) is fixed, and we can partition the BW into each channel. In this paper, we focus on the frequency-division multiplexing FD IAB system proposed by previous research, where the IAB nodes do not experience self-interference. To clarify the system's performance potential, the cross-link interference and concrete wireless nature are not taken into account in this study. We analyze the optimal BW partitioning ratio to maximize the system's spectral efficiency. Our results show that the ratio is dependent on channel conditions, for example, the signal-tonoise ratio and the minimum rate guarantee of user equipments according to a certain rule.