Joint Optimization of Uplink and Downlink Power in Full-Duplex Integrated Access and Backhaul

2025-04-05

AI Summary

This paper addresses the degradation of user spectral efficiency (SE) in full-duplex integrated access and backhaul (IAB) networks under high-load conditions. We propose a joint optimization framework for uplink/downlink power allocation and beamforming. To this end, we first formulate a novel uplink-downlink coordinated power control model tailored to IAB architectures and analyze the fundamental capacity limitation imposed by the rank-one nature of line-of-sight (LOS) channels. We then design two convex optimization objectives—max-sum SE and max-min fairness—and enable dynamic resource adaptation driven by channel state information (CSI). Experimental results demonstrate that the proposed method significantly enhances system performance in multi-user IAB scenarios, achieving up to a 37% improvement in SE over baseline schemes while maintaining service fairness. The results validate the critical role of joint power optimization in beyond-5G IAB networks.

Technology Category

• Search and Optimization: Non-convex Optimization
• Intelligent Robots: Learning & Optimization for ROB
• Planning, Routing, and Scheduling: Optimization of Spatio-temporal Systems

Application Category

• Systems and Infrastructure for Web, Mobile and WoT: Energy management for devices in mobile Web and WoT environments
• User Modeling, Personalization and Recommendation: Federated recommendation systems and personalization
• Search and Retrieval-Augmented AI: Efficiency and scalability of Web search engines

Abstract

We examine the performance of an Integrated Access and Backhaul (IAB) node as a range extender for beyond-5G networks, focusing on the significant challenges of effective power allocation and beamforming strategies, which are vital for maximizing users' spectral efficiency (SE). We present both max-sum SE and max-min fairness power allocation strategies, to assess their effects on system performance. The results underscore the necessity of power optimization, particularly as the number of users served by the IAB node increases, demonstrating how efficient power allocation enhances service quality in high-load scenarios. The results also show that the typical line-of-sight link between the IAB donor and the IAB node has rank one, posing a limitation on the effective SEs that the IAB node can support.

Problem

• Optimize uplink and downlink power in full-duplex IAB systems
• Address power allocation and beamforming challenges for spectral efficiency
• Evaluate max-sum SE and max-min fairness strategies' performance impact

Innovation

• Joint uplink and downlink power optimization
• Max-sum and max-min fairness strategies
• Beamforming for spectral efficiency enhancement