Capacity of Two-User Wireless Systems Aided by Movable Signals

2026-01-29

AI Summary

This study investigates how reconfigurable signals can enhance the capacity region of two-user wireless systems. Focusing on both multiple-access and broadcast channels, the work proposes a novel approach that dynamically adjusts operating frequencies to orthogonalize user channels, thereby introducing reconfigurable signaling into dynamic frequency optimization under bandwidth constraints for the first time. Grounded in information-theoretic capacity analysis and multiuser channel modeling, the proposed method significantly expands the achievable capacity region within limited bandwidth. Compared to conventional schemes employing fixed signaling, it achieves up to a 45% gain in sum rate, demonstrating the substantial performance benefits of adaptive frequency allocation enabled by reconfigurable signal design.

Technology Category

• Planning, Routing, and Scheduling: Optimization of Spatio-temporal Systems
• Search and Optimization: Algorithm Configuration
• Multiagent Systems: Mechanism Design

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: On-Device user modeling, personalization, and recommendation
• Graph Algorithms and Modeling for the Web: Efficient manipulation of static and dynamic Web-related graphs

Abstract

Movable signals have emerged as a third approach to enable smart radio environments (SREs), complementing reconfigurable intelligent surfaces (RISs) and flexible antennas. This paper investigates their potential to enhance multi-user wireless systems. Focusing on two-user systems, we characterize the capacity regions of the multiple access channel (MAC) and broadcast channel (BC). Interestingly, movable signals can dynamically adjust the operating frequency to orthogonalize the user channels, thereby significantly expanding the capacity regions. We also study frequency optimization, constraining it in a limited frequency range, and show that movable signals provide up to 45% sum rate gain over fixed signals.

Problem

• movable signals
• capacity region
• two-user wireless systems
• multiple access channel
• broadcast channel

Innovation

• movable signals
• smart radio environments
• capacity region
• frequency orthogonality
• sum rate gain