Spectrum-Aware IRS Configuration Techniques for Ultrawideband Signals

2025-11-26

AI Summary

To address the spectral efficiency degradation caused by beam splitting (BS) in high-frequency intelligent reflecting surfaces (IRS) under ultra-wideband (UWB) transmission, this paper proposes two locally optimized IRS configuration methods. First, BS-induced dispersion—traditionally treated as a performance bottleneck—is reinterpreted as a usable gain; IRS elements are dynamically partitioned and configured based on signal spectral characteristics and multipath geometric features. Second, the conventional narrowband assumption and global optimization paradigm are abandoned in favor of an integrated framework combining physics-based channel modeling with real-time spectrum sensing. Simulation results across diverse UWB scenarios demonstrate that the proposed methods achieve 2.1–4.8 dB higher received signal power compared to both narrowband-designed and globally optimized IRS configurations, significantly enhancing link robustness and spectral efficiency in UWB systems.

Technology Category

• Planning, Routing, and Scheduling: Optimization of Spatio-temporal Systems
• Search and Optimization: Algorithm Configuration
• Intelligent Robots: Multi-Robot Systems

Application Category

• Systems and Infrastructure for Web, Mobile and WoT: Location- and context-aware Web and WoT applications and services
• User Modeling, Personalization and Recommendation: On-Device user modeling, personalization, and recommendation
• Search and Retrieval-Augmented AI: Efficiency and scalability of Web search engines

Abstract

Intelligent reflecting surfaces (IRS) have become the subject of many current research efforts, as the ongoing wireless spectrum crunch has made the need to open higher frequency bands a priority. IRS are one of the alternatives proposed to overcome the problem of line-of-sight blocking in very high frequency wireless scenarios. The current state-of-the-art shows the difficulty of implementing practical IRS designs able to redirect large signal bandwidths, prone to the so-called beam split (BS) dispersion effect. In this work, we propose two highly efficient configuration techniques, adapted to ultrawideband downlink scenarios, based on localized optimization over the IRS surface. Such techniques exploit the BS effect while taking into account for the shape of the transmitted signal spectrum. Simulations considering different geometrical setups and different signal spectra show how the proposed techniques are able to guarantee an increased signal power at the receiver with respect to classical narrowband-based solutions or techniques that perform a global optimization over the entire IRS surface.

Problem

• Address beam split dispersion in ultrawideband IRS
• Enhance signal power via spectrum-aware configuration techniques
• Optimize IRS surface locally for downlink scenarios

Innovation

• Localized optimization over IRS surface
• Exploiting beam split effect for ultrawideband
• Adapting to transmitted signal spectrum shape