Spectral Efficiency Analysis and Optimization in Hybrid RIS Systems Under Nonlinear Power Amplifier Effects

Spectral Efficiency Analysis and Optimization in Hybrid RIS Systems Under Nonlinear Power Amplifier Effects | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Research Article Spectral Efficiency Analysis and Optimization in Hybrid RIS Systems Under Nonlinear Power Amplifier Effects Brahim ELMAROUD This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-6541452/v1 This work is licensed under a CC BY 4.0 License Status: Published Journal Publication published 28 Oct, 2025 Read the published version in Wireless Personal Communications → Version 1 posted 15 You are reading this latest preprint version Abstract This paper investigates the impact of nonlinear distortions caused by high-power amplifiers (HPAs) in hybrid reconfigurable intelligent surface (RIS)-assisted communication systems. By applying the Bussgang theorem, we derive an analytical model for the nonlinear distortions and develop the corresponding expressions for the received signal and the spectral efficiency (SE) in both ideal (linear) and practical (nonlinear) cases, as well as in the passive RIS scenario. To mitigate the performance degradation induced by hardware impairments, we propose an active element selection strategy that aims to optimize the SE by appropriately selecting the active elements of the RIS. Different optimization algorithms are considered, namely a Genetic Algorithm (GA), a Greedy Algorithm, and Random Search (RS). Numerical results highlight the severe impact of nonlinearities on SE and demonstrate that the proposed selection strategy can significantly improve the system performance. Furthermore, we show that the Random Search method provides a favorable trade-off between performance and computational complexity, especially when the number of tested combinations is properly chosen. Reconfigurable Intelligent Surfaces RIS Hybrid RIS OFDM Spectral Efficiency Nonlinear Distortions Optimization Full Text Additional Declarations No competing interests reported. Cite Share Download PDF Status: Published Journal Publication published 28 Oct, 2025 Read the published version in Wireless Personal Communications → Version 1 posted Editorial decision: Revision requested 18 Jul, 2025 Reviews received at journal 14 Jun, 2025 Reviews received at journal 11 Jun, 2025 Reviews received at journal 23 May, 2025 Reviewers agreed at journal 05 May, 2025 Reviews received at journal 04 May, 2025 Reviewers agreed at journal 03 May, 2025 Reviewers agreed at journal 02 May, 2025 Reviewers agreed at journal 01 May, 2025 Reviewers agreed at journal 30 Apr, 2025 Reviewers agreed at journal 30 Apr, 2025 Reviewers invited by journal 30 Apr, 2025 Editor assigned by journal 29 Apr, 2025 Submission checks completed at journal 29 Apr, 2025 First submitted to journal 27 Apr, 2025 You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. 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