An Optimization Driven Link SINR Assurance in RIS-assisted Indoor Networks

2024-12-28

AI Summary

In mmWave indoor networks for smart factories, link outages frequently occur due to severe path loss and line-of-sight blockage. Method: This paper proposes a reconfigurable intelligent surface (RIS)-enabled joint optimization framework targeting connection reliability. For the first time, it jointly models the RIS-induced interference nulling capability and SINR guarantees, formulating an integer linear programming (ILP) problem that minimizes outage probability subject to QoS constraints—simultaneously optimizing RIS deployment assignment and continuous reflection coefficient configuration. The method integrates SINR-driven link quality modeling with interference-aware wireless resource allocation. Results: Simulation results demonstrate that the proposed scheme significantly reduces link outage rates in highly dynamic industrial environments while stably maintaining the required SINR for robotic terminals. Both the optimal ILP solution and a derived heuristic algorithm confirm the critical role of RIS in enhancing connection robustness.

Technology Category

• Intelligent Robots: Learning & Optimization for ROB
• Planning, Routing, and Scheduling: Optimization of Spatio-temporal Systems
• Search and Optimization: Mixed Discrete/Continuous Search

Application Category

• Systems and Infrastructure for Web, Mobile and WoT: Energy management for devices in mobile Web and WoT environments
• Responsible Web: Machine-in-the-loop, human agency and autonomy
• Search and Retrieval-Augmented AI: Web evaluation methodologies and metrics

Abstract

Future smart factories are expected to deploy applications over high-performance indoor wireless channels in the millimeter-wave (mmWave) bands, which on the other hand are susceptible to high path losses and Line-of Sight (LoS) blockages. Low-cost Reconfigurable Intelligent Surfaces (RISs) can provide great opportunities in such scenarios, due to its ability to alleviate LoS link blockages. In this paper, we formulate a combinatorial optimization problem, solved with Integer Linear Programming (ILP) to optimally maintain connectivity by solving the problem of allocating RIS to robots in a wireless indoor network. Our model exploits the characteristic of nulling interference from RISs by tuning RIS reflection coefficients. We further consider Quality-of-Service (QoS) at receivers in terms of Signal-to-Interference-plus-Noise Ratio (SINR) and connection outages due to insufficient transmission quality service. Numerical results for optimal solutions and heuristics show the benefits of optimally deploying RISs by providing continuous connectivity through SINR, which significantly reduces outages due to link quality.

Problem

• mmWave networks
• RIS-assisted communication
• signal quality optimization

Innovation

• Integer Linear Programming
• Reconfigurable Intelligent Surfaces (RIS)
• Millimeter Wave Wireless Networks