# RIS Wireless Network Optimization Based on TD3 Algorithm in Coal-Mine Tunnels

## TL;DR

This paper proposes an improved AI algorithm to optimize wireless communication in coal-mine tunnels using reconfigurable intelligent surfaces.

## Contribution

A novel TD3-NF algorithm is introduced for RIS-based communication optimization in coal-mine tunnels.

## Key findings

- The TD3-NF algorithm improves the system's average link rate by 29.07% compared to DDPG.
- An 8 × 8 RIS structure achieves a 3.3 bps/Hz higher average sum rate than a 4 × 4 structure.
- The system reaches 11.1 bps/Hz at 38 dBm transmit power.

## Abstract

As an emerging technology, Reconfigurable Intelligent Surfaces (RIS) offers an efficient communication performance optimization solution for the complex and spatially constrained environment of coal mines by effectively controlling signal-propagation paths. This study investigates the channel attenuation characteristics of a semi-circular arch coal-mine tunnel with a dual RIS reflection link. By jointly optimizing the base-station beamforming matrix and the RIS phase-shift matrix, an improved Twin Delayed Deep Deterministic Policy Gradient (TD3)-based algorithm with a Noise Fading (TD3-NF) propagation optimization scheme is proposed, effectively improving the sum rate of the coal-mine wireless communication system. Simulation results show that when the transmit power is 38 dBm, the average link rate of the system reaches 11.1 bps/Hz, representing a 29.07% improvement compared to Deep Deterministic Policy Gradient (DDPG). The average sum rate of the 8 × 8 structure RIS is 3.3 bps/Hz higher than that of the 4 × 4 structure. The research findings provide new solutions for optimizing mine communication quality and applying artificial intelligence technology in complex environments.