Ray Tracing Based Channel Modeling For RIS Empowered Indoor Wireless Communication Scenarios

Wireless communication technology provides the last kilometer of communication voice and network access services,providing great convenience for people’s life.Due to the complexity of wireless communication scenarios,wireless communication has been committed to improving wireless signals’ coverage and quality.Some data show that indoor wireless data traffic and services account for more than 70%of the total wireless data traffic.The characteristics of radio wave propagation in indoor scenes will affect the performance of indoor wireless communication technology,so it is of great significance to research on indoor wireless channels.RIS(Reconfigurable Intelligent Surface)is a new technology that changes the communication environment and provides new possibilities for improving the coverage and quality of signals.It is necessary to explore the influence of RIS on the wireless channel.The wireless channel is an integral part of a wireless communication system.The wireless channel model is often used to simulate wireless channels and provide a benchmark for performance evaluation of wireless communication technology and systems.The ray tracing technique uses geometrical optics and continuous diffraction theory to predict the propagation path of electromagnetic waves.In this paper,channel characteristic analysis and modeling for wireless channels in several typical indoor scenarios are based on ray-tracing simulations.The main work and innovation are as follows:(1)The channel characteristics and modeling without RIS are studied for several typical indoor environments.Three specific indoor scenarios(office,meeting room,and laboratory)were built using ray-tracing simulation tool,and 28 GHz channel data were obtained.We built a 3D model for the office building and obtained 2.4Ghz channel data.In order to simulate the coverage of a large area of the public space in the building,channel analysis was carried out to obtain various statistical parameters needed for modeling,including power delay spectrum,path loss,shadow fading,and other large-scale parameters.The correlation coefficient and correlation distance of the cumulative distribution function were studied by fitting and merging.(2)Channel characteristics and channel modeling of the above indoor scene under RIS enabling conditions are studied.A new simulation method for integrating RIS into the commercial ray tracing engine is proposed,and the channel is divided into Tx-RIS and RIS-Rx to analyze the channel characteristic parameters separately.RIS is taken as a receiving MIMO antenna and a transmitting MIMO antenna,respectively.When integrating the RIS panel,the channel characteristics are analyzed by combining the RIS’s elemental radiation model to form a cascade channel.The channel characteristics such as shadow fading,delay,and angle spreads are analyzed.It is proven that the RIS panel can enhance signal coverage.The influence of the RIS reflection matrix on channel characteristics such as power delay spectrum and channel capacity under different conditions is analyzed.