Split RIS Control for Low-Overhead Non-Line-of-Sight Coverage
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Solution Overview
Problem
The maximum data rate supported by electronic devices is limited by the frequency of radio-frequency signals, which become subject to significant over-the-air attenuation and require line-of-sight, making it difficult to perform satisfactory wireless communications as software applications become more data-intensive.
Innovation Solution
A communication system utilizing reconfigurable intelligent surfaces (RIS) with antenna elements that reflect wireless signals, where the selection and adjustment of reflection coefficients are split between a remote controller, local controller, and user equipment device, enabling machine learning or artificial intelligence training for optimized control.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If higher frequency radio-frequency signals are used to increase data rates, then data rate is improved, but signal attenuation increases and line-of-sight requirements become more stringent
Solution Approach 1:
A reconfigurable intelligent surface (RIS) is introduced as an intermediary device between the base station and user equipment. The RIS reflects and redirects high-frequency signals around obstacles, enabling non-line-of-sight communication while maintaining signal strength and data rates that would otherwise be lost due to attenuation
2Productivity
If control of RIS reflection coefficients is centralized in a remote controller, then coordination efficiency is improved, but communication overhead increases
Solution Approach 1:
The control function is segmented and distributed across multiple entities: the remote controller handles high-level coordination and model management, while local controllers on individual RIS devices handle real-time reflection coefficient adjustment. This segmentation reduces communication overhead by eliminating the need for continuous centralized control while maintaining coordination efficiency
3Area of stationary object
If more RIS devices are deployed to extend coverage, then coverage area is improved, but system complexity increases
Solution Approach 1:
Each RIS device is equipped with a local controller that autonomously manages its own operation and configuration. The local controller receives a control model from the remote controller and independently adjusts reflection coefficients based on local channel conditions, eliminating the need for complex centralized management and reducing overall system complexity while enabling scalable deployment
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
Minimizes communication overhead, provides coverage extension, and optimizes privacy by optimizing the reflection coefficients of RIS, allowing effective wireless communications even in non-line-of-sight conditions.
Implementation Method 1
The RIS may include antenna elements that reflect wireless signals between a base station and a UE device while antenna elements on the RIS are configured to exhibit a set of reflection coefficients
Data Source
AI summary
A communication system may include a base station (BS), a user equipment (UE) device, a reconfigurable intelligent surface (RIS) having a local controller, and a remote controller. Antenna elements on the RIS may reflect signals between the BS and UE while exhibiting reflection coefficients. The remote controller may transmit a control model and the UE may transmit local information to the local controller, which generates the reflection coefficients based on the local information and control model. Alternatively, the remote controller may transmit the control model to the UE and a codebook to the RIS. The UE may transmit an identifier to the RIS based on local information and the control model. The local controller may implement reflection coefficients of a codebook entry identified by the identifier. Splitting control of the RIS in these ways may minimize communication overhead, provide coverage extension for the UE, and optimize privacy.