RIS Failure Mitigation via Companion Codebooks
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Reconfigurable intelligent surface (RIS) elements may fail due to aging or environmental variations, leading to uncontrollable phase shifts and destructive combining of signals, which negatively impacts the gain and overall performance of wireless communication systems.
Innovation Solution
The proposed solution involves a network node receiving a configuration of a codebook associated with an RIS pattern and an indication of a codeword potentially associated with RIS element failure. Based on this indication, the network node performs RIS failure mitigation by providing an indication to the RIS controller to use a common phase offset or a codeword from a companion codebook to mitigate the impact of failed elements.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If RIS elements are used to improve wireless communication performance, then signal gain and coverage are improved, but RIS element failures occur due to aging or environmental variations causing uncontrollable phase shifts and destructive combining
Solution Approach 1:
The patent applies preliminary action by performing failure mitigation before actual signal transmission occurs. The network node receives an indication of a codeword potentially associated with RIS element failure and proactively configures a companion codebook or applies phase offset adjustments in advance. This prevents destructive combining from occurring in the first place, rather than reacting after failure is detected
Solution Approach 2:
The patent converts the harmful effect of uncontrollable phase shifts from failed RIS elements into a beneficial outcome. By receiving indications of potentially failed elements and using this information to configure companion codebooks or apply phase offset adjustments, the system transforms the knowledge of failure into a mechanism that eliminates destructive combining and maintains signal gain
2Reliability
If phase offset adjustments are applied to mitigate RIS element failures, then signal gain is maintained, but system complexity increases due to additional control mechanisms
Solution Approach 1:
The patent introduces an intermediary mechanism - the network node - that receives indications of RIS element failures from the RIS controller and coordinates the failure mitigation process. This intermediary manages the complexity by centralizing the decision-making for phase offset adjustments and companion codebook configuration, rather than requiring each RIS element to independently manage its own failure state
Solution Approach 2:
The patent implements feedback by having the RIS controller monitor RIS element status and provide indications of potentially failed elements to the network node. This feedback loop enables the system to dynamically adjust phase offsets and codebook configurations based on actual failure conditions, maintaining reliability while managing complexity through information-based control
Data Source
AI summary
Various aspects of the present disclosure generally relate to wireless communication. In some aspects, a network node may receive, from a network entity, a configuration of a codebook associated with a reconfigurable intelligent surface (RIS) pattern. The network node may receive, from the network entity, an indication of a codeword in the codebook that is potentially associated with RIS element failure based at least in part on one or more RIS attributes. The network node may perform an RIS failure mitigation based at least in part on the indication. Numerous other aspects are described.