RIS Selection Using Path Delay Differences to Limit Signal Blocking

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Solution Overview

Problem

Current technologies lack efficient methods for selecting reconfigurable intelligent surfaces (RIS) in wireless communication networks without detailed channel information, leading to potential communication degradation due to destructive signal superposition and inefficient measurement overhead.

Innovation Solution

A method for selecting RIS based on simple measurements of signals between a base station and user equipment (UE), utilizing slow-varying RIS information, such as capability and geometric data, to determine optimal RISs for communication, considering path delay differences and interference management.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If detailed channel information is used for RIS selection, then communication performance can be optimized, but measurement overhead increases significantly

Engineering Contradiction:

Improvecommunication performanceVSAvoidmeasurement overhead

Core Design Contradiction:

ReliabilityVSLoss of time

Solution Approach 1:

The patent extracts only the essential geometric information (location, orientation, service area) and capability information from the complete channel state information, discarding the detailed channel measurements. This allows RIS selection to be performed using minimal information, significantly reducing measurement overhead while maintaining sufficient performance through path delay difference-based selection criteria.

Inventive Principle:

Principle #2Taking out (Extraction)

2Reliability

If multiple RISs are deployed to improve coverage, then communication reliability increases, but destructive signal superposition may occur causing performance degradation

Engineering Contradiction:

ImprovecoverageVSAvoiddestructive signal superposition

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent applies preliminary anti-action by calculating path delay differences between direct and reflected paths before signal transmission occurs. By selecting RISs whose path delay differences fall within acceptable thresholds, the system preemptively prevents destructive superposition from occurring, ensuring constructive or neutral signal combination rather than allowing harmful interference to develop.

Inventive Principle:

Principle #9Preliminary anti-action

3Loss of time

If simple measurements are used for RIS selection, then measurement overhead is reduced, but selection accuracy may deteriorate

Engineering Contradiction:

Improvemeasurement overheadVSAvoidselection accuracy

Core Design Contradiction:

Loss of timeVSMeasurement precision

Solution Approach 1:

The patent implements preliminary action by pre-calculating and storing path delay differences between direct and reflected communication paths for multiple candidate RISs. This pre-computation allows the system to perform rapid RIS selection based on simple threshold comparisons rather than requiring complex real-time channel measurements, achieving both low overhead and accurate selection through advance preparation of selection criteria.

Inventive Principle:

Principle #10Preliminary action

Data Source

PatentUS20260019108A1Systems, methods, and devices for selection of reconfigurable intelligent surfaces (RIS)

Publication Date: 2026.01.15 APPLE INC

AI summary

The techniques described herein can include solutions for selection of reconfigurable intelligent surfaces (RISs). RIS selection can be performed by a base station and/or a user equipment (UE). RIS selection can be directed to reducing signal degradation, addressing dynamic signal blocking, reducing outage probabilities, interference, and more. RIS selection can include selection of signaling resources, such as channels, bands, and sub-bands.