RIS and Repeater SSB Transmission for Initial Access

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Solution Overview

Problem

Existing wireless communication systems face challenges in efficiently utilizing reconfigurable intelligent surfaces (RIS) and repeaters for synchronization signal block (SSB) transmission and initial access, particularly in enhancing coverage and reducing interference in heterogeneous networks.

Innovation Solution

Implementing RIS or repeater-assisted techniques for SSB transmission, including the use of modulation signatures and power control for SSBs, to optimize initial access and improve communication efficiency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Area of stationary object

If RIS or repeater assisted SSB transmission is implemented, then communication coverage is enhanced, but device complexity increases

Engineering Contradiction:
Improvecommunication coverage areaVSAvoidsystem complexity
Core Design Contradiction:
Area of stationary objectVSDevice complexity

Solution Approach 1:

The patent introduces RIS and repeaters as intermediary devices between the base station and user equipment. These intermediaries receive, process, and retransmit SSB signals to extend coverage to areas that would otherwise be unreachable, directly resolving the contradiction by adding intermediate components rather than increasing the complexity of existing devices

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent segments the SSB transmission function into multiple independent components: base station SSB generation, RIS signal processing, repeater amplification, and UE reception. Each component operates independently with simplified functionality, allowing the system to achieve extended coverage without requiring any single device to become overly complex

Inventive Principle:
Principle #1Segmentation

2Reliability

If RIS or repeater assisted SSB transmission is implemented, then network performance is improved, but interference increases

Engineering Contradiction:
Improvenetwork performanceVSAvoidinterference
Core Design Contradiction:
ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The patent applies local quality by configuring RIS elements to provide spatially selective signal enhancement. Different RIS elements can be independently controlled to redirect signals toward specific target areas while maintaining low gain in other directions, thereby improving network performance in coverage holes while minimizing interference generation in other spatial regions

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The patent implements feedback mechanisms where the base station receives measurement reports from UEs about received signal quality and interference levels. Based on this feedback, the base station dynamically adjusts RIS configuration and repeater power levels to optimize network performance while keeping interference below harmful thresholds

Inventive Principle:
Principle #23Feedback

3Productivity

If modulation signatures are used for RIS or repeater identification, then initial access efficiency is improved, but processing complexity increases

Engineering Contradiction:
Improveinitial access efficiencyVSAvoidprocessing complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The patent uses modulation signatures as distinctive 'colors' or identifiers for different RIS and repeater units. Each RIS/repeater is assigned a unique modulation pattern that allows UEs to quickly identify and distinguish between multiple intermediaries during initial access, improving efficiency without requiring complex processing - the UE simply detects which modulation pattern is present to determine which RIS/repeater is transmitting

Inventive Principle:
Principle #32Color changes

Data Source

PatentEP4402828B1Reconfigurable intelligent surface or repeater assisted synchronization signal block transmission and initial access
Publication Date: 2025.10.15 QUALCOMM INC
  • EP4402828B1 patent drawingFigure 1
  • EP4402828B1 patent drawingFigure 2
  • EP4402828B1 patent drawingFigure 3

AI summary

Various aspects of the present disclosure generally relate to wireless communication. In some aspects, a user equipment (UE) may receive a synchronization signal block (SSB) transmitted by a base station. The UE may receive system information that includes reconfigurable intelligent surface (RIS) or repeater assisted initial access information that identifies a set of SSBs that are associated with an RIS or a repeater and a modulation signature associated with the RIS or the repeater. The UE may selectively perform initial access using the SSB or search for another SSB based at least in part on the RIS or repeater assisted initial access information. Numerous other aspects are described.