SSB Bitmap Rate Matching in Unlicensed Spectrum Windows

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Solution Overview

Problem

Existing wireless communication systems face challenges in efficiently managing synchronization signal blocks (SSBs) in unlicensed spectrum due to interference and contention for access, which affects the reliability and efficiency of data transmission.

Innovation Solution

A method involving a UE and a base station that utilize a bitmap to indicate an SSB transmission pattern, allowing for rate matching around candidate SSB positions based on specific parameters, ensuring efficient data transmission by avoiding interference from SSBs.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If rate matching is performed around all candidate SSB positions, then data transmission reliability is improved, but device complexity increases due to the need to process and interpret bitmap information indicating SSB transmission patterns

Engineering Contradiction:
Improvedata transmission reliabilityVSAvoidrate matching processing complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The base station performs preliminary action by transmitting bitmap information that indicates the SSB transmission pattern before the actual data transmission. This bitmap contains advance information about which candidate SSB positions will be used, allowing the UE to pre-configur its rate matching behavior without needing to process complex real-time information during data reception.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The bitmap acts as an intermediary element that carries SSB transmission pattern information from the base station to the UE. Instead of the UE directly analyzing complex SSB scheduling decisions or interference patterns, the bitmap serves as a simplified intermediary indicator that conveys the essential information needed for rate matching, reducing processing complexity while maintaining reliability.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Productivity

If SSB transmission positions are dynamically adjusted to avoid interference, then communication efficiency is improved, but loss of time increases due to uncertainty about actual SSB transmission timing in unlicensed spectrum

Engineering Contradiction:
Improvedata transmission efficiencyVSAvoidtime uncertainty
Core Design Contradiction:
ProductivityVSLoss of time

Solution Approach 1:

The base station transmits the bitmap indicating SSB transmission pattern as preliminary information before the data transmission occurs. This allows the UE to know in advance which time slots will contain SSBs and which will be available for data, enabling the UE to efficiently schedule its reception without experiencing time uncertainty or delays.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The bitmap provides feedback information from the base station about its intended SSB transmission schedule to the UE. This feedback mechanism allows the UE to adjust its reception timing expectations accordingly, resolving the time uncertainty issue by having the base station explicitly communicate its scheduling decisions to the UE before data transmission begins.

Inventive Principle:
Principle #23Feedback

Data Source

PatentEP4062687B1Rate matching around synchronization signal blocks in unlicensed spectrum
Publication Date: 2025.12.31 QUALCOMM INC
  • EP4062687B1 patent drawingFigure 1
  • EP4062687B1 patent drawingFigure 2
  • EP4062687B1 patent drawingFigure 3A

AI summary

Various aspects of the present disclosure generally relate to wireless communication. In some aspects, a base station may transmit, and a user equipment (UE) may receive, a bitmap that includes a bit sequence to indicate a synchronization signal block (SSB) transmission pattern. The UE may perform rate matching around one or more candidate SSB positions in an initial portion of a window in which SSB transmission is expected, based at least in part on the bitmap, a first parameter indicating a quantity of initial candidate SSB positions in the window subject to rate matching, and a second parameter indicating a quantity of initial bits in the bit sequence that define the SSB transmission pattern. Numerous other aspects are provided.