PBCH Timing Indication via DMRS Segmentation

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Solution Overview

Problem

Current wireless communication systems face challenges in efficiently conveying timing information within transmission time intervals, particularly in New Radio (NR) and 5G technologies, where timing reference numbers change over the duration of a PBCH TTI, requiring innovative methods to maintain consistent content across redundant versions for improved decoding performance.

Innovation Solution

The method involves determining a first set of bits of a timing reference number that change over a PBCH transmission time interval and transmitting multiple versions of the PBCH, with a second set of bits that remain constant, providing an indication of the changing bits with each transmission, allowing for accurate timing information conveyance and decoding.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of information

If timing reference number bits are conveyed in PBCH, then timing information is provided, but content consistency across redundant PBCH versions deteriorates when timing bits change within TTI

Engineering Contradiction:
Improvetiming information conveyanceVSAvoiddecoding performance
Core Design Contradiction:
Loss of informationVSReliability

Solution Approach 1:

The timing reference number bits are segmented into two sets: a first set of bits that change over the duration of the PBCH TTI and are conveyed separately (e.g., through DMRS or other indicators), and a second set of bits that remain constant and are conveyed in the PBCH. This segmentation allows the PBCH content to remain consistent across redundant versions while still providing complete timing information when combined with the separately conveyed first set of bits.

Inventive Principle:
Principle #1Segmentation

2Reliability

If multiple PBCH versions are transmitted within TTI, then redundancy for decoding is improved, but timing information accuracy deteriorates due to content variations

Engineering Contradiction:
Improvedecoding performanceVSAvoidtiming information accuracy
Core Design Contradiction:
ReliabilityVSMeasurement precision

Solution Approach 1:

The changing timing reference number bits (first set) are extracted from the PBCH content and conveyed through separate mechanisms such as DMRS (demodulation reference signals) or other physical layer indicators. The PBCH itself contains only the constant second set of timing bits, ensuring content consistency across all redundant PBCH versions transmitted within the TTI, while the extracted first set of bits provides the time-varying timing information.

Inventive Principle:
Principle #2Taking out (Extraction)

3Loss of time

If timing reference number is conveyed in PBCH, then timing synchronization is enabled, but PBCH content consistency across transmissions deteriorates

Engineering Contradiction:
Improvesynchronization timingVSAvoidPBCH content consistency
Core Design Contradiction:
Loss of timeVSStability of the object's composition

Solution Approach 1:

The timing reference number is segmented into static and dynamic components. The static second set of bits that define the fundamental timing structure are embedded in the PBCH content, which remains consistent across all transmissions. The dynamic first set of bits that vary within the TTI are conveyed separately through DMRS or other physical layer signals, thereby maintaining PBCH content stability while still providing complete timing synchronization information.

Inventive Principle:
Principle #1Segmentation

Data Source

PatentEP3619853B1Timing indication through DMRS/PBCH in different modes
Publication Date: 2021.03.17 QUALCOMM INC
  • EP3619853B1 patent drawingFigure 1
  • EP3619853B1 patent drawingFigure 2
  • EP3619853B1 patent drawingFigure 3

AI summary

Certain aspects of the present disclosure relate to methods and apparatus for conveying timing information that changes across a transmission time interval (TTI) in which multiple redundancy versions of a physical broadcast channel (PBCH) are transmitted.