5G Synchronization Block Timing Determination via PBCH Merge

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

In 5G wireless communication, user equipment (UE) faces challenges in determining the specific time slot and sub-frame for transmitting synchronization blocks within a 20 ms period without increasing decoding complexity or wasting limited PBCH resources.

Innovation Solution

The method involves descrambling and decoding PBCH messages to buffer symbol data, merging it with adjacent beam data, and using explicit and implicit bits to determine the timing index and system frame number, reducing descrambling complexity while effectively indicating the synchronization block's timing and frame number.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of information

If the UE obtains synchronization timing information through PBCH message, then the timing index and system frame number can be indicated, but the PBCH resource is limited and decoding complexity increases

Engineering Contradiction:
Improvetiming index informationVSAvoiddecoding complexity
Core Design Contradiction:
Loss of informationVSDevice complexity

Solution Approach 1:

The 20 ms synchronization block set period is divided into multiple 5 ms windows, with each window containing multiple synchronization blocks. The timing index is segmented into a window index (indicating which 5 ms window) and a sub-frame index (indicating position within the window). This segmentation allows the UE to determine timing information without requiring the entire 20 ms period to be encoded in a single PBCH message, reducing decoding complexity while preserving complete timing information.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent introduces a time dimension by organizing synchronization blocks into a hierarchical structure: 20 ms period → 5 ms windows → sub-frames → synchronization blocks. The window index operates in one dimension (which 5 ms window), while the sub-frame index operates in another dimension (position within the window). This multi-dimensional approach efficiently packs timing information into the limited PBCH resource without increasing decoding complexity.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Loss of time

If all synchronization blocks in a 20 ms period are sent within 5 ms, then the transmission deadline is met, but the timing precision for identifying specific slots and sub-frames is lost

Engineering Contradiction:
Improvetransmission timing accuracyVSAvoidtime index information
Core Design Contradiction:
Loss of timeVSLoss of information

Solution Approach 1:

The timing index is segmented into two parts: a window index indicating which 5 ms window (out of four possible windows in 20 ms) contains the synchronization block, and a sub-frame index indicating the specific sub-frame position within that window. This segmentation allows precise identification of transmission timing even when multiple synchronization blocks are compressed into a 5 ms window, as each block can be uniquely identified by its window index and sub-frame index pair.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The UE performs preliminary determination of the window index based on the received synchronization block's position within the 5 ms window. This preliminary action allows the UE to narrow down the search space and determine the specific time slot and sub-frame without requiring complex decoding of the entire 20 ms period, thereby maintaining timing precision while meeting the 5 ms transmission deadline.

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentEP3641416B1Method and user equipment for determining time of transmitting synchronization block
Publication Date: 2024.10.16 BEIJING XIAOMI MOBILE SOFTWARE CO LTD
  • EP3641416B1 patent drawingFigure 1A~1B
  • EP3641416B1 patent drawingFigure 1C~1D
  • EP3641416B1 patent drawingFigure 1E~2A

AI summary

The present disclosure relates to a method and a device for determining the time for transmitting a synchronization block, user equipment, and a base station. The methods comprises: performing descrambling and decoding processing on a physical broadcast channel (PBCH) message carried in a synchronous block, buffering PBCH symbol data of the PBCH message; after successful descrambling and failed decoding, acquiring PBCH symbol data to be merged, which is the same as the buffered PBCH symbol data, the PBCH symbol data to be merged comprising PBCH symbol data of a beam which is the same as the beam where the synchronous block is located and PBCH symbol data of an adjacent beam in a PBCH merge period; and merging the buffered PBCH symbol data with the PBCH symbol data to be merged. The technical solution of the present disclosure may effectively indicate, in a 5G system, the time of transmitting a synchronous block and the system frame number, and merge PBCH symbol data without increasing the complexity of a UE.