Timing Offset Determination for Inter-Frequency OTDOA Measurements

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

In wireless communication networks, determining timing information for cells, especially when a UE has an unsynchronized serving cell or when assistance data does not convey the timing of the reference cell relative to the serving cell, poses challenges in providing measurement gaps for inter-frequency OTDOA measurements.

Innovation Solution

A method where a UE determines the timing offset between a reference cell and a serving cell by using intermediate cell timing offsets, allowing the serving cell to calculate a measurement gap pattern for the UE based on these offsets, enabling the UE to perform inter-frequency OTDOA measurements.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If a UE has an unsynchronized serving cell or assistance data does not convey timing of reference cell relative to serving cell, then the UE cannot determine measurement gaps for inter-frequency OTDOA measurements, but this creates a problem in providing accurate timing information for positioning

Engineering Contradiction:
Improvetiming information accuracyVSAvoidtiming determination complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent introduces an intermediate cell as a mediator between the reference cell and serving cell. The UE first determines timing offset between the intermediate cell and serving cell, then uses this as a reference to determine timing offset between reference cell and serving cell. This intermediary approach breaks down the complex direct timing determination into manageable steps, resolving the contradiction between measurement precision and device complexity.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If the UE uses intermediate cell timing offsets to determine reference cell timing, then measurement gaps can be accurately determined, but the procedure becomes more complex

Engineering Contradiction:
Improvemeasurement gap determination reliabilityVSAvoidtiming determination procedure simplicity
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The patent segments the timing determination procedure into distinct steps: first determining timing offset between intermediate cell and serving cell, then determining timing offset between reference cell and intermediate cell, and finally combining these to get timing offset between reference cell and serving cell. This segmentation makes the complex procedure more manageable and reliable, addressing the contradiction between reliability and ease of operation.

Inventive Principle:
Principle #1Segmentation

3Adaptability or versatility

If the serving cell is unsynchronized, then the network flexibility is improved, but the UE cannot perform inter-frequency OTDOA measurements without measurement gaps

Engineering Contradiction:
Improvenetwork synchronization flexibilityVSAvoidOTDOA measurement capability
Core Design Contradiction:
Adaptability or versatilityVSMeasurement precision

Solution Approach 1:

The patent applies preliminary action by having the UE determine the timing offset between the reference cell and serving cell before performing inter-frequency OTDOA measurements. This advance timing determination enables the UE to know when measurement gaps will occur, allowing the serving cell to be unsynchronized while still enabling precise OTDOA measurements. The preliminary timing information resolves the contradiction between network flexibility and measurement capability.

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentEP2757841B1Method and apparatus for determining timing information for cells
Publication Date: 2021.03.17 QUALCOMM INC
  • EP2757841B1 patent drawingFigure 1
  • EP2757841B1 patent drawingFigure 2
  • EP2757841B1 patent drawingFigure 3

AI summary

Techniques for determining timing information for cells are disclosed. A user equipment (UE) may communicate with a serving cell and may need to make measurements of other cells, e.g., to support positioning of the UE. Each cell may transmit reference signals based on its timing. Different cells may operate asynchronously or with unknown timing. The UE may send a request for measurement gaps to the serving cell and may include timing information in the request. The timing information may (directly or indirectly) convey relative timing between the serving cell and a reference cell. The serving cell may determine measurement gaps at the proper time for other cells based on the timing information from the UE and may avoid scheduling the UE for data transmission during the measurement gaps.; The UE may make measurements of other cells during the measurement gaps, without losing any data from the serving cell.