UE-Based OTDOA Positioning Accuracy via Beam Direction Data

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Solution Overview

Problem

The existing UE-based DL-TDOA positioning method in wireless communication technology suffers from low positioning accuracy due to the lack of information about downlink positioning reference signal beams in the messages exchanged among the UE, LMF entity, and BS, which hinders accurate UE positioning.

Innovation Solution

The proposed solution involves sending positioning assistance data requests from the terminal to the LMF entity, which includes first identification information of detected beam reference signals, and receiving beam direction information for both serving and neighboring base stations, allowing the terminal to determine Reference Signal Time Difference (RSTD) measurements and improve positioning accuracy using this information.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If the UE-based DL-TDOA positioning method uses only basic cell information (physical cell ID, antenna position, PRS configuration) for positioning, then the positioning process is simple, but the positioning accuracy is reduced due to inability to search for accurate downlink positioning reference signals in multi-beam 5G NR systems

Engineering Contradiction:
Improvepositioning accuracyVSAvoidpositioning assistance data complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent applies preliminary action by having the network side (LMF entity) pre-calculate and provide beam direction information for multiple beams in the positioning assistance data before the UE performs positioning measurement. This allows the UE to efficiently search for the correct downlink positioning reference signal among multiple beams without having to perform complex beam sweeping itself, thereby improving positioning accuracy while controlling complexity.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent introduces beam direction information as an intermediary element that bridges the gap between the basic cell information and the actual downlink positioning reference signal. This intermediary data helps the UE identify which beam contains the positioning signal, resolving the contradiction by adding a targeted information layer without requiring full complexity of beam management.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If the system transmits multiple signal beams (SSBs) in different directions to support 5G NR positioning, then the coverage and signal quality are improved, but the positioning accuracy is reduced when the UE cannot identify the correct beam among multiple beams

Engineering Contradiction:
Improvesignal qualityVSAvoidpositioning accuracy
Core Design Contradiction:
ReliabilityVSMeasurement precision

Solution Approach 1:

The patent applies local quality by providing differentiated information for different beams - specifically, beam direction information is included in the positioning assistance data for each beam. This allows the UE to identify which specific beam (local) contains the positioning signal, rather than treating all beams uniformly. The beam direction information acts as a local identifier that improves positioning accuracy while maintaining the multi-beam signal quality benefits.

Inventive Principle:
Principle #3Local quality

3Difficulty of detecting and measuring

If the UE performs beam sweeping to search for downlink positioning reference signals among multiple beams, then the signal detection capability is improved, but the positioning accuracy is reduced due to the complexity and time consumption of beam search

Engineering Contradiction:
Improvesignal detection capabilityVSAvoidpositioning accuracy
Core Design Contradiction:
Difficulty of detecting and measuringVSMeasurement precision

Solution Approach 1:

The patent applies preliminary action by having the network pre-provide beam direction information in the positioning assistance data, which guides the UE's beam search process. Instead of performing exhaustive beam sweeping, the UE can directly search in the indicated beam direction, significantly reducing search time and improving positioning accuracy while maintaining signal detection capability.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent applies partial action by having the network provide beam direction information for a subset of beams that are most likely to contain the positioning signal, rather than requiring the UE to search all possible beams. This partial information provision is sufficient to achieve accurate positioning without the need for complete beam sweeping.

Inventive Principle:
Principle #16Partial or excessive action

Data Source

PatentEP3926357B1Positioning method,terminal and LMF entity
Publication Date: 2024.10.30 DATANG MOBILE COMM EQUIP CO LTD
  • EP3926357B1 patent drawingFigure 1
  • EP3926357B1 patent drawingFigure 2
  • EP3926357B1 patent drawingFigure 3

AI summary

A positioning method, a device, a system, a terminal, an LMF entity, and a medium, used to solve the problem of low positioning accuracy of UE-based OTDOA in the prior art. The method comprises: a terminal sending to a location management function (LMF) entity an auxiliary positioning data request message comprising first identification information of a beam reference signal detected by the terminal itself (S101); receiving from the LMF entity auxiliary positioning data of beam direction information of a beam reference signal comprising second identification information, wherein the second identification information is identification information of a beam reference signal sent by a neighboring base station and determined, according to the first identification information, by the LMF entity as being detectable by the terminal (S102); and determining an RSTD of each beam reference signal having the first identification information or the second identification information, and determining position information of the terminal according to the determined RSTD and abeam direction of each beam reference signal (S 103).