Round Trip Time Measurement for Wireless Positioning

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Solution Overview

Problem

Existing positioning methods in wireless communication systems face challenges in generating unique radio fingerprints without excessive radio resource usage, leading to increased system load and decreased capacity.

Innovation Solution

A method and arrangement that utilize round trip time measurements between a base station and user equipment to generate unique radio fingerprints, with periodic reporting based on position change, speed, or Discontinuous Reception cycle, reducing signaling overhead.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If extensive surveying and extra parameter measurements are performed to create unique radio fingerprints, then positioning accuracy is improved, but system load increases and capacity decreases

Engineering Contradiction:
Improvepositioning accuracyVSAvoidsystem capacity
Core Design Contradiction:
Measurement precisionVSProductivity

Solution Approach 1:

The patent extracts only the essential parameter (round trip time) needed for positioning from the set of all possible measurement parameters. Instead of performing extensive surveying with multiple parameters, the system selectively measures only RTT, which significantly reduces measurement overhead while maintaining positioning capability. This extraction principle resolves the contradiction by taking out the harmful excessive measurements while preserving the useful positioning function.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent applies partial action by performing only the necessary RTT measurements rather than complete extensive surveying. The system measures RTT periodically and event-triggered rather than continuously surveying all parameters, achieving positioning accuracy with reduced measurement effort. This partial approach maintains sufficient positioning capability while avoiding the excessive action that would overload the system.

Inventive Principle:
Principle #16Partial or excessive action

2Measurement precision

If extensive surveying and extra parameter measurements are performed to create unique radio fingerprints, then positioning accuracy is improved, but signaling overhead increases

Engineering Contradiction:
Improvepositioning accuracyVSAvoidsignaling overhead
Core Design Contradiction:
Measurement precisionVSLoss of information

Solution Approach 1:

The patent extracts only the critical RTT parameter for positioning, eliminating the need to signal extensive surveying data. By taking out only the essential RTT measurement information rather than all possible parameters, the system maintains positioning accuracy while dramatically reducing signaling overhead. This extraction resolves the contradiction between measurement precision and information loss.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent employs partial action in signaling by reporting only necessary RTT information rather than complete surveying datasets. The system uses event-triggered reporting that sends updates only when positioning-relevant changes occur, avoiding excessive signaling while preserving positioning accuracy. This partial signaling approach balances the contradiction between maintaining precision and reducing overhead.

Inventive Principle:
Principle #16Partial or excessive action

3Reliability

If round trip time measurements are performed periodically or event-triggered, then positioning capability is maintained, but system resources are consumed

Engineering Contradiction:
Improvepositioning capabilityVSAvoidsystem resource consumption
Core Design Contradiction:
ReliabilityVSUse of energy by moving object

Solution Approach 1:

The patent applies dynamics by making the RTT measurement frequency adaptive rather than static. The system transitions between periodic and event-triggered measurement modes based on system conditions, allowing flexible resource consumption that maintains positioning reliability. This dynamic approach resolves the contradiction by adjusting measurement activity to match actual positioning needs, reducing unnecessary resource consumption while preserving capability.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent uses periodic RTT measurements combined with event-triggered updates to maintain positioning capability efficiently. Instead of continuous measurements, the system performs measurements at regular intervals and additional times when events indicate positioning relevance. This periodic action with event supplementation maintains reliability while significantly reducing resource consumption compared to continuous monitoring.

Inventive Principle:
Principle #19Periodic action

Data Source

PatentEP2272275B1Method for determining the round trip time
Publication Date: 2016.06.08 TELEFONAKTIEBOLAGET LM ERICSSON (PUBL)
  • EP2272275B1 patent drawingFigure 1
  • EP2272275B1 patent drawingFigure 2
  • EP2272275B1 patent drawingFigure 3

AI summary

Method and arrangement in a first node for determining the round trip time of a signal. The signal is sent between the first node and a second node. The second node is associated with a location point. The first node and the second node are comprised within a wireless communication system. A first signal is sent to the second node. A second signal is thereafter received by the first node from the second node, where the second signal is sent from the second node as a response to the previously sent first signal. When the second signal is received from the second node, the round trip time of the signal is computed in the first node.The computed round trip time is then sent to the second node. A corresponding method and arrangement in a second node for obtaining the round trip time of a signal is also provided.