Responder UE Collision Detection for Ranging Sessions

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Solution Overview

Problem

In distributed wireless communication systems, multiple user equipment (UEs) may initiate separate ranging sessions simultaneously, leading to collisions in ranging signals due to overlapping sets of participating UEs, which undermines accurate positioning and ranging.

Innovation Solution

A responder UE detects collisions in ranging signals by determining if broadcast times and frequencies are within a predetermined amount of time and sends an indication to the initiator UE, allowing for rescheduling or continuation of ranging sessions to minimize collisions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If multiple ranging sessions are conducted simultaneously in a distributed system, then positioning coverage and service availability are improved, but signal collisions and measurement precision deteriorate

Engineering Contradiction:
Improvepositioning coverageVSAvoidranging accuracy
Core Design Contradiction:
Adaptability or versatilityVSMeasurement precision

Solution Approach 1:

The responder UE performs preliminary collision detection by comparing the requested PRS broadcast time with previously scheduled PRS transmissions before confirming participation in the ranging session. This preliminary action prevents signal collisions by identifying scheduling conflicts in advance, allowing the system to maintain multiple simultaneous ranging sessions without compromising ranging accuracy.

Inventive Principle:
Principle #10Preliminary action

2Measurement precision

If ranging sessions are coordinated to avoid collisions, then measurement precision is improved, but system complexity and device complexity increase

Engineering Contradiction:
Improveranging accuracyVSAvoidsession management complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The responder UE autonomously performs collision detection and notifies initiator UEs of scheduling conflicts without requiring centralized coordination or complex session management infrastructure. Each responder independently manages its own PRS scheduling by comparing requested times with its own transmission schedule, significantly reducing system complexity while maintaining ranging accuracy.

Inventive Principle:
Principle #25Self-service

3Reliability

If collision detection and notification mechanisms are implemented, then signal transmission reliability is improved, but loss of time and processing overhead increase

Engineering Contradiction:
Improvesignal transmission reliabilityVSAvoidsession setup time
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

Collision detection is performed during the ranging session setup phase before actual PRS transmissions begin. By identifying and resolving scheduling conflicts in advance through the pre-ranging message exchange, the system ensures reliable signal transmission without adding significant time overhead during the actual ranging measurement process.

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentEP4295173B1Optimization of ranging sessions initiated by vehicle and pedestrian ues
Publication Date: 2026.03.11 QUALCOMM INC
  • EP4295173B1 patent drawingFigure 1
  • EP4295173B1 patent drawingFigure 2
  • EP4295173B1 patent drawingFigure 3

AI summary

A responder user equipment (UE) in separate ranging sessions may determine whether there is a collision between the ranging signals assigned to broadcast in the separate ranging sessions. A collision in the ranging signals is detected when the ranging signals have the same frequencies and broadcast times, e.g., the broadcast time of one ranging signal is within a predetermined amount of time for the other ranging signal. When a collision in the ranging signals is detected, the responder UE sends a message to the initiator UE indicating the possibility of a collision. Available times for broadcasting the ranging signals may be determined, e.g., by the responder UE or the initiator UE. The initiator UE may initiate a new ranging session based on the available times for broadcasting the ranging signal or may proceed with the ranging session with the possibility that the responder UE will not participate.