V2X Terminal HARQ Feedback Based on Distance

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Solution Overview

Problem

Existing HARQ technologies in V2X communication systems face inefficiencies in resource utilization and inaccurate distance calculations, leading to unnecessary data retransmissions and reduced system capacity due to frequent location information exchange and inaccurate reference signal received power calculations.

Innovation Solution

Implement a communication method where terminals send acknowledgment information based on a preset distance range and conditions, such as time duration and block error rates, to optimize data transmission efficiency and accuracy, and correct distance values using relative movement speed adjustments.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If location information is frequently exchanged between vehicles to determine distance, then distance measurement accuracy is improved, but time-frequency resources are consumed and system capacity decreases

Engineering Contradiction:
Improvedistance measurement accuracyVSAvoidsystem capacity
Core Design Contradiction:
Measurement precisionVSProductivity

Solution Approach 1:

The second terminal performs preliminary action by broadcasting both location information and reference signal received power threshold together, eliminating the need for frequent location information exchange while enabling accurate distance determination through the pre-provided reference signal threshold

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The reference signal received power acts as an intermediary parameter to indirectly determine distance without requiring direct location information exchange. The first terminal uses the reference signal received power threshold to judge whether the distance is within the service distance, avoiding frequent location information communication

Inventive Principle:
Principle #24Intermediary (Mediator)

2Productivity

If reference signal received power is used to determine distance, then location information exchange frequency is reduced, but distance measurement accuracy deteriorates due to signal obstruction

Engineering Contradiction:
Improveresource utilization efficiencyVSAvoiddistance measurement accuracy
Core Design Contradiction:
ProductivityVSMeasurement precision

Solution Approach 1:

The patent changes the parameter used for distance determination from direct location coordinates to reference signal received power threshold. By adjusting this parameter, the system can accommodate signal obstruction effects while maintaining resource utilization efficiency, as the reference signal received power naturally reflects actual signal strength regardless of obstruction

Inventive Principle:
Principle #35Parameter changes

3Reliability

If HARQ feedback is sent by all terminals within service distance, then data transmission reliability is improved, but unnecessary retransmissions occur and resource utilization decreases

Engineering Contradiction:
Improvedata transmission reliabilityVSAvoidresource utilization efficiency
Core Design Contradiction:
ReliabilityVSLoss of energy

Solution Approach 1:

The patent applies local quality by differentiating terminal behavior based on their specific distance from the second terminal. Terminals within the service distance (determined by reference signal received power threshold) send HARQ feedback, while terminals outside this distance do not. This localized differentiation ensures reliable transmission for nearby terminals while avoiding unnecessary retransmissions for distant terminals

Inventive Principle:
Principle #3Local quality

Data Source

PatentEP3952356B1Communication method and apparatus
Publication Date: 2025.09.24 HUAWEI TECH CO LTD
  • EP3952356B1 patent drawingFigure 1
  • EP3952356B1 patent drawingFigure 2
  • EP3952356B1 patent drawingFigure 3

AI summary

This application provides a communication method and apparatus, and relates to the field of communication technologies, and in particular, to V2X, intelligent driving, an intelligent connected vehicle, and the like, to ensure service data transmission reliability. The method includes: A first terminal receives service data from a second terminal. If a distance value between the first terminal and the second terminal falls within a preset distance range, the first terminal sends, based on a preset condition, acknowledgment information indicating that the service data is received successfully or unsuccessfully to the second terminal. The preset distance range is determined based on a first preset distance value and a second preset distance value, and the second preset distance value is greater than the first preset distance value. The method is applied to a communication process between terminals.