Cellular V2X Resource Selection for 5G–Legacy Spectrum Sharing

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Solution Overview

Problem

Existing wireless communication systems face challenges in efficiently sharing radio frequency spectrum bands between next-generation 5G devices and legacy devices for vehicle-to-everything (V2X) networks, leading to conflicts in resource selection and priority management for safety and non-safety messages.

Innovation Solution

5G devices decode control channel transmissions from legacy devices to identify available resource blocks, generate preambles decodable by legacy devices to reserve resources, and adjust transmission opportunities (TxOP) to facilitate prioritized sharing and coexistence.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If 5G devices and legacy devices share the same radio frequency spectrum band for V2X communications, then spectrum utilization efficiency is improved, but resource selection conflicts and priority management difficulties arise

Engineering Contradiction:
Improvespectrum utilization efficiencyVSAvoidresource selection conflict management
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The patent segments the shared spectrum band into different sub-bands or time periods, allowing 5G devices and legacy devices to access specific portions of the spectrum without conflict. This segmentation resolves resource selection conflicts while maintaining overall spectrum utilization efficiency.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent implements preliminary actions where devices perform listen-before-talk procedures and transmit preambles before actual data transmission. This preliminary action phase allows devices to reserve resources and indicate their transmission intentions, preventing conflicts during the actual communication.

Inventive Principle:
Principle #10Preliminary action

2Reliability

If safety messages are given higher priority than non-safety messages, then communication reliability for critical V2X functions is improved, but resource allocation complexity increases

Engineering Contradiction:
Improvesafety message delivery reliabilityVSAvoidpriority-based resource allocation
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent applies local quality by treating safety messages and non-safety messages differently in terms of resource allocation and priority handling. Safety messages receive higher priority and dedicated resource allocation, while non-safety messages use standard sharing mechanisms, resolving the contradiction between reliability and complexity.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The patent introduces an intermediary mechanism (such as a scheduler or resource manager) that mediates between safety and non-safety message requirements. This intermediary handles the complex priority-based resource allocation automatically, reducing the complexity burden on individual devices.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Speed

If 5G devices transmit without requiring legacy device acknowledgment, then transmission speed is improved, but coexistence and interference management become more difficult

Engineering Contradiction:
Improve5G device transmission speedVSAvoidinterference from legacy devices
Core Design Contradiction:
SpeedVSObject-affected harmful factors

Solution Approach 1:

The patent implements preliminary action through preamble transmission and listen-before-talk procedures. 5G devices transmit preambles that legacy devices can detect, allowing legacy devices to back off or adjust their transmissions before 5G devices begin data transmission, thereby reducing interference while maintaining high 5G transmission speeds.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent converts the potential harm of legacy device interference into a beneficial mechanism by using legacy device transmissions as a basis for 5G device resource selection. 5G devices decode legacy device preambles and control channels to identify available resources, turning what was originally harmful interference into useful information for efficient resource allocation.

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

Data Source

PatentEP4102904B1Cellular vehicle-to-everything design principles
Publication Date: 2025.08.06 QUALCOMM INC
  • EP4102904B1 patent drawingFigure 1
  • EP4102904B1 patent drawingFigure 2
  • EP4102904B1 patent drawingFigure 3

AI summary

Methods, systems, and devices for wireless communication are described. A 5G device may decode a control channel transmission of a safety message in a vehicle-to-everything system during a first portion of a time period. The 5G device may identify, based at least in part on the decoding, a pool of resource blocks (RBs) that are available for the time period. The 5G device may select a subset of RBs from the available pool of RBs for a transmission during a second portion of the time period.