Cellular V2X Spectrum Sharing for 5G-Legacy Coexistence

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Solution Overview

Problem

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

Innovation Solution

5G devices decode control channel transmissions of legacy devices to identify available resource blocks, generate preambles decodable by legacy devices, and adjust transmission opportunities to ensure co-channel coexistence and prioritize sharing, thereby avoiding interference.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

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 transmission interference increase

Engineering Contradiction:
Improvespectrum sharing capabilityVSAvoidtransmission interference
Core Design Contradiction:
Adaptability or versatilityVSObject-affected harmful factors

Solution Approach 1:

The patent segments the shared radio frequency spectrum band into different time periods (first portion and second portion) and identifies available resource blocks based on legacy device transmissions. This temporal and frequency segmentation allows 5G devices to access spectrum resources without interfering with legacy devices, resolving the contradiction between spectrum sharing capability and transmission interference.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent implements preliminary actions by having 5G devices decode control channel transmissions during the first portion of time periods before selecting resource blocks for their own transmissions in the second portion. This preliminary decoding and identification of available resources prevents interference before it occurs, enabling coexistence of 5G and legacy devices in the shared spectrum.

Inventive Principle:
Principle #10Preliminary action

2Productivity

If 5G devices decode control channels and select available resource blocks, then resource allocation efficiency is improved, but processing time and latency increase

Engineering Contradiction:
Improveresource allocation efficiencyVSAvoidprocessing latency
Core Design Contradiction:
ProductivityVSLoss of time

Solution Approach 1:

The patent employs periodic action by dividing time into repeated cycles of control channel decoding (first portion) followed by resource block selection and transmission (second portion). This periodic structure enables efficient resource allocation through systematic monitoring and selection, while the regular rhythm optimizes processing latency by avoiding random delays.

Inventive Principle:
Principle #19Periodic action

3Reliability

If legacy devices transmit control information continuously, then channel availability is improved, but 5G device transmission opportunities are reduced

Engineering Contradiction:
Improvechannel availabilityVSAvoid5G device transmission opportunity
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The patent implements dynamics by allowing the allocation of time periods and resource blocks to be flexible rather than fixed. The system dynamically identifies available resource blocks based on actual legacy device transmissions and adjusts 5G device transmission opportunities accordingly, optimizing both channel availability for legacy devices and transmission opportunities for 5G devices through adaptive resource management.

Inventive Principle:
Principle #15Dynamics

Data Source

PatentEP4593485A1Cellular vehicle-to-everything design principles
Publication Date: 2025.07.30 QUALCOMM INC
  • EP4593485A1 patent drawingFigure 1
  • EP4593485A1 patent drawingFigure 2
  • EP4593485A1 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.