Speed-Based Transmission Format Selection for V2X

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Solution Overview

Problem

In vehicle-to-everything (V2x) communication, traditional link adaptation methods are impractical due to high latency and signaling overhead, especially in one-to-many topologies, making it challenging to optimize spectral efficiency and meet latency requirements for safety messages.

Innovation Solution

Implementing open-loop link adaptation that selects a transmission format based on parameters available at the transmitter, such as vehicle speed and packet size, without relying on receiver feedback, to adaptively optimize spectral efficiency and meet latency requirements.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If traditional closed-loop link adaptation protocols are used in V2x communication, then link spectral efficiency can be maximized through feedback-based transmission format selection, but the feedback load becomes too large and latency requirements cannot be met due to the one-to-many topology

Engineering Contradiction:
Improvelink spectral efficiencyVSAvoidlatency
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The patent extracts the essential function of link adaptation (selecting optimal transmission format) and implements it independently at the transmitter using only locally available information (speed, packet size). This removes the dependency on receiver feedback, eliminating feedback load and latency while maintaining the ability to adapt transmission parameters to channel conditions.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The transmitter pre-determines the transmission format by estimating channel conditions based on its own speed and packet size before transmission occurs. This preliminary action eliminates the need for subsequent feedback exchanges, allowing the system to meet strict latency requirements while still achieving adaptive transmission.

Inventive Principle:
Principle #10Preliminary action

2Adaptability or versatility

If closed-loop link adaptation with feedback signaling is implemented, then transmission format can be optimized based on receiver measurements, but the signaling overhead becomes impractical for V2x scenarios

Engineering Contradiction:
Improvetransmission format optimizationVSAvoidsignaling overhead
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The transmitter performs link adaptation independently using its own speed information and packet size to determine the optimal transmission format. This self-service approach eliminates the need for receiver feedback and complex signaling protocols, dramatically reducing signaling overhead while maintaining adaptability to channel conditions.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The patent introduces the transmitter's own speed and packet size as intermediary parameters that correlate with channel conditions. These local parameters serve as proxies for what would otherwise require complex feedback signaling, enabling transmission format optimization without the overhead of traditional closed-loop protocols.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Productivity

If transmission format is selected without considering vehicle speed, then simpler protocols can be used, but spectral efficiency cannot be optimized for varying mobility conditions

Engineering Contradiction:
Improvespectral efficiencyVSAvoidtransmission format selection complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The patent changes the transmission format selection based on the vehicle's speed parameter. By using speed as a key input variable along with packet size, the system adapts transmission parameters (modulation, coding, resource allocation) to match mobility conditions, thereby optimizing spectral efficiency without requiring complex feedback-based protocols.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP3354048B1Speed dependent transmission format for vehicular or d2d transmission
Publication Date: 2021.09.08 TELEFONAKTIEBOLAGET LM ERICSSON (PUBL)
  • EP3354048B1 patent drawingFigure 1
  • EP3354048B1 patent drawingFigure 2
  • EP3354048B1 patent drawingFigure 3

AI summary

A method and system for selecting a transmission format of a first wireless device in a wireless communication network are provided. According to one aspect, a method for selecting a transmission format includes determining a speed of the first wireless device, selecting a transmission format based on the speed of the first wireless device.