Autonomous Transmission Power Control for Inter-Vehicle Radio Links

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Solution Overview

Problem

In inter-automobile communication systems without a base station, it is challenging for automobile communication devices to autonomously set optimal transmission powers, leading to communication congestion and throughput drops due to the lack of base station intervention.

Innovation Solution

A radio communication apparatus with a transmission power control method that adjusts transmission power based on the distribution of peripheral communication devices by estimating transmission losses and reception powers, using a configuration with a transmission power control section, on-board radio section, and on-board control section to autonomously set and adjust transmission powers, thereby limiting the communicable area and reducing congestion.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Extent of automation

If direct communication is carried out between automobile communication devices without base station intervention, then communication autonomy and device independence are improved, but transmission power control capability deteriorates leading to communication congestion and throughput drops

Engineering Contradiction:
Improvecommunication autonomyVSAvoidtransmission power control capability
Core Design Contradiction:
Extent of automationVSEase of operation

Solution Approach 1:

The patent implements self-service by enabling each automobile communication device to autonomously determine its own transmission power level. The device estimates the number of peripheral communication devices and calculates appropriate transmission power without requiring base station intervention, thus maintaining communication autonomy while solving the power control problem through self-directed decision-making algorithms

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The patent employs feedback mechanisms where each communication device continuously monitors the communication environment, estimates the density of peripheral devices, and adjusts transmission power based on this feedback. The device uses received signal strength measurements and peer device information to dynamically adapt power levels, creating a closed-loop control system that operates autonomously without base station management

Inventive Principle:
Principle #23Feedback

2Area of stationary object

If transmission power is increased to maintain communication coverage, then communicable area is improved, but radio communication congestion worsens due to more devices being in range

Engineering Contradiction:
Improvecommunicable areaVSAvoidradio communication throughput
Core Design Contradiction:
Area of stationary objectVSProductivity

Solution Approach 1:

The patent applies dynamics by making the communicable area variable rather than fixed. Each device dynamically adjusts its transmission power based on real-time estimates of peripheral device density, causing the communicable area to expand or contract adaptively. This dynamic control ensures that when devices are dense, the communicable area shrinks to reduce congestion, while when devices are sparse, the area expands to maintain coverage

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent implements parameter changes by modifying transmission power levels based on environmental conditions. The system changes the power parameter dynamically according to the estimated number of peripheral communication devices, thereby controlling the size of the communicable area and preventing congestion through parameter adaptation rather than fixed settings

Inventive Principle:
Principle #35Parameter changes

3Productivity

If transmission power is autonomously determined based on peripheral device distribution, then communication congestion is reduced, but transmission power determination complexity increases

Engineering Contradiction:
Improvecommunication efficiencyVSAvoidtransmission power determination complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The patent uses copying by having each communication device replicate the base station's power control functionality. Each device creates a local copy of the power determination logic, using simplified algorithms that mirror centralized control decisions. This allows autonomous operation while keeping individual device complexity manageable through replicated, standardized control routines

Inventive Principle:
Principle #26Copying

Data Source

PatentEP1976142B1Radio communication apparatus and transmission power control method
Publication Date: 2016.06.29 NEC CORP
  • EP1976142B1 patent drawingFigure 1
  • EP1976142B1 patent drawingFigure 2
  • EP1976142B1 patent drawingFigure 3

AI summary

A radio communication apparatus which performs a direct communication with a counter radio communication apparatus is provided. The radio communication apparatus includes a radio section configured to receive from the counter radio communication apparatus, a first radio signal which contains a first transmission power setting value, and to measure a first reception power value; and a transmission power control section configured to determine a second transmission power setting value as a setting value of power at transmission of a second radio signal to the counter radio communication apparatus based on the first transmission power setting value and the first reception power value.