Random Access Preamble Transmission Power Ramping Control

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Solution Overview

Problem

The increasing number of user equipment (UEs) and data/control information in new radio communication systems pose challenges in efficiently transmitting and receiving data using limited radio resources, while also requiring reduced latency and support for high-frequency bands.

Innovation Solution

A method for transmitting a random access preamble in a wireless communication system involves performing a first random access preamble transmission at a specific power and a second transmission if the response is not received successfully, with the second transmission power determined based on a power ramping counter value, and using different or the same synchronization signal blocks and random access channels.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If the number of user equipments and data transmission is increased to satisfy rapidly increasing data throughput demands, then data capacity and network capability are improved, but radio resources become more limited and resource efficiency deteriorates

Engineering Contradiction:
Improvedata throughputVSAvoidradio resources
Core Design Contradiction:
ProductivityVSQuantity of substance

Solution Approach 1:

The patent segments the random access procedure into multiple stages with different power levels. The UE first transmits a random access preamble at a lower first power level, and only if no response is received does it transmit again at a higher second power level. This segmentation allows the system to handle more UEs efficiently by reducing unnecessary high-power transmissions, thereby improving resource utilization while maintaining productivity.

Inventive Principle:
Principle #1Segmentation

2Reliability

If random access preamble retransmission is performed at higher power to ensure successful communication, then reliability is improved, but transmission power consumption increases

Engineering Contradiction:
Improvecommunication success rateVSAvoidtransmission power
Core Design Contradiction:
ReliabilityVSUse of energy by moving object

Solution Approach 1:

The patent implements a dynamic power adjustment mechanism where the transmission power is not fixed but adapts based on reception conditions. The UE transmits at a lower first power level initially, and only increases to a second power level if the first transmission fails to elicit a response. This dynamic approach maintains reliability by ensuring successful communication when needed, while minimizing energy consumption by avoiding unnecessary high-power transmissions.

Inventive Principle:
Principle #15Dynamics

3Use of energy by moving object

If power ramping counter is maintained across different synchronization signal blocks to reduce power consumption, then energy efficiency is improved, but interference to other UEs may increase

Engineering Contradiction:
Improvetransmission powerVSAvoidinterference to other UEs
Core Design Contradiction:
Use of energy by moving objectVSObject-affected harmful factors

Solution Approach 1:

The patent applies local quality by allowing each UE to maintain its power ramping counter independently based on its specific reception conditions for different synchronization signal blocks. Each UE adjusts its transmission power according to its local channel conditions and reception success, rather than using a uniform approach. This enables energy efficiency for each UE while minimizing interference to others, as each UE only increases power when genuinely necessary for its own communication.

Inventive Principle:
Principle #3Local quality

Data Source

PatentEP3471495B1Method and user equipment for transmitting random access preamble
Publication Date: 2021.09.01 LG ELECTRONICS INC
  • EP3471495B1 patent drawingFigure 1
  • EP3471495B1 patent drawingFigure 2
  • EP3471495B1 patent drawingFigure 3

AI summary

In the present invention, when a UE transmits a random access preamble, the UE maintains a power ramping counter used for determination of a transmission power equally to a value of previous transmission without incrementing the power ramping counter if a target synchronization signal block is changed differently from a previous random access preamble transmission.