UE Random Access Power Control via PC Correction

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Solution Overview

Problem

Current wireless communication systems face inefficiencies in transmitting random access preambles and signaling for system access, leading to interference on uplink resources and suboptimal power control.

Innovation Solution

A method and apparatus for a user equipment (UE) that sends a random access preamble, receives a random access response with power control and timing advance corrections, and determines transmit power based on these corrections and power offsets between channels to efficiently access the system, using Implicit Radio Network Temporary Identifiers (I-RNTI) for identification.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If random access preambles and signaling are transmitted for system access, then system access capability is improved, but uplink interference increases and power control becomes suboptimal

Engineering Contradiction:
Improvesystem access capabilityVSAvoiduplink interference
Core Design Contradiction:
Ease of operationVSObject-generated harmful factors

Solution Approach 1:

The patent changes the parameter of transmit power by introducing PC correction values received from the base station. The UE adjusts its transmit power for the random access preamble based on these correction values, which are specifically designed to optimize power levels and reduce uplink interference while maintaining system access capability.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent implements a feedback mechanism where the base station sends PC correction values to the UE based on the received signal quality of random access preambles. The UE uses this feedback to adjust its transmit power, creating a closed-loop system that reduces interference while maintaining access capability.

Inventive Principle:
Principle #23Feedback

2Reliability

If random access preambles are transmitted with higher power to improve detection reliability, then detection reliability is improved, but uplink interference increases

Engineering Contradiction:
Improvedetection reliabilityVSAvoiduplink interference
Core Design Contradiction:
ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The patent changes the transmit power parameter dynamically by applying PC corrections received from the base station. Instead of using fixed or maximum power levels, the UE adjusts its transmit power to the optimal level needed for reliable detection, thereby maintaining detection reliability while minimizing uplink interference.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The UE autonomously adjusts its transmit power based on PC correction values received in the random access response. This self-service mechanism allows the UE to automatically optimize its power level without manual intervention, achieving reliable detection while minimizing interference to other uplink transmissions.

Inventive Principle:
Principle #25Self-service

3Device complexity

If conventional power control methods are used for random access signaling, then implementation simplicity is maintained, but power control efficiency deteriorates

Engineering Contradiction:
Improveimplementation simplicityVSAvoidpower control efficiency
Core Design Contradiction:
Device complexityVSProductivity

Solution Approach 1:

The patent introduces PC correction values as new parameters in the power control mechanism. These corrections are transmitted efficiently through the random access response, allowing the system to achieve improved power control efficiency without significantly increasing implementation complexity, as the corrections are integrated into existing signaling procedures.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP3554180B1Method and apparatuses for random access to a wireless communication system
Publication Date: 2021.05.05 QUALCOMM INC
  • EP3554180B1 patent drawingFigure 1
  • EP3554180B1 patent drawingFigure 2
  • EP3554180B1 patent drawingFigure 3

AI summary

Techniques for wireless communication at a user equipment, UE, are described. In an aspect, The UE may send a random access preamble for system access; receive a random access response on a Physical Downlink Control Channel, PDCCH, and/or a Physical Downlink Shared Channel, PDSCH, with a power control, PC, correction indicating adjustment of the transmit power of the UE, a timing advance indicating adjustment to the transmit timing of the UE, uplink resources indicating resources granted to the UE for uplink transmission, and an Implicit Radio Network Temporary Identifier, I-RNTI, identifying the UE during system access; determine transmit power of a message based on the PC correction; and send the message with the determined transmit power.