Terminal Uplink Power Prioritization Across Candidate Cells

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Solution Overview

Problem

In future radio communication systems, the appropriate control of uplink (UL) transmission to multiple candidate cells is not clear, leading to potential deterioration in communication quality when UL transmissions overlap or collide with each other.

Innovation Solution

A terminal allocates power to multiple ULs based on a priority order, ensuring that PRACH transmissions to candidate cells other than the primary cell are given a lower priority than the serving cell, and transmits these ULs accordingly.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If UL transmission is enabled for multiple candidate cells to improve communication capacity and mobility, then system adaptability and communication quality are improved, but UL transmission control becomes complex and power allocation difficulty increases

Engineering Contradiction:
Improvecommunication qualityVSAvoidUL transmission control
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent applies parameter changes by dynamically adjusting the priority order parameter for PRACH transmission based on cell type (serving cell vs. candidate cell). This allows the system to maintain adaptability for multiple cell transmissions while controlling complexity through a standardized priority parameter that can be modified without changing the overall power allocation mechanism.

Inventive Principle:
Principle #35Parameter changes

2Ease of operation

If power is allocated equally to multiple UL transmissions to maintain fairness, then resource allocation simplicity is improved, but communication quality deteriorates due to power insufficiency in overlapping transmissions

Engineering Contradiction:
Improvepower allocationVSAvoidcommunication quality
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The patent applies local quality by assigning different priority levels to different types of UL transmissions. Specifically, PRACH transmission on serving cells receives higher priority than PRACH transmission on candidate cells, allowing power to be locally optimized for each transmission type based on its importance to communication quality.

Inventive Principle:
Principle #3Local quality

3Reliability

If PRACH transmission priority is increased for candidate cells to improve random access success rate, then access reliability is improved, but total transmit power may be exceeded and other transmissions may be affected

Engineering Contradiction:
Improverandom access success rateVSAvoidtotal transmit power
Core Design Contradiction:
ReliabilityVSLoss of energy

Solution Approach 1:

The patent changes the priority parameter for PRACH transmission on candidate cells to be lower than serving cells. This parameter adjustment ensures that when total power limits are reached, candidate cell PRACH transmissions can be appropriately deprioritized, preventing power overflow while maintaining adequate access success rates.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP4704474A1Terminal, wireless communication method, and base station
Publication Date: 2026.03.04 NTT DOCOMO INC
  • EP4704474A1 patent drawingFigure 1A~1B
  • EP4704474A1 patent drawingFigure 2
  • EP4704474A1 patent drawingFigure 3A~3B

AI summary

A terminal according to one aspect of the present disclosure includes a control section that allocates power to a plurality of uplinks (ULs), based on a priority order, when a total transmit power exceeds a specific value, and a transmitting section that transmits the plurality of ULs, wherein a priority order that is the same as or lower than a priority order of a serving cell is configured for a physical random access channel (PRACH) transmission on a candidate cell other than a primary cell (PCell) and the serving cell among the plurality of ULs. According to one aspect of the present disclosure, a UL transmission is appropriately controlled even when the UL transmission is possible for one or a plurality of candidate cells.