Wireless Device Output Power for Mixed TTI Carrier Aggregation

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Solution Overview

Problem

Existing LTE systems lack a well-defined method for determining maximum output power when configured with different transmission time index (TTI) patterns in carrier aggregation scenarios, leading to inconsistent wireless device behavior and potential interference issues.

Innovation Solution

A method for wireless devices and network nodes to determine maximum output power by considering different TTI patterns across serving cells, using a reference time period to evaluate power based on the longest or combined TTI lengths, ensuring consistent power management and reduced interference.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If different TTI patterns are configured across serving cells in carrier aggregation, then system flexibility and adaptability are improved, but device behavior consistency deteriorates due to lack of well-defined power determination methods

Engineering Contradiction:
ImproveTTI pattern configuration flexibilityVSAvoiddevice behavior consistency
Core Design Contradiction:
Adaptability or versatilityVSReliability

Solution Approach 1:

The patent applies parameter changes by introducing a reference time period parameter that adapts to different TTI patterns. The reference time period is determined based on the longest TTI among configured serving cells, allowing the power determination method to accommodate varying TTI configurations while maintaining consistent device behavior through a unified reference framework.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent implements universality by creating a universal reference time period that serves all serving cells regardless of their individual TTI patterns. This reference time period acts as a common denominator for power determination across heterogeneous TTI configurations, ensuring consistent device behavior while supporting diverse carrier aggregation scenarios.

Inventive Principle:
Principle #6Universality (Multi-functionality)

2Device complexity

If power determination is not well-defined for different TTI patterns, then device complexity is reduced, but interference control deteriorates due to inconsistent power management

Engineering Contradiction:
Improvepower determination complexityVSAvoidinterference
Core Design Contradiction:
Device complexityVSObject-generated harmful factors

Solution Approach 1:

The patent introduces a reference time period as an intermediary element that mediates between different TTI patterns and power determination. This intermediary provides a standardized basis for calculating maximum output power across varying TTI configurations, enabling consistent interference control without requiring complex device-specific power determination logic.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Ease of operation

If maximum output power is not properly evaluated considering different TTI lengths, then ease of operation is improved, but power management consistency deteriorates

Engineering Contradiction:
Improvepower configuration simplicityVSAvoidpower management consistency
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The patent changes the evaluation parameter from individual cell-specific TTI durations to a unified reference time period based on the longest TTI. This parameter transformation simplifies power configuration operations while ensuring consistent power management across all serving cells by providing a common evaluation basis that accounts for the most restrictive TTI pattern.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP3998805B1Output power configured with different tti
Publication Date: 2025.07.09 TELEFONAKTIEBOLAGET LM ERICSSON (PUBL)
  • EP3998805B1 patent drawingFigure 1
  • EP3998805B1 patent drawingFigure 2
  • EP3998805B1 patent drawingFigure 3~4

AI summary

According to certain embodiments, a method by a wireless device is provided for determining a maximum output power. The method includes obtaining, by the wireless device, a first time resource for transmitting a first signal in a first cell on a first carrier and a second time resource for transmitting a second signal in a second cell on a second carrier. Based on the first time resource and the second time resource, the maximum output power is determined. The first signal and the second signal are transmitted based on the determined maximum output power.