Carrier Aggregation Random Access Acknowledgement Reception

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Solution Overview

Problem

Existing wireless communication systems face inefficiencies in performing random access procedures and transmitting/receiving control information in carrier aggregation-based systems, particularly in handling acknowledgement information during uplink signal transmissions.

Innovation Solution

A method and apparatus for a user equipment (UE) in a carrier aggregation-based wireless communication system, where uplink resource allocation information is received through a first cell, and an uplink signal is transmitted on a second cell using this information, with acknowledgement information being received via a specific cell different from the first cell during random access procedures, and via the first cell during non-random access procedures.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If acknowledgement information is always received via the first cell (PCell), then control information transmission is simplified, but random access procedure efficiency deteriorates due to suboptimal resource utilization

Engineering Contradiction:
Improvecontrol information transmission simplicityVSAvoidrandom access procedure efficiency
Core Design Contradiction:
Ease of operationVSProductivity

Solution Approach 1:

The patent applies dynamics by making the acknowledgement information reception cell dynamic rather than fixed. The UE determines whether to receive acknowledgement information via the first cell or second cell based on the random access indicator value, allowing the system to adaptively switch between reception paths to optimize for different operational scenarios (random access vs. non-random access procedures).

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent applies local quality by assigning different reception characteristics to different types of uplink transmissions. Random access procedure acknowledgements are received via the second cell (SCell) to leverage its resources, while non-random access acknowledgements are received via the first cell (PCell) for reliability. This localized optimization resolves the contradiction by tailoring the reception path to the specific procedure type.

Inventive Principle:
Principle #3Local quality

2Productivity

If acknowledgement information for random access is received via the second cell (SCell), then random access procedure efficiency is improved, but control information transmission complexity increases

Engineering Contradiction:
Improverandom access procedure efficiencyVSAvoidcontrol information reception complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The patent reduces complexity through dynamic cell selection based on the random access indicator. Rather than maintaining complex logic to determine which cell to use for each acknowledgement type, the system uses the indicator to directly select the appropriate reception cell, simplifying the overall control flow while maintaining optimization for random access procedures.

Inventive Principle:
Principle #15Dynamics

3Productivity

If different cells are used for different procedures, then resource utilization is optimized, but system complexity increases

Engineering Contradiction:
Improveresource utilization efficiencyVSAvoidcell selection logic complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The patent applies local quality by optimizing resource utilization for specific procedure types without requiring complex system-wide changes. The UE uses the random access indicator to locally determine the appropriate acknowledgement reception cell based on whether the current transmission is part of a random access procedure, achieving localized resource optimization with minimal added complexity.

Inventive Principle:
Principle #3Local quality

Data Source

PatentEP2797377B1Method and apparatus for performing random access process in wireless communication system
Publication Date: 2018.12.05 LG ELECTRONICS INC
  • EP2797377B1 patent drawingFigure 1
  • EP2797377B1 patent drawingFigure 2(a)~2(b)
  • EP2797377B1 patent drawingFigure 3

AI summary

The present invention relates to a wireless communication system. In detail, the present invention is a method in which user equipment for which a plurality of cells is constituted receives control information in a carrier aggregation-based wireless communication system, and an apparatus for the method. The method comprises: a step of receiving, through a first cell, uplink resource allocation information for a second cell; a step of transmitting an uplink signal on the second cell using the uplink resource allocation information; and a step of receiving response information to the uplink signal. The response information is received via a specific cell rather than the first cell when the uplink signal is transmitted by a random access process, and the response information is received via the first cell when the uplink signal is transmitted by a non-random access process.