DCI-Based HARQ-ACK Codebook Timing for Multi-Cell Wireless Links

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Solution Overview

Problem

Existing wireless communication systems face inefficiencies in signal transmission and reception processes, particularly in handling HARQ-ACK reports for multiple serving cells and HARQ processes.

Innovation Solution

Implementing a specific type codebook-based HARQ-ACK configuration for efficient reporting of ACK/NACK bits, where lower indexed serving cells, HARQ processes, and codeblock groups are mapped in a structured manner, and determining time resources based on downlink control information for one-shot-based transmission.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If traditional HARQ-ACK reporting methods are used for multiple serving cells and HARQ processes, then the system can maintain basic communication functionality, but the signal transmission and reception efficiency deteriorates due to inadequate handling of multiple ACK/NACK bits

Engineering Contradiction:
Improvesignal transmission efficiencyVSAvoidHARQ-ACK reporting accuracy
Core Design Contradiction:
ProductivityVSLoss of information

Solution Approach 1:

The patent segments the HARQ-ACK codebook into multiple groups, where each group corresponds to a specific serving cell or HARQ process. This segmentation allows for organized and efficient management of multiple ACK/NACK bits, improving the reporting accuracy while maintaining scalability for multiple serving cells.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent introduces a new dimension for organizing HARQ-ACK bits by using codebook groups that can be indexed and structured in a hierarchical manner. This dimensional organization transforms the flat structure of traditional HARQ-ACK reporting into a multi-dimensional framework, enabling more efficient handling of multiple serving cells and HARQ processes.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Measurement precision

If codebook-based HARQ-ACK reporting is implemented, then the reporting accuracy improves through structured mapping, but the device complexity increases due to the need for managing codebook groups and subpatterns

Engineering Contradiction:
ImproveHARQ-ACK reporting accuracyVSAvoidcodebook management complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent creates a universal codebook structure that can accommodate multiple serving cells and HARQ processes through a standardized grouping mechanism. This universal framework allows the same codebook management approach to be applied across different scenarios, reducing the overall complexity compared to implementing separate management mechanisms for each case.

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

Solution Approach 2:

The patent performs preliminary organization of HARQ-ACK bits into codebook groups and subpatterns before the actual reporting process. This pre-structuring of the codebook allows for more efficient encoding and transmission, reducing the computational complexity during the actual HARQ-ACK reporting while maintaining high accuracy.

Inventive Principle:
Principle #10Preliminary action

3Loss of time

If one-shot-based transmission of ACK/NACK is implemented, then the transmission time is reduced, but the resource allocation complexity increases due to the need for precise time resource determination

Engineering Contradiction:
ImproveHARQ-ACK transmission timeVSAvoidtime resource allocation complexity
Core Design Contradiction:
Loss of timeVSDevice complexity

Solution Approach 1:

The patent determines the time resources for one-shot HARQ-ACK transmission in advance through pre-configured parameters and rules. This preliminary determination of time resources allows for efficient one-shot transmission without requiring complex real-time resource allocation, reducing both transmission time and computational complexity.

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentEP4057537B1Method and device for transmitting or receiving signal in wireless communication system
Publication Date: 2026.02.18 LG ELECTRONICS INC
  • EP4057537B1 patent drawingFigure 1
  • EP4057537B1 patent drawingFigure 2
  • EP4057537B1 patent drawingFigure 3

AI summary

A UE according to an embodiment of the present disclosure receives DCI of a DL grant format through a PDCCH and transmits a HARQ-ACK report, in a state in which the DCI of the DL grant format indicates a specific type codebook-based HARQ-ACK report for one-shot-based transmission of ACK/NACKs for all HARQ processes of serving cells, the UE may determine a time resource for the specific type codebook-based HARQ-ACK report based on whether a PDSCH is scheduled by the DCI.