HARQ-ACK Codebook Handling for Unavailable Uplink Occasions

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Solution Overview

Problem

Existing wireless communication systems face challenges with delayed HARQ-ACK codebooks, particularly in scenarios where initial uplink transmission occasions are not available, leading to inefficiencies in HARQ-ACK information transmission.

Innovation Solution

The method involves constructing a first HARQ-ACK codebook for transmission on a first uplink occasion and determining part of the information to be transmitted with a second HARQ-ACK codebook on a later occasion, where the first occasion is not available, ensuring continuous and efficient HARQ-ACK information transmission.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of time

If HARQ-ACK codebook is constructed for transmission on a scheduled uplink transmission occasion, then the transmission timing is optimized, but the transmission may fail when the uplink occasion is not available

Engineering Contradiction:
Improvetransmission delayVSAvoidtransmission availability
Core Design Contradiction:
Loss of timeVSReliability

Solution Approach 1:

The patent implements dynamic adaptation of HARQ-ACK codebook transmission by determining whether to transmit the codebook on the originally scheduled uplink transmission occasion or to delay transmission to a later occasion. The user equipment dynamically selects the transmission timing based on availability of the scheduled occasion, resolving the contradiction between optimized timing and reliable transmission.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent changes the transmission timing parameter of the HARQ-ACK codebook based on the availability of the scheduled uplink transmission occasion. When the scheduled occasion is not available, the system transitions to a later transmission occasion, effectively changing the time parameter to maintain transmission reliability while minimizing delay.

Inventive Principle:
Principle #35Parameter changes

2Productivity

If HARQ-ACK information is transmitted on the scheduled uplink occasion, then transmission efficiency is maximized, but system complexity increases when handling unavailable occasions

Engineering Contradiction:
Improvetransmission efficiencyVSAvoidtransmission control complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The patent employs feedback mechanisms where the user equipment determines the availability of the scheduled uplink transmission occasion and adjusts transmission decisions accordingly. This feedback loop simplifies the control logic by using availability information to make straightforward transmission or delay decisions, reducing the complexity of handling unavailable occasions.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The patent performs preliminary determination of uplink transmission occasion availability before actual transmission. By assessing availability in advance and pre-determining whether to transmit on the scheduled occasion or delay to a later occasion, the system avoids complex real-time decision-making during transmission, thereby reducing overall control complexity while maintaining efficiency.

Inventive Principle:
Principle #10Preliminary action

3Reliability

If partial HARQ-ACK information is transmitted on a later occasion, then transmission reliability is improved, but transmission time is extended

Engineering Contradiction:
Improveinformation transmission reliabilityVSAvoidtransmission timing
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The patent applies partial action by transmitting only the necessary HARQ-ACK information on the later uplink transmission occasion when the scheduled occasion is unavailable. Instead of transmitting all information at once or repeatedly, the system selectively transmits the required partial information at the appropriate later time, balancing reliability improvement with minimal time extension.

Inventive Principle:
Principle #16Partial or excessive action

Data Source

PatentEP4252376B1HARQ-ACK codebook construction
Publication Date: 2026.03.25 LENOVO (SINGAPORE) PTE LTD
  • EP4252376B1 patent drawingFigure 1
  • EP4252376B1 patent drawingFigure 2
  • EP4252376B1 patent drawingFigure 3

AI summary

Apparatuses, methods, and systems are disclosed for HARQ-ACK codebook construction. One method (500) includes constructing (502) a first HARQ-ACK codebook based on first HARQ-ACK information. The first HARQ-ACK codebook is scheduled to be transmitted on a first uplink transmission occasion. The method (500) includes determining (504) at least part of the first HARQ-ACK information to be transmitted together with second HARQ-ACK information in response to the first uplink transmission occasion not being available for transmission. The second HARQ-ACK information is scheduled to be transmitted later than the first uplink transmission occasion. The method (500) includes transmitting (506) a second HARQ-ACK codebook on a second uplink transmission occasion. The second HARQ-ACK codebook is based on at least the part of the first HARQ-ACK information and the second HARQ-ACK information, and the first uplink transmission occasion starts earlier than the second uplink transmission occasion.