HARQ Feedback Codebook Selection During Cell DTX/DRX Inactivity

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Solution Overview

Problem

In cell discontinuous transmission (DTX)/discontinuous reception (DRX) mechanisms, unnecessary HARQ feedbacks occur, leading to waste of feedback resources due to the terminal performing HARQ feedback according to existing solutions.

Innovation Solution

A terminal determines a HARQ feedback codebook based on the inactive period of DTX or DRX in a target cell, optimizing HARQ feedback by reducing unnecessary feedbacks and resource waste.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of energy

If the terminal performs HARQ feedback according to existing solutions in cell DTX/DRX mechanisms, then the HARQ feedback is sent, but waste of feedback resources is caused

Engineering Contradiction:

Improvefeedback resource wasteVSAvoidHARQ feedback reliability

Core Design Contradiction:

Loss of energyVSReliability

Solution Approach 1:

The patent applies dynamics by making the HARQ feedback behavior adaptive to the cell's transmission state. The terminal dynamically determines whether to send HARQ feedback based on whether the downlink transmission corresponds to an active period or inactive period of cell DTX/DRX, transforming a static feedback mechanism into a dynamic one that responds to changing network conditions.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The patent changes the parameter of HARQ feedback transmission by introducing a determination step that evaluates the cell's DTX/DRX state. The terminal modifies its feedback transmission parameter (send or not send) based on the inactive period information, effectively using parameter change to avoid unnecessary feedback during inactive periods while maintaining reliability during active periods.

Inventive Principle:

Principle #35Parameter changes

2Productivity

If the terminal sends HARQ feedback during inactive periods of DTX/DRX, then feedback is transmitted, but energy efficiency is reduced

Engineering Contradiction:

Improveenergy efficiencyVSAvoidfeedback transmission timing

Core Design Contradiction:

ProductivityVSLoss of time

Solution Approach 1:

The patent applies periodic action by aligning HARQ feedback transmission with the periodic active periods of cell DTX/DRX. Instead of sending feedback continuously or at fixed intervals regardless of network state, the terminal synchronizes feedback transmission to coincide with active periods when the base station is actually transmitting, thereby improving energy efficiency without losing feedback timing effectiveness.

Inventive Principle:

Principle #19Periodic action

Data Source

PatentUS20260081725A1Hybrid automatic repeat request HARQ feedback method and apparatus, and terminal

Publication Date: 2026.03.19 VIVO MOBILE COMM CO LTD

AI summary

This application pertains to the field of communication technologies, and discloses a hybrid automatic repeat request HARQ feedback method and apparatus, and a terminal. The HARQ feedback method in embodiments of this application includes: determining, by a terminal based on first information, a HARQ feedback codebook to be sent based on a target physical uplink control channel PUCCH occasion, where the first information includes an inactive period of discontinuous transmission DTX in a target cell or discontinuous reception DRX in a target cell, and the target cell includes a serving cell of the terminal.