Uplink HARQ-ACK Timing Under DTX and SPS PDSCH Scheduling

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Solution Overview

Problem

The challenge in wireless communication systems is to efficiently manage uplink control information transmission and reception, particularly for HARQ-ACK information, while implementing network energy saving (NES) to reduce power consumption.

Innovation Solution

A method and apparatus for transmitting and receiving HARQ-ACK information by defining inactive and active periods of Discontinuous Transmission (DTX) and activating semi-persistent scheduling (SPS) physical downlink shared channels (PDSCH), with specific rules for including or excluding HARQ-ACK information based on these periods.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Use of energy by moving object

If Discontinuous Transmission (DTX) is applied for network energy saving, then power consumption is reduced, but uplink control information transmission reliability deteriorates

Engineering Contradiction:
Improvepower consumptionVSAvoiduplink control information transmission reliability
Core Design Contradiction:
Use of energy by moving objectVSReliability

Solution Approach 1:

The invention segments the HARQ-ACK information transmission by dividing it into multiple PUCCH occasions. The UE transmits HARQ-ACK information in the first PUCCH occasion if the PDSCH reception occasion does not overlap with DTX active period, or in the second PUCCH occasion if it does overlap. This segmentation allows the system to maintain reliability by providing alternative transmission opportunities while respecting energy saving constraints.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The invention introduces dynamic adjustment of HARQ-ACK transmission timing based on the DTX active period configuration. The UE dynamically determines which PUCCH occasion to use for HARQ-ACK transmission by checking whether the PDSCH reception overlaps with the DTX active period. This dynamic behavior enables the system to adapt to changing energy saving requirements while maintaining reliable control information transmission.

Inventive Principle:
Principle #15Dynamics

2Reliability

If HARQ-ACK information is transmitted for all SPS PDSCHs, then acknowledgment completeness is improved, but uplink resource usage and interference increase

Engineering Contradiction:
Improveacknowledgment completenessVSAvoiduplink resource usage
Core Design Contradiction:
ReliabilityVSQuantity of substance

Solution Approach 1:

The invention extracts and removes unnecessary HARQ-ACK information from the uplink transmission. When the PDSCH reception occasion does not overlap with the DTX active period, the UE transmits HARQ-ACK only for PDSCHs received during inactive periods. This extraction principle eliminates redundant acknowledgments for PDSCHs that would not have been transmitted during active periods, thereby reducing uplink resource usage while maintaining acknowledgment completeness for actual data transmissions.

Inventive Principle:
Principle #2Taking out (Extraction)

Data Source

PatentEP4693977A1Method and apparatus for transmitting and receiving uplink control information in wireless communication system
Publication Date: 2026.02.11 LG ELECTRONICS INC
  • EP4693977A1 patent drawingFigure 1
  • EP4693977A1 patent drawingFigure 2
  • EP4693977A1 patent drawingFigure 3

AI summary

Disclosed are a method and apparatus for transmitting and receiving uplink control information in a wireless communication system. The method performed by a terminal in the wireless communication system, according to an embodiment of the present disclosure, may comprise the steps of: receiving first information about a first period where cell-related DTX is deactivated and a second period where the cell-related DTX is activated; receiving second information for activating transmission of one or more SPS PDSCHs; and transmitting HARQ-ACK information for the one or more SPS PDSCHs on the basis of the first information and the second information. Here, on the basis that a first SPS PDSCH is included in the second period, first HARQ-ACK information about the first SPS PDSCH may be included in the HARQ-ACK information, and on the basis that a second SPS PDSCH overlaps the first period, second HARQ-ACK information about the second SPS PDSCH may be excluded from the HARQ-ACK information.