HARQ-ACK Feedback Positioning for Low-Latency PDSCH Transmission

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Solution Overview

Problem

The existing technologies face challenges in reducing the delay of Hybrid Automatic Repeat Request Acknowledgment (HARQ-ACK) feedback, particularly in Hybrid Automatic Repeat Request Acknowledgment (HARQ-ACK) codebooks corresponding to Physical Downlink Shared Channels (PDSCH), limiting the timely transmission of HARQ-ACK feedback.

Innovation Solution

The method involves setting the position for HARQ-ACK transmission by a first communication node and enabling a second communication node to feedback HARQ-ACK corresponding to a Physical Downlink Shared Channel (PDSCH) in time, using parameters such as DCI, CRC bit generator polynomials, RNTI sequence scramblers, or PRI values to determine the appropriate PUCCH for HARQ-ACK transmission, allowing multiple transmission opportunities within an uplink unit.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of time

If the HARQ-ACK feedback mechanism uses a limited transmission chance per uplink unit, then the system maintains simpler resource allocation, but the HARQ-ACK feedback delay increases

Engineering Contradiction:
ImproveHARQ-ACK feedback delayVSAvoidresource allocation complexity
Core Design Contradiction:
Loss of timeVSDevice complexity

Solution Approach 1:

The patent introduces dynamic HARQ-ACK transmission opportunities within an uplink unit by utilizing different PUCCH resource types (first type and second type). The system dynamically selects which PUCCH resource to use based on scheduling conditions, allowing multiple transmission chances within the same uplink unit. This dynamic approach reduces feedback delay while maintaining manageable resource allocation through structured resource types.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent segments the PUCCH resources into different types (first type PUCCH and second type PUCCH) with distinct characteristics and usage scenarios. By dividing the resource allocation into segmented types, the system enables multiple transmission opportunities without creating fully complex resource management. Each PUCCH type has specific rules for when it should be used, simplifying the overall allocation complexity while increasing transmission flexibility.

Inventive Principle:
Principle #1Segmentation

2Loss of time

If multiple PUCCH resources are configured for HARQ-ACK transmission, then the feedback latency is reduced, but the signaling overhead increases

Engineering Contradiction:
Improvefeedback latencyVSAvoidsignaling overhead
Core Design Contradiction:
Loss of timeVSLoss of information

Solution Approach 1:

The patent uses parameter changes in the DCI format (specifically the PUCCH resource indication field values) to indicate which PUCCH resource type should be used. By encoding resource selection information in existing DCI parameters rather than adding new signaling fields, the system enables multiple transmission opportunities while minimizing additional signaling overhead. The parameter values directly map to predefined PUCCH resource configurations.

Inventive Principle:
Principle #35Parameter changes

3Productivity

If the HARQ-ACK codebook size is based on configured CCs rather than scheduled CCs, then the resource allocation is simpler, but the feedback efficiency decreases

Engineering Contradiction:
Improvefeedback efficiencyVSAvoidcodebook management complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The patent prepares multiple PUCCH resources in advance (both first type and second type resources) with different characteristics and capacities. These pre-configured resources are ready to be selected based on the actual scheduling conditions. This preliminary preparation allows the system to efficiently handle variable codebook sizes without complex real-time allocation decisions, improving feedback efficiency while maintaining manageable complexity through pre-planned resource configurations.

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentEP3876453B1Information transmission method and apparatus
Publication Date: 2026.02.18 ZTE CORP
  • EP3876453B1 patent drawingFigure 1~2
  • EP3876453B1 patent drawingFigure 3~5
  • EP3876453B1 patent drawingFigure 6~7

AI summary

The disclosure provides an information transmission method and apparatus. The method includes: carrying a first parameter in physical layer signaling corresponding to a Physical Downlink Shared Channel (PDSCH); and transmitting, according to an indication of the first parameter, a Hybrid Automatic Repeat Request Acknowledgment (HARQ-ACK) corresponding to the PDSCH, which may be specifically identifying an indication meaning of the current first parameter on a predetermined basis and selecting which positions are used to transmit the HARQ-ACK. By adopting the above solution, a first communication node itself sets a position at which an HARQ-ACK is transmitted, and a second communication node feeds back, according to an indication, the HARQ-ACK corresponding to a PDSCH in time, thereby solving the problem of greater delay for HARQ-ACK feedback in the related art, and ensuring the low delay processing of a service.