Merging HARQ Feedback for MTC PUCCH Resource Reduction

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Solution Overview

Problem

In Machine Type Communication (MTC) systems, the current hybrid automatic repeat request (HARQ) feedback mechanism consumes excessive PUCCH resources and delays feedback, leading to power inefficiency due to the need for individual acknowledgement/negative-acknowledgement (ACK/NACK) feedback for each physical downlink shared channel (PDSCH).

Innovation Solution

The method involves grouping HARQ results into sets and determining a combined HARQ result, which is then sent using a target PUCCH resource, optimizing resource usage and feedback timing to reduce power consumption and improve efficiency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If individual PUCCH resources are allocated for each PDSCH HARQ feedback, then feedback accuracy is improved, but PUCCH resource consumption increases and power efficiency deteriorates

Engineering Contradiction:
ImproveHARQ feedback accuracyVSAvoidpower consumption
Core Design Contradiction:
Measurement precisionVSUse of energy by moving object

Solution Approach 1:

The patent combines multiple HARQ feedback results into a single feedback message transmitted on one PUCCH resource. Instead of allocating separate PUCCH resources for each PDSCH acknowledgment, the method merges multiple ACK/NACK results into one consolidated feedback transmission, thereby reducing PUCCH resource consumption and power usage while maintaining feedback accuracy.

Inventive Principle:
Principle #5Merging (Combining)

2Loss of information

If individual PUCCH resources are allocated for each PDSCH HARQ feedback, then feedback completeness is improved, but feedback time delay increases

Engineering Contradiction:
Improvefeedback completenessVSAvoidfeedback time delay
Core Design Contradiction:
Loss of informationVSLoss of time

Solution Approach 1:

Multiple HARQ feedback results are merged into a single feedback transmission, which reduces the number of separate feedback transmissions required. This consolidation decreases feedback time delay while maintaining completeness by ensuring all HARQ results are included in the combined feedback message.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The patent performs preliminary grouping and combining of HARQ feedback results before transmission. By preparing the combined feedback message in advance and organizing multiple ACK/NACK results into a unified structure, the system reduces the time required for individual feedback transmissions while ensuring no information is lost.

Inventive Principle:
Principle #10Preliminary action

3Reliability

If multiple PUCCH resources are consumed for HARQ feedback, then feedback reliability is improved, but resource efficiency deteriorates

Engineering Contradiction:
Improvefeedback reliabilityVSAvoidPUCCH resource consumption
Core Design Contradiction:
ReliabilityVSQuantity of substance

Solution Approach 1:

The patent merges multiple HARQ feedback acknowledgments into a single PUCCH transmission, thereby reducing PUCCH resource consumption from multiple separate transmissions to one consolidated transmission. This approach maintains feedback reliability by ensuring all HARQ results are accurately transmitted in the combined message while significantly improving resource efficiency.

Inventive Principle:
Principle #5Merging (Combining)

Data Source

PatentEP3836442B1Hybrid automatic repeat request (HARQ) feedback method and apparatus
Publication Date: 2024.02.28 BEIJING XIAOMI MOBILE SOFTWARE CO LTD
  • EP3836442B1 patent drawingFigure 1
  • EP3836442B1 patent drawingFigure 2~3
  • EP3836442B1 patent drawingFigure 4

AI summary

The present invention provides a hybrid automatic repeat request (HARQ) feedback methods and apparatuses. A method includes: determining a plurality of target HARQ results; where the plurality of target HARQ results correspond to a plurality of respective target physical downlink shared channels (PDSCHs) which are scheduled by a current physical downlink control channel (PDCCH); determining a combined HARQ result based on the plurality of target HARQ results; where the combined HARQ result is configured to represent the plurality of target HARQ results; determining one target physical uplink control channel (PUCCH); where the target PUCCH includes a target resource carrying the combined HARQ result; and sending the target PUCCH that includes the target resource carrying the combined HARQ result to a base station. According to the present invention, it is possible to represent a plurality of target HARQ results by one combined HARQ result, so that HARQ feedback efficiency in an MTC system can be improved and cost of PUCCH resource can be reduced, which facilitate power saving for an MTC device.