PUCCH HARQ-ACK Deferral for SPS Collision Handling

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Solution Overview

Problem

In wireless communication systems, particularly in 5G NR, there is a need to address the issue of hybrid automatic repeat request (HARQ) feedback dropping or deferral due to collisions on the physical uplink control channel (PUCCH), which can lead to inefficiencies and potential loss of valuable feedback information.

Innovation Solution

Implementing a HARQ ACK deferral component that determines whether to delay or cancel HARQ feedback based on a PUCCH collision, allowing the feedback to be transmitted on the first available PUCCH occasion, thereby optimizing the transmission of potentially useful feedback.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of information

If a UE transmits separate HARQ-ACK bits for each SPS PDSCH release and actual PDSCH reception, then HARQ-ACK information completeness is improved, but PUCCH resource usage and uplink overhead increase

Engineering Contradiction:
ImproveHARQ-ACK information completenessVSAvoidPUCCH resource usage
Core Design Contradiction:
Loss of informationVSQuantity of substance

Solution Approach 1:

The patent merges HARQ-ACK feedback for SPS PDSCH releases with HARQ-ACK feedback for actual PDSCH receptions into a single PUCCH transmission. The UE determines a combined PUCCH resource and transmits all HARQ-ACK bits together, reducing the number of separate PUCCH transmissions and optimizing uplink resource usage while maintaining complete HARQ-ACK information feedback.

Inventive Principle:
Principle #5Merging (Combining)

2Reliability

If the network configures multiple PUCCH resources for SPS PDSCH release, then HARQ-ACK feedback reliability is improved, but configuration complexity and signaling overhead increase

Engineering Contradiction:
ImproveHARQ-ACK feedback reliabilityVSAvoidPUCCH configuration complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent implements dynamic PUCCH resource selection where the UE determines the appropriate PUCCH resource based on the actual PDSCH reception status. When an actual PDSCH is received, the UE uses the PUCCH resource associated with that PDSCH for combined feedback. This dynamic approach maintains reliability by adapting to actual channel conditions while reducing configuration complexity compared to static multiple resource configuration.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent introduces a mapping relationship between PDSCH resources and PUCCH resources as an intermediary mechanism. This mapping table serves as a mediator that simplifies the configuration by providing a systematic way to associate downlink resources with uplink resources, reducing the need for explicit separate PUCCH configurations for each SPS release while maintaining feedback reliability.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Manufacturing precision

If the UE determines PUCCH resource based on SPS PDSCH release timing, then resource allocation accuracy is improved, but processing complexity and timing synchronization requirements increase

Engineering Contradiction:
ImprovePUCCH resource allocation accuracyVSAvoidTiming synchronization complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent applies preliminary action by pre-configuring the mapping relationship between SPS PDSCH releases and PUCCH resources before actual transmission occurs. The network provides the mapping table in advance, and the UE stores this mapping information for later use. This preliminary configuration simplifies real-time processing by eliminating the need for complex timing-based resource determination during actual HARQ-ACK feedback transmission.

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentEP4335056B1SPS pucch HARQ ACK/NACK configuration
Publication Date: 2026.04.29 QUALCOMM INC
  • EP4335056B1 patent drawingFigure 1
  • EP4335056B1 patent drawingFigure 2A~2D
  • EP4335056B1 patent drawingFigure 3

AI summary

A UE may receive, from a base station, at least one downlink packet or at least one downlink packet retransmission. The UE may determine that a transmission of a HARQ feedback associated with the at least one downlink packet or the at least one downlink packet retransmission corresponds to a PUCCH collision. The UE may determine, based on the determination that the transmission of the HARQ feedback corresponds to a PUCCH collision, whether to delay the transmission of the HARQ feedback associated with the at least one downlink packet or the at least one downlink packet retransmission to a first available PUCCH occasion. The UE may cancel or delay the transmission of the HARQ feedback to the base station based on the determination whether to delay the transmission of the HARQ feedback.