Multicast HARQ-ACK Scheduling for PUCCH–PUSCH Timing Conflicts

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

There is a need for defined timelines and conditions for the transmission of acknowledgment information in wireless communication systems, particularly in managing conflicts between high and low priority channels in 5G mobile communication systems.

Innovation Solution

The method involves determining timelines and conditions for transmitting hybrid automatic repeat request (HARQ-ACK) information by scheduling physical uplink shared channels (PUSCH) and multicast physical downlink shared channels (PDSCHs), where overlapping transmissions are managed to ensure timely and appropriate HARQ-ACK information is transmitted.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If PUCCH transmission is used to provide HARQ-ACK information for multicast PDSCH receptions, then acknowledgment reliability is improved, but transmission timing conflicts arise when PUCCH overlaps with PUSCH

Engineering Contradiction:
ImproveHARQ-ACK information transmission reliabilityVSAvoidtransmission timing conflict
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The patent applies dynamics by making the HARQ-ACK transmission channel flexible and adaptive. The UE dynamically selects between PUCCH and PUSCH based on timing conditions: if the PUCCH transmission time does not overlap with PUSCH, use PUCCH; otherwise, multiplex HARQ-ACK in PUSCH. This dynamic channel selection resolves the timing conflict while maintaining reliability.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent uses PUSCH as an intermediary solution when PUCCH timing conflicts with PUSCH transmission. Instead of allowing the conflict to persist, the HARQ-ACK information is multiplexed into the PUSCH transmission, using the existing PUSCH resource as a mediator to carry the acknowledgment information without timing conflict.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Loss of time

If HARQ-ACK information is multiplexed in PUSCH, then transmission timing conflict is resolved, but information capacity of PUSCH is reduced

Engineering Contradiction:
Improvetransmission timing conflict resolutionVSAvoidinformation capacity of PUSCH
Core Design Contradiction:
Loss of timeVSQuantity of substance

Solution Approach 1:

The patent merges HARQ-ACK information with uplink data in the PUSCH transmission. By multiplexing the acknowledgment bits with the data payload, the system resolves the timing conflict while utilizing the existing PUSCH resource efficiently. The HARQ-ACK information is combined with the data transmission rather than requiring a separate channel.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The patent applies partial action by selectively multiplexing HARQ-ACK information in PUSCH only when necessary (i.e., when PUCCH timing overlaps with PUSCH). When no overlap occurs, the system uses dedicated PUCCH for HARQ-ACK transmission, preserving full PUSCH information capacity. This partial multiplexing approach minimizes the impact on PUSCH capacity.

Inventive Principle:
Principle #16Partial or excessive action

3Adaptability or versatility

If multiple PDCCHs scheduling multicast PDSCHs are received after the first PDCCH, then multicast communication coverage is improved, but determining which HARQ-ACK information to include in PUSCH becomes complex

Engineering Contradiction:
Improvemulticast communication coverageVSAvoidHARQ-ACK information selection complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent applies preliminary action by establishing clear selection criteria in advance for determining which HARQ-ACK information to include in PUSCH. The UE identifies a reference PDCCH among multiple received PDCCHs and includes HARQ-ACK information corresponding to PDSCHs scheduled by PDCCHs received before or at the same time as the reference PDCCH. This pre-defined rule set simplifies the decision process.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent enables the UE to autonomously determine which HARQ-ACK information to multiplex in PUSCH based on the reception timing of PDCCHs relative to the reference PDCCH. The UE self-services the complexity by independently applying the timing-based selection criterion without requiring additional network coordination or complex signaling.

Inventive Principle:
Principle #25Self-service

Data Source

PatentEP4381651B1Timelines and conditions for transmission of acknowledgment information
Publication Date: 2025.08.13 SAMSUNG ELECTRONICS CO LTD
  • EP4381651B1 patent drawingFigure 1
  • EP4381651B1 patent drawingFigure 2
  • EP4381651B1 patent drawingFigure 3

AI summary

The disclosure relates to a 5G or 6G communication system for supporting a higher data transmission rate. Methods and apparatuses for providing hybrid automatic repeat request acknowledgement (HARQ-ACK) information. A method includes receiving a first physical downlink control channel (PDCCH) that schedules a transmission of a physical uplink shared channel (PUSCH) in a slot and receiving PDCCHs that schedule receptions of first multicast physical downlink shared channels (PDSCHs), respectively. A first number of the PDCCHs is not received after the first PDCCH, and a second number of the PDCCHs is received after the first PDCCH. The method further includes determining that transmission of a PUCCH to provide the HARQ-ACK information associated with receptions of multicast PDSCHs, that include the first multicast PDSCHs, would overlap in time with the PUSCH transmission in the slot and transmitting the PUSCH. The PUSCH includes first HARQ-ACK information associated with the first number of PDCCHs and does not include second HARQ-ACK information associated with the second number of PDCCHs.