Multi-Slot PDSCH HARQ Feedback Timing With Joint ACK Schemes

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Wireless communication systems face challenges in efficiently providing HARQ feedback for multiple PDSCH transmissions due to reduced timelines caused by higher subcarrier spacings in higher frequency ranges, leading to inefficient resource use, increased latency, and reduced network performance.

Innovation Solution

Implementing different HARQ feedback schemes, including using a single PUCCH resource, encoding schemes, and grouping PDSCHs for joint HARQ feedback, to optimize HARQ feedback for multiple PDSCHs scheduled by a single DCI, reducing interference and overhead.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If multiple PDSCHs are scheduled across multiple slots with dynamic timing, then resource utilization efficiency is improved, but HARQ feedback timing becomes ambiguous and unreliable

Engineering Contradiction:
Improveresource utilization efficiencyVSAvoidHARQ feedback timing
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The patent introduces an intermediary parameter (second time offset indicator) that mediates between the flexible PDSCH scheduling and the HARQ feedback timing mechanism. This intermediary allows the system to maintain dynamic resource allocation while providing a reliable reference point for determining when HARQ feedback should be transmitted, thus resolving the ambiguity caused by multi-slot scheduling.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent applies preliminary action by pre-configuring multiple possible time offset values in the time offset indicator table before transmission. The gNB selects appropriate offsets in advance based on the scheduling decision, and the UE retrieves the corresponding HARQ timing from the pre-established table, eliminating the need for complex real-time timing calculations and ensuring reliable feedback timing.

Inventive Principle:
Principle #10Preliminary action

2Quantity of substance

If a single HARQ-ACK codebook covers multiple PDSCHs, then feedback overhead is reduced, but the complexity of determining feedback timing increases

Engineering Contradiction:
Improvefeedback overheadVSAvoidfeedback timing determination
Core Design Contradiction:
Quantity of substanceVSDevice complexity

Solution Approach 1:

The patent uses copying by creating a structured mapping between PDSCH occasions and HARQ feedback opportunities through the time offset indicator table. Each entry in the table represents a copied template of timing relationships that can be applied to multiple PDSCHs, allowing the UE to determine feedback timing through simple table lookup rather than complex calculations, thus reducing device complexity while maintaining reduced feedback overhead.

Inventive Principle:
Principle #26Copying

3Productivity

If PDSCH reception occasions are distributed across multiple slots, then spectral efficiency is improved, but power consumption increases due to extended reception duration

Engineering Contradiction:
Improvespectral efficiencyVSAvoidpower consumption
Core Design Contradiction:
ProductivityVSUse of energy by moving object

Solution Approach 1:

The patent applies periodic action by organizing PDSCH reception occasions into periodic patterns with defined time offsets. The UE can anticipate reception slots based on the periodic structure and the configured time offset indicators, allowing it to enter low-power states between periodic reception occasions rather than continuously monitoring, thus reducing power consumption while maintaining improved spectral efficiency through multi-slot distribution.

Inventive Principle:
Principle #19Periodic action

Data Source

PatentEP4320770B1Improved hybrid automatic repeat request (HARQ) feedback for dynamic multi-slot physical downlink shared channel (PDSCH)
Publication Date: 2026.04.29 QUALCOMM INC
  • EP4320770B1 patent drawingFigure 1
  • EP4320770B1 patent drawingFigure 2
  • EP4320770B1 patent drawingFigure 3A~3D

AI summary

Techniques and apparatus for providing hybrid automatic repeat request (HARQ) feedback for multiple physical downlink shared channel (PDSCH) transmissions are described. One example technique involves receiving downlink control information (DCI) scheduling a plurality of downlink data transmissions across a plurality of slots. The plurality of downlink data transmissions are monitored across the plurality of slots. At least one HARQ feedback scheme for acknowledging the plurality of downlink data transmissions is determined. HARQ feedback for the plurality of downlink data transmissions is provided in accordance with the at least one HARQ feedback scheme.