HARQ Feedback Timing for Multi-Carrier PDSCH Scheduling

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Solution Overview

Problem

Existing wireless communication systems face challenges in efficiently managing hybrid automatic repeat request (HARQ) feedback for multiple physical downlink shared channels (PDSCH) scheduled via cross component carriers, leading to issues with coverage, reliability, and flexibility in 5G systems.

Innovation Solution

Configuring user equipment (UE) to provide HARQ feedback for multiple PDSCHs across different component carriers, allowing for improved coverage and flexibility by determining appropriate slots for feedback transmission based on subcarrier spacing and time domain resource allocation fields in DCI messages.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If multiple component carriers are scheduled using multiple DCIs, then scheduling flexibility and resource allocation efficiency are improved, but downlink control information overhead and processing complexity increase

Engineering Contradiction:
Improvescheduling efficiencyVSAvoiddownlink control information overhead
Core Design Contradiction:
ProductivityVSQuantity of substance

Solution Approach 1:

The patent combines multiple DCIs into a single unified DCI structure that schedules multiple component carriers simultaneously. This merging approach maintains the scheduling flexibility of multiple DCIs while reducing the overall control information overhead by eliminating redundant fields and utilizing shared resources across carriers.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The unified DCI structure is designed to serve multiple component carriers with a single message, making the control information multi-functional. This universal approach allows one DCI to perform the scheduling function for multiple carriers, thereby reducing the quantity of control information while maintaining comprehensive scheduling capability.

Inventive Principle:
Principle #6Universality (Multi-functionality)

2Manufacturing precision

If multiple DCIs are transmitted for multi-component carrier scheduling, then resource allocation precision is improved, but device processing complexity and power consumption increase

Engineering Contradiction:
Improveresource allocation precisionVSAvoidprocessing complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent merges multiple resource allocation indications into a unified DCI structure with shared fields. This combination maintains precise resource allocation for each component carrier while reducing the total number of fields that need to be processed, thereby lowering device processing complexity.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The unified DCI structure implements local quality by allowing carrier-specific resource allocation parameters while maintaining shared common fields. This approach enables precise local resource allocation for each component carrier without requiring complete duplication of control information, thus balancing precision with processing complexity.

Inventive Principle:
Principle #3Local quality

3Adaptability or versatility

If separate DCIs are used for each component carrier, then scheduling adaptability is improved, but feedback overhead and acknowledgment complexity increase

Engineering Contradiction:
Improvescheduling adaptabilityVSAvoidfeedback overhead
Core Design Contradiction:
Adaptability or versatilityVSQuantity of substance

Solution Approach 1:

The patent merges acknowledgment feedback for multiple component carriers into a single unified feedback message. This combining approach maintains the adaptability of individual carrier scheduling while reducing feedback overhead by eliminating redundant acknowledgment fields and enabling shared feedback resources across multiple carriers.

Inventive Principle:
Principle #5Merging (Combining)

Data Source

PatentEP4107886B1Acknowledgement feedback for multi-component carrier scheduling
Publication Date: 2026.04.29 QUALCOMM INC
  • EP4107886B1 patent drawingFigure 1
  • EP4107886B1 patent drawingFigure 2
  • EP4107886B1 patent drawingFigure 3

AI summary

Methods, systems, and devices for wireless communications are described. A user equipment (UE) to provide hybrid automatic repeat request (HARQ) feedback for multiple physical channels (e.g., multiple physical downlink shared channels (PDSCH)) scheduled via cross component carrier. The UE may monitor control channel occasions, to receive wireless communications from a base station. For example, the UE may receive downlink control information (DCI) messages that may schedule multiple PDSCH over different component carriers. The DCI messages may include an indication of a timing offset for HARQ feedback for the multiple PDSCH. In some examples, the UE may be configured to receive multiple DCI messages and order the DCI messages based on component carrier indices or a PDCCH occasion, or both. The UE may then determine a slot to transmit HARQ feedback for the multiple PDSCH based on an indication in a latest DCI message identified according to the ordering.