GC-PDCCH NNK1 Feedback Holding for MBMS Resource Conflicts

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Solution Overview

Problem

Current MBMS systems face challenges in efficiently managing feedback reporting for group common-physical downlink shared channel (GC-PDSCH) transmissions due to interference and resource conflicts, particularly when using non-numerical K1 (NNK1) indications in GC-PDCCH transmission grants, leading to increased control overhead and potential transmission failures.

Innovation Solution

Implementing NNK1 indications in GC-PDCCH transmission grants for UEs to hold feedback codebooks until a report triggering event occurs, allowing UEs to determine valid K1 values for PUCCH resource transmission, thereby optimizing feedback reporting and reducing conflicts.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If NNK1 indications are used in GC-PDCCH transmission grants to allow flexible feedback reporting, then adaptability is improved, but control overhead increases

Engineering Contradiction:
Improvefeedback reporting flexibilityVSAvoidcontrol overhead
Core Design Contradiction:
Adaptability or versatilityVSQuantity of substance

Solution Approach 1:

The patent changes the parameter representation from numerical K1 values to non-numerical K1 (NNK1) indications. Instead of specifying exact timing offsets, the system uses indicator values that map to predetermined timing relationships, allowing flexible feedback reporting while reducing control message complexity and overhead.

Inventive Principle:
Principle #35Parameter changes

2Adaptability or versatility

If NNK1 indications are used to manage feedback timing, then adaptability is improved, but transmission reliability deteriorates due to resource conflicts

Engineering Contradiction:
Improvefeedback timing controlVSAvoidtransmission reliability
Core Design Contradiction:
Adaptability or versatilityVSReliability

Solution Approach 1:

The system performs preliminary configuration by establishing predetermined mappings between NNK1 indicator values and feedback timing relationships before actual transmission occurs. This pre-planned structure prevents resource conflicts by ensuring that feedback reports are scheduled in advance without overlapping, thereby maintaining high transmission reliability while preserving timing flexibility.

Inventive Principle:
Principle #10Preliminary action

3Object-generated harmful factors

If feedback reporting is held until report triggering events, then resource conflicts are reduced, but loss of time increases due to delayed feedback

Engineering Contradiction:
Improveresource conflictsVSAvoidfeedback delay
Core Design Contradiction:
Object-generated harmful factorsVSLoss of time

Solution Approach 1:

The system implements periodic feedback reporting triggered by specific events rather than continuous or fixed periodic reporting. Feedback is held until predetermined triggering events occur, such as receiving a specific downlink transmission or reaching a configured timing threshold. This event-driven approach reduces resource conflicts by synchronizing feedback reports with natural transmission boundaries while limiting delays through configured triggering conditions.

Inventive Principle:
Principle #19Periodic action

Data Source

PatentEP4226536B1Non-numerical k1 for group common-physical downlink control channel (GC-pdcch) grant in multimedia broadcast multicast service (MBMS)
Publication Date: 2026.01.28 QUALCOMM INC
  • EP4226536B1 patent drawingFigure 1
  • EP4226536B1 patent drawingFigure 2
  • EP4226536B1 patent drawingFigure 3

AI summary

This disclosure provides systems, methods, and devices for wireless communication that support control of feedback reporting associated with broadcast or multicast transmissions based on indications of non-numerical K1 (NNK1) in associated transmission grants. In aspects, a base station transmits multicast transmission grants that include NNK1s to a set of UEs. The UEs in the set of UEs generate feedback codebooks, for the multicast transmissions, and holds transmission of the codebooks, based on the NNK1 received in the transmission grants until a report triggering event occurs. In aspects, the report triggering event includes receiving a subsequent multicast transmission grant with a valid K1, receiving a subsequent unicast transmission grant with valid K1, or receiving a UE-specific multicast retransmission grant. In aspects, the UEs use the valid K1 in the triggering event to determine a feedback resource to transmit the held feedback codebooks. Other aspects and features are also claimed and described.