GC-PDCCH Grants for MBMS Feedback Codebook Alignment

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Solution Overview

Problem

Current wireless communication systems face a feedback codebook misalignment issue due to the use of multiple feedback timing indicators (K1s) in group common-physical downlink control channel (GC-PDCCH) transmission grants, leading to varying sizes of feedback codebooks reported by different user equipment (UEs) in the physical uplink control channel (PUCCH) occasion.

Innovation Solution

The proposed solution involves transmitting GC-PDCCH transmission grants that include a common K1 and multiple PUCCH resource indicators (PRIs) to ensure that UEs report feedback codebooks of the same size, either by configuring scheduling restrictions or using relative K1s to determine feedback resources, allowing for synchronized feedback reporting across UEs.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If multiple feedback timing indicators (K1s) are used in GC-PDCCH transmission grants to allow flexible feedback timing for different UEs, then adaptability of feedback scheduling is improved, but feedback codebook size alignment deteriorates causing misalignment issues

Engineering Contradiction:
Improvefeedback scheduling flexibilityVSAvoidfeedback codebook size alignment
Core Design Contradiction:
Adaptability or versatilityVSManufacturing precision

Solution Approach 1:

The patent segments the feedback timing indication into two parts: a common K1 value that applies to all UEs for codebook size alignment, and UE-specific PUCCH resource indicators (PRIs) that provide individualized feedback resources. This segmentation allows the system to maintain both codebook alignment and scheduling flexibility simultaneously.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent applies local quality by making the K1 parameter uniform (common quality) across all UEs to ensure codebook alignment, while allowing the PUCCH resource indicators to be locally customized for each UE. This enables different parts of the feedback mechanism to have different properties: common K1 for alignment, UE-specific PRIs for flexibility.

Inventive Principle:
Principle #3Local quality

2Ease of operation

If multiple PUCCH resource indicators (PRIs) are configured for different UEs to enable individualized feedback resources, then ease of operation is improved, but control overhead increases

Engineering Contradiction:
Improveindividualized feedback resource allocationVSAvoidcontrol signaling overhead
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The patent makes the common K1 parameter universal across all UEs, serving multiple functions: it provides feedback timing information to all UEs simultaneously and ensures codebook size alignment. This universality reduces the need for separate K1 indications for each UE, thereby reducing control overhead while maintaining individualized resource allocation through PRIs.

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

3Adaptability or versatility

If feedback codebooks of varying sizes are reported by different UEs, then adaptability to different UE conditions is improved, but reliability of feedback processing deteriorates due to misalignment

Engineering Contradiction:
ImproveUE-specific feedback adaptationVSAvoidfeedback codebook alignment
Core Design Contradiction:
Adaptability or versatilityVSReliability

Solution Approach 1:

The patent creates equipotentiality in the feedback codebook size across all UEs by using a common K1 value. This ensures that all UEs generate feedback codebooks of the same size, making them comparable and reliably processable. Meanwhile, UE-specific PRIs allow individualized resource allocation to maintain adaptability to different UE conditions.

Inventive Principle:
Principle #12Equipotentiality

Data Source

PatentEP4226542B1Multiple feedback control for group common-physical downlink shared channel (GC-pdsch) in multimedia broadcast multicast service (MBMS)
Publication Date: 2024.09.04 QUALCOMM INC
  • EP4226542B1 patent drawingFigure 1
  • EP4226542B1 patent drawingFigure 2
  • EP4226542B1 patent drawingFigure 3

AI summary

This disclosure provides systems, methods, and apparatuses, including computer programs encoded on computer storage media, for enabling a wireless system implementing multicast transmissions to control feedback reports from multiple user equipments (UEs) and to address feedback codebook misalignment issues. In particular, aspects provide for multicast transmission grants including multiple feedback timing indicators (K1) in which the multicast transmission grants are configured to configure different UEs for multicast transmission feedback reporting in which feedback codebooks transmitted in various uplink control transmission occasions from the different UEs have a same size. Other aspects and features are also claimed and described.