PDSCH Repetition QCL Mapping Across Multiple TRPs

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Solution Overview

Problem

The existing 3GPP NR Release 15 mechanism for PDSCH repetition is limited to transmissions from a single TRP or beam due to the restriction of having only one QCL information, which hinders the utilization of link diversity in coordinated multipoint scenarios, leading to suboptimal reliability in PDSCH transmissions.

Innovation Solution

The method involves informing the user equipment (UE) of multiple QCL information through transmission configuration indication (TCI) states, allowing PDSCH repetitions to be transmitted from multiple TRPs or beams, utilizing dynamic and semi-static signaling to configure the UE for receiving PDSCH information, and providing redundancy version, modulation order, and DMRS initialization parameters.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If only one QCL information is used for PDSCH repetition, then the transmission structure is simple, but all repetitions must be transmitted from the same TRP or beam, limiting link diversity

Engineering Contradiction:

Improvelink diversityVSAvoidQCL information configuration

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent segments the QCL information configuration by introducing multiple TCI states, each associated with different QCL information corresponding to different TRPs or beams. This allows the PDSCH repetition to be divided into multiple transmission segments from different TRPs, enabling link diversity while maintaining manageable configuration structure through systematic organization of TCI states.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent adds a new dimension to the transmission configuration by introducing TCI state indexing and pattern-based QCL information assignment. Instead of a single QCL configuration, the system now operates in a multi-dimensional configuration space where multiple TCI states can be selected and patterned across repetitions, enabling flexibility without proportional increase in complexity.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

2Reliability

If multiple TCI states are configured for PDSCH repetition, then multiple TRPs or beams can be used, but the configuration and signaling complexity increases

Engineering Contradiction:

ImprovePDSCH reliabilityVSAvoidTCI state configuration

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent makes the TCI state configuration universal by defining a standardized pattern-based approach that can accommodate multiple TRPs and beams through a single framework. The same TCI state pattern mechanism works for different numbers of repetitions and different TRP configurations, providing multi-functionality that reduces actual implementation complexity despite supporting multiple reliability-enhancing transmission paths.

Inventive Principle:

Principle #6Universality (Multi-functionality)

Solution Approach 2:

The patent uses parameter changes through TCI state patterns and indexing to manage complexity. Instead of configuring each QCL relationship individually, the system changes parameters such as pattern length, repetition count, and TCI state selection to achieve different reliability configurations, simplifying the overall setup while maintaining multiple TRP support.

Inventive Principle:

Principle #35Parameter changes

3Adaptability or versatility

If dynamic signaling is used for TCI states, then transmission flexibility is improved, but signaling overhead increases

Engineering Contradiction:

Improvetransmission flexibilityVSAvoidsignaling overhead

Core Design Contradiction:

Adaptability or versatilityVSLoss of information

Solution Approach 1:

The patent applies preliminary action by pre-configuring TCI states and their associated QCL information before the actual PDSCH transmission. The TCI states are prepared in advance and can be selected through simpler signaling mechanisms during transmission, reducing the need for complex dynamic reconfiguration and minimizing signaling overhead while maintaining transmission flexibility.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent uses copying by replicating TCI state configurations across multiple repetitions according to defined patterns. Instead of independently signaling each repetition's TRP assignment, the system copies and applies established TCI state patterns, reducing signaling redundancy while maintaining the flexibility to adapt to different transmission scenarios through pattern variation.

Inventive Principle:

Principle #26Copying

Data Source

PatentEP3804188B1Method and system for enhancing data channel reliability using multiple transmit receive points

Publication Date: 2025.12.17 HUAWEI TECH CO LTD

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AI summary

Devices and methods are provided for receiving a first indication and a second indication, the first indication associated with a first set of transmission parameter information for a first repetition of data received in a Physical Downlink Shared Channel (PDSCH) and the second indication associated with a second set of transmission parameter information for a second repetition of data received in the PDSCH. Each set of transmission parameter information corresponds to a Quasi-Co-Location (QCL) information for the respective repetition of data. In addition, the method involves receiving a first PDSCH repetition and a second PDSCH repetition. A channel estimate can then be performed for the first PDSCH repetition based on the QCL information for the first PDSCH repetition and a channel estimate for the second PDSCH repetition based on the QCL information for the second PDSCH repetition.