Terminal QCL Scheduling for Multicast Downlink Reception

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Solution Overview

Problem

In future wireless communication systems like NR, the reception of multicast downlink data by multiple user terminals in ultra-dense and high-traffic environments is not adequately addressed, leading to potential system performance deterioration such as decreased throughput.

Innovation Solution

Implementing a group scheduling mechanism that associates reception occasions with quasi-co-location (QCL) assumptions and resource configurations to optimize the reception of multicast downlink data, using techniques like TCI states and QCL types to manage beamforming and resource allocation for multiple user equipment (UEs).

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If conventional NR specifications are used for multicast downlink data reception, then the system can operate with existing protocols, but system performance deteriorates with decreased throughput in ultra-dense and high-traffic environments

Engineering Contradiction:
ImprovethroughputVSAvoidmulticast reception performance
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The patent segments the multicast reception process by introducing group-specific configuration parameters and separating the scheduling mechanism into group-based resources. This allows different QCL assumptions and TCI states to be assigned to different UE groups, enabling optimized reception for each group while maintaining overall system throughput.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent implements dynamic adaptation by allowing the network to configure and update group scheduling parameters, QCL assumptions, and TCI states based on real-time channel conditions and traffic patterns. This dynamic configuration enables the system to optimize multicast reception performance in response to changing environmental conditions in ultra-dense networks.

Inventive Principle:
Principle #15Dynamics

2Reliability

If group scheduling with multiple QCL assumptions is implemented, then multicast reception is optimized, but device complexity increases for managing multiple TCI states and reception occasions

Engineering Contradiction:
Improvemulticast reception performanceVSAvoidUE configuration management
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent creates universal group scheduling mechanisms that can be applied across multiple UE groups with different configurations. The group-common PDCCH and group-specific PDSCH structure provides a multi-functional framework that handles both unicast and multicast traffic while managing QCL assumptions and TCI states through standardized procedures, reducing the complexity burden on individual UEs.

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

Solution Approach 2:

The patent enables UEs to self-configure their reception parameters by providing group-specific configuration information through broadcast or group-common signaling. Each UE in a group can automatically apply the configured QCL assumptions and TCI states without requiring individual manual configuration, reducing the operational complexity for users while maintaining optimized reception performance.

Inventive Principle:
Principle #25Self-service

Data Source

PatentEP4132145B1Terminal, wireless communication method, and base station
Publication Date: 2026.03.25 NTT DOCOMO INC
  • EP4132145B1 patent drawingFigure 1
  • EP4132145B1 patent drawingFigure 2A~2B
  • EP4132145B1 patent drawingFigure 3

AI summary

A terminal according to an aspect of the present disclosure includes a receiving section that receives downlink control information, and a control section that uses, among a plurality of reception occasions, a reception occasion corresponding to a quasi-co-location (QCL) parameter for receiving data, in which the downlink control information schedules the plurality of reception occasions, and the data is transmitted in each of the plurality of the reception occasions. According to one aspect of the present disclosure, multicast downlink data can be appropriately received.