User Terminal MAC CE Segmentation for TCI State Control

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

In future radio communication systems like NR and 5G, user terminals struggle to properly control receiving processes for downlink control channels when configured with multiple CORESETs due to improper specification of TCI states using MAC CEs.

Innovation Solution

The solution involves configuring MAC CEs with specific fields that correspond to each CORESET, allowing the user terminal to identify and control the TCI states for each CORESET, ensuring proper reception of downlink control channels by including fields that show the quasi-co-location (QCL) information between the PDCCH or PDSCH and DL-RSs.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If TCI states are not specified properly using MAC CEs for multiple CORESETs, then the system complexity is reduced, but the user terminal cannot properly control receiving processes for downlink control channels

Engineering Contradiction:
Improvereceiving process controlVSAvoidMAC CE configuration
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The MAC CE is segmented into multiple fields, with each field corresponding to a specific CORESET. This segmentation allows the user terminal to properly control receiving processes for downlink control channels on a per-CORESET basis, resolving the reliability issue while maintaining manageable complexity through structured organization.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Each field in the MAC CE is configured with local quality specific to its corresponding CORESET, including TCI state information and QCL relationships. This localized configuration enables precise control of receiving processes for each CORESET without requiring complex global configuration, balancing reliability with device complexity.

Inventive Principle:
Principle #3Local quality

2Reliability

If MAC CEs are configured with fields for each CORESET to specify TCI states, then the user terminal can properly control receiving processes, but the MAC CE structure becomes more complex

Engineering Contradiction:
Improvedownlink control channel receptionVSAvoidMAC CE field structure
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The MAC CE is divided into multiple fields, with each field corresponding to a specific CORESET. This segmentation allows for proper specification of TCI states and QCL information on a per-CORESET basis, ensuring reliable downlink control channel reception while organizing the complexity into manageable, structured units.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The MAC CE structure is designed with multi-functionality, where each field can universally handle TCI state specification and QCL information for its corresponding CORESET. This universal approach allows the same MAC CE structure to serve multiple CORESETs with different configurations, reducing overall system complexity while maintaining reliability.

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

Data Source

PatentEP3739998B1User terminal and wireless communication method
Publication Date: 2024.03.06 NTT DOCOMO INC
  • EP3739998B1 patent drawingFigure 1
  • EP3739998B1 patent drawingFigure 2A~2C
  • EP3739998B1 patent drawingFigure 3A~3B

AI summary

According to the present disclosure, a user terminal has a receiving section that receives a MAC (Medium Access Control) control element, which includes one or more fields that respectively correspond to one or more control resource sets, and a control section that controls receipt of a downlink control channel, which is mapped to a given resource unit in the control resource sets, based on transmission configuration indicator (TCI) states of the control resource sets, shown in the fields.