User Terminal Uplink Control for Dual Connectivity

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Solution Overview

Problem

User terminals without support for simultaneous uplink transmission across multiple communication systems face challenges in performing communication effectively, particularly in dual connectivity scenarios, leading to potential communication failures.

Innovation Solution

Implementing a control mechanism in user terminals to prevent simultaneous uplink signal transmission across different communication systems by controlling the timing of uplink transmissions, allowing them to operate within the constraints of each system's configuration, such as using the transmission timing defined in the existing LTE system for FDD cells.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If a user terminal is configured to communicate with multiple communication systems simultaneously, then communication capacity and speed are improved, but the complexity of controlling uplink transmissions increases

Engineering Contradiction:
Improvecommunication capacityVSAvoidcontrol complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The patent segments the uplink transmission control by separating FDD and TDD transmission timing controls. The control section independently manages FDD cell uplink transmissions using FDD timing and TDD cell uplink transmissions using TDD timing, preventing simultaneous transmissions to different communication systems while maintaining overall communication capacity through structured segmentation of control functions.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The control section dynamically adjusts transmission timing based on the communication system configuration. When operating in dual connectivity mode with both FDD and TDD systems, the control section dynamically switches between FDD timing and TDD timing for different cell groups, enabling flexible adaptation to multiple communication systems without requiring simultaneous transmission capability.

Inventive Principle:
Principle #15Dynamics

2Reliability

If uplink transmission timing is controlled to avoid simultaneous transmissions, then communication reliability is improved, but transmission efficiency may be reduced

Engineering Contradiction:
Improvecommunication reliabilityVSAvoidtransmission efficiency
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The patent segments uplink transmission opportunities into distinct FDD and TDD time slots. By separating the transmission timing control for FDD cells and TDD cells, the system ensures reliable operation for terminals without simultaneous transmission capability while maximizing transmission efficiency within each segmented time period through proper scheduling of downlink allocations and uplink transmissions.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The control section performs preliminary scheduling of downlink transmissions in FDD and TDD cells before uplink transmissions occur. By preparing and scheduling downlink allocations in advance based on the segmented timing structure, the system ensures that uplink transmissions can be reliably controlled without simultaneous transmissions while maintaining high transmission efficiency through optimized scheduling.

Inventive Principle:
Principle #10Preliminary action

3Adaptability or versatility

If FDD and TDD transmission timings are independently controlled, then adaptability to different communication systems is improved, but the complexity of timing control increases

Engineering Contradiction:
Improvesystem adaptabilityVSAvoidtiming control complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The control section is segmented into distinct functional components that handle FDD and TDD timing independently. One component manages FDD cell uplink transmissions using FDD timing parameters, while another component manages TDD cell uplink transmissions using TDD timing parameters. This segmentation enables high adaptability to different communication systems while organizing complexity into manageable, independent functional blocks.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The control section implements a universal timing control mechanism that can handle both FDD and TDD transmission modes through a single integrated control unit. This universal controller adapts its behavior based on the communication system configuration, providing system adaptability while consolidating timing control complexity into one multi-functional control structure rather than separate independent controllers.

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

Data Source

PatentEP4171169A1User terminal, radio base station and radio communication method
Publication Date: 2023.04.26 NTT DOCOMO INC
  • EP4171169A1 patent drawingFigure 1
  • EP4171169A1 patent drawingFigure 2
  • EP4171169A1 patent drawingFigure 3

AI summary

In order to allow even a user terminal not supporting UL simultaneous communication to communicate appropriately in a future radio communication system, the present invention provides a user terminal communicating with a plurality of communication systems, having a reception section that receives a downlink (DL) signal transmitted from each of the communication system; a transmission section that transmits an uplink (UL) signal to each of the communication system; and a control section that controls reception of the DL signal and transmission of the UL signal. The control section controls not to transmit UL signals simultaneously to different communication systems.