Terminal Uplink Switching with Non-Switching Carrier Transmission

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Solution Overview

Problem

The uplink transmission switching function in wireless communication systems is rendered less effective when uplink signals are not transmitted during carrier switching periods, particularly in scenarios where non-target carriers are not transmitted during the switching period of another carrier.

Innovation Solution

A terminal is equipped with a transmission unit capable of performing band switching between multiple transmission chains and a reception unit for receiving control information, allowing it to transmit terminal capability information indicating whether it can transmit uplink signals during periods when switching is not occurring in another chain.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If uplink signal transmission is prohibited during carrier switching periods, then switching reliability is improved, but transmission productivity deteriorates

Engineering Contradiction:
Improveswitching reliabilityVSAvoidtransmission productivity
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The patent applies local quality by differentiating transmission permissions across different carriers during switching periods. Specifically, the terminal device is allowed to transmit uplink signals on non-target carriers (carriers not involved in switching) while prohibiting transmission only on target carriers (carriers undergoing switching). This localized differentiation resolves the contradiction by maintaining switching reliability on target carriers while preserving transmission productivity on non-target carriers.

Inventive Principle:
Principle #3Local quality

2Adaptability or versatility

If the number of configured carriers is increased from two to four, then system adaptability is improved, but device complexity increases

Engineering Contradiction:
Improvesystem adaptabilityVSAvoiddevice complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent applies segmentation by dividing the four configured carriers into two distinct groups: target carriers (subject to switching) and non-target carriers (not subject to switching). This segmentation allows the terminal to independently manage transmission permissions for each group, enabling support for more carriers without proportionally increasing complexity. The segmentation strategy reduces the burden on the terminal by providing clear, differentiated transmission rules for different carrier types.

Inventive Principle:
Principle #1Segmentation

Data Source

PatentEP4618665A1Terminal, base station, and communication method
Publication Date: 2025.09.17 NTT DOCOMO INC
  • EP4618665A1 patent drawingFigure 1~2
  • EP4618665A1 patent drawingFigure 3
  • EP4618665A1 patent drawingFigure 4

AI summary

A terminal includes: a transmission unit configured to transmit an uplink signal by using a switching method in which band switching between a plurality of transmission chains can be performed; and a reception unit configured to receive control information indicating a band switching destination of one of the plurality of transmission chains used for transmitting the uplink signal. In a case where transmission switching is being performed for one transmission chain of the plurality of transmission chains while transmission switching is not being performed for another transmission chain, the transmission unit transmits, to a base station, terminal capability information indicating whether or not an uplink signal can be transmitted by using a transmission chain for which transmission switching is not being performed.