Terminal Device Power Control for DTDD Interference

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Solution Overview

Problem

In communication systems employing dynamic time-division duplexing (DTDD), the interference between signals transmitted by base station devices and terminal devices in subframes that can switch between uplink and downlink configurations hinders appropriate communication.

Innovation Solution

A terminal device is equipped with the capability to conduct appropriate transmitted power control, allowing it to manage power settings based on specific configurations and commands received from the base station device, thereby minimizing interference.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If dynamic time-division duplexing (DTDD) is implemented to flexibly switch between uplink and downlink subframes, then communication efficiency and adaptability are improved, but signal interference between base station and terminal devices occurs in switching subframes

Engineering Contradiction:
Improvecommunication efficiencyVSAvoidsignal interference
Core Design Contradiction:
ProductivityVSObject-generated harmful factors

Solution Approach 1:

The base station device transmits a cancellation indicator in advance before the actual cancellation action. This preliminary indication allows the terminal device to prepare for the upcoming power cancellation, preventing interference before it occurs. The cancellation indicator is sent in a downlink subframe, and the terminal device cancels the uplink signal transmission in the subsequently switched uplink subframe, ensuring no interference is generated.

Inventive Principle:
Principle #9Preliminary anti-action

Solution Approach 2:

The system performs preliminary configuration of cancellation indicators and their timing relationships before actual DTDD switching occurs. The base station configures which downlink subframes may contain cancellation indicators and which uplink subframes may be cancelled, establishing the framework for interference-free switching in advance.

Inventive Principle:
Principle #10Preliminary action

2Reliability

If power control is implemented to reduce signal interference in DTDD systems, then communication quality is improved, but device complexity increases due to additional control mechanisms

Engineering Contradiction:
Improvecommunication qualityVSAvoidcontrol mechanism complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The invention extracts the power control function into a separate, dedicated mechanism. Instead of embedding complex power control logic within the general DTDD switching control, the base station uses a specific cancellation indicator field in downlink control information to solely manage uplink power cancellation. This separation simplifies the overall control architecture while maintaining reliable interference management.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The cancellation indicator acts as an intermediary between the base station's switching decision and the terminal's power control action. Rather than the terminal directly responding to complex switching commands, the intermediary indicator simplifies the terminal's task to a clear binary decision: cancel or continue transmission based on the received indicator.

Inventive Principle:
Principle #24Intermediary (Mediator)

Data Source

PatentEP2996415B1Terminal device, communication method, and integrated circuit
Publication Date: 2019.09.04 SHARP KK
  • EP2996415B1 patent drawingFigure 1
  • EP2996415B1 patent drawingFigure 2
  • EP2996415B1 patent drawingFigure 3

AI summary

Provided is a terminal device (2) that communicates with a base station device, including: a reception unit (205) that receives information related to a first configuration and/or information related to a second configuration, and a grant; and a transmission unit (207) that, in a case of an uplink signal being scheduled based on the grant, transmits the uplink signal to the base station device in an earliest uplink subframe on or after a designated subframe from a subframe in which the grant was detected, wherein in a case of the first configuration and the second configuration being set, the transmission unit (207) configures a transmit power control method for respective subframe subsets according to the type of grant.