Variable TTI Terminal Device for LTE Transmission Efficiency

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Solution Overview

Problem

In LTE communication systems, the fixed 1 millisecond transmission time interval (TTI) limits data transmission efficiency, particularly when multiple physical resources are consecutively allocated, leading to deteriorated system transmission efficiency.

Innovation Solution

The introduction of a wireless communication system with a radio frame configuration of 10 ms, comprising two half frames, each with 5 sub frames, allows for flexible allocation of downlink and uplink sub frames, enabling improved data transmission efficiency by optimizing the timing of physical channel and signal transmission.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If a fixed 1 millisecond TTI is used for data transmission, then the transmission timing is standardized and simple to manage, but the system transmission efficiency deteriorates when multiple physical resources are consecutively allocated

Engineering Contradiction:
Improvesystem transmission efficiencyVSAvoidtransmission timing management complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The patent applies dynamics by making the TTI duration variable rather than fixed. The base station determines the TTI duration dynamically based on the terminal's movement state (moving or stationary) and allocates physical resources accordingly. For moving terminals, longer TTI durations are used to maintain connection stability, while for stationary terminals, shorter TTI durations improve transmission efficiency. This dynamic adjustment resolves the contradiction between transmission efficiency and management complexity.

Inventive Principle:
Principle #15Dynamics

2Loss of time

If multiple physical resources are consecutively allocated to reduce data transmission time, then the latency is reduced, but the system transmission efficiency greatly deteriorates

Engineering Contradiction:
Improvedata transmission latencyVSAvoidsystem transmission efficiency
Core Design Contradiction:
Loss of timeVSProductivity

Solution Approach 1:

The patent changes the TTI duration parameter based on terminal movement state. By adjusting the TTI duration parameter dynamically, the system optimizes the balance between transmission latency and overall transmission efficiency. The base station determines appropriate TTI durations and informs terminals, allowing flexible resource allocation that adapts to different terminal states rather than using fixed resource allocation patterns.

Inventive Principle:
Principle #35Parameter changes

3Reliability

If the TTI duration is extended for moving terminals to maintain connection stability, then the connection reliability improves, but the transmission efficiency for stationary terminals deteriorates

Engineering Contradiction:
Improveconnection stability for moving terminalsVSAvoidtransmission efficiency for stationary terminals
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The patent applies local quality by customizing the TTI duration according to each terminal's specific movement state. Moving terminals receive longer TTI durations to ensure connection stability, while stationary terminals receive shorter TTI durations to maximize transmission efficiency. This localized optimization based on terminal-specific conditions resolves the contradiction between reliability and efficiency for different terminal types.

Inventive Principle:
Principle #3Local quality

Data Source

PatentEP3439395B1Terminal device, base station and communication method
Publication Date: 2021.10.27 SONY GROUP CORP
  • EP3439395B1 patent drawingFigure 1
  • EP3439395B1 patent drawingFigure 2
  • EP3439395B1 patent drawingFigure 3

AI summary

[Object] To provide a terminal device capable of efficiently performing communication in a communication system in which a base station device and the terminal device communicate with each other. [Solution] A terminal device that communicates with a base station device includes: a receiving unit configured to receive a first PDSCH that is transmitted on a basis of a sub frame which is defined by a predetermined number of symbols, and a second PDSCH that is transmitted on a basis of an extended sub frame which has a smaller number of symbols than a number of symbols corresponding to the sub frame; and a transmitting unit configured to transmit a first HARQ-ACK that is a feedback for reception of the first PDSCH after a predetermined sub frame, and transmit a second HARQ-ACK that is a feedback for reception of the second PDSCH after a predetermined extended sub frame.