Short TTI Pattern Signaling for LTE Downlink Efficiency

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Solution Overview

Problem

The use of short Transmission Time Interval (sTTI) in LTE and LTE-A communication systems has not been sufficiently studied, leading to inefficiencies in communication processes.

Innovation Solution

The implementation of terminal and base station apparatus configurations that enable efficient communication using sTTI, including specific configurations for physical channels and signals, such as sPDCCH and sPDSCH, and the use of sTTI pattern information to determine transmission schemes for sPDCCH and sPDSCH, allowing for efficient downlink data transmission.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Speed

If sTTI is introduced to reduce packet delay, then communication speed is improved, but system complexity increases due to insufficient study and lack of standardized configurations

Engineering Contradiction:

Improvecommunication speedVSAvoidsystem complexity

Core Design Contradiction:

SpeedVSDevice complexity

Solution Approach 1:

The patent applies parameter changes by modifying TTI duration from traditional 1ms to shorter durations (2ms, 1ms, or 0.5ms), and by changing the structure of physical channels (sPDCCH, sPDSCH) to accommodate the shortened time interval. This enables faster communication while maintaining systematic control through standardized parameter definitions.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent segments the traditional TTI structure into shorter, more granular time intervals (sTTI). By dividing the transmission time into smaller units, the system achieves faster packet delivery and reduced delay while allowing flexible configuration of different sTTI lengths to balance speed and complexity requirements.

Inventive Principle:

Principle #1Segmentation

2Productivity

If sTTI pattern information is used to determine transmission schemes, then downlink resource utilization is optimized, but terminal apparatus complexity increases

Engineering Contradiction:

Improvedownlink resource utilizationVSAvoidterminal apparatus complexity

Core Design Contradiction:

ProductivityVSDevice complexity

Solution Approach 1:

The patent applies preliminary action by pre-configuring sTTI pattern information and transmission schemes before actual data transmission. The base station determines and signals the sTTI pattern (including length, position, and resource allocation) in advance, allowing the terminal to efficiently process downlink resources without real-time decision complexity.

Inventive Principle:

Principle #10Preliminary action

3Adaptability or versatility

If legacy TTI and short TTI are multiplexed, then backward compatibility is maintained, but blind decoding amount increases

Engineering Contradiction:

Improvebackward compatibilityVSAvoidblind decoding time

Core Design Contradiction:

Adaptability or versatilityVSLoss of time

Solution Approach 1:

The patent extracts and separates the control mechanisms for legacy TTI and sTTI into distinct configurations. By using separate sTTI pattern information and transmission scheme determinations for short TTI operations, the system maintains backward compatibility with legacy TTIs while reducing blind decoding requirements through dedicated sTTI resource signaling.

Inventive Principle:

Principle #2Taking out (Extraction)

Data Source

PatentEP3457806B1Efficient communications using a short tti

Publication Date: 2023.03.29 SHARP KK

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AI summary

A terminal apparatus includes a higher layer processing unit configured to configure transmission mode information; and a reception unit configured to receive a physical downlink shared channel and a short physical downlink shared channel, and the transmission mode information indicates a transmission mode for the physical downlink shared channel and a transmission mode for the short physical downlink shared channel.