Dynamic TTI Selection for LTE Data Transmission
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Solution Overview
Problem
Current communication technologies face challenges in reducing transmission delay, particularly in LTE systems, where shortening the Transmission Time Interval (TTI) to improve delay reduces spectral efficiency and leads to resource wastage and compatibility issues with existing systems.
Innovation Solution
A method and terminal that dynamically select and use multiple Transmission Time Intervals (TTIs) for different Physical Downlink Shared Channels (PDSCH) and Physical Uplink Shared Channels (PUSCH) on the same carrier, based on configuration information and DCI presence, to optimize resource utilization and reduce delay.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of time
If a uniform TTI is determined for a terminal simultaneously having various services, then the delay requirement of services with minimum delay requirement is met, but resources are wasted
Solution Approach 1:
The patent implements dynamic TTI selection where the terminal can switch between long TTI (1ms) and short TTI (2ms or 0.5ms) based on service requirements. The base station configures multiple TTI lengths and the terminal dynamically selects appropriate TTI for different services, allowing resources to be efficiently allocated according to actual needs rather than using a uniform TTI for all services.
2Loss of time
If short TTI is used to reduce transmission delay, then the delay is reduced, but spectral efficiency decreases and compatibility with existing LTE system cannot be ensured
Solution Approach 1:
The patent segments the TTI into multiple length options (1ms, 2ms, 0.5ms) that can be selectively applied to different services or data transmissions. This segmentation allows the system to use short TTI (0.5ms) for delay-sensitive services to reduce transmission delay, while using longer TTI (1ms or 2ms) for other services to maintain spectral efficiency and ensure compatibility with existing LTE systems.
3Loss of time
If short TTI transmission is supported on a carrier, then transmission delay is reduced, but compatibility with existing LTE system (1ms TTI) cannot be ensured
Solution Approach 1:
The patent makes the carrier universal by enabling it to support multiple TTI lengths (1ms, 2ms, 0.5ms) simultaneously. The base station configures multiple TTI lengths for the terminal, and the terminal can selectively use different TTI lengths based on service requirements. This multi-functionality ensures that the carrier remains compatible with existing LTE systems using 1ms TTI while also supporting short TTI transmissions for delay-sensitive applications.
Data Source
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AI summary
Provided are a method and terminal for data transmission. According to the method, a terminal determines, according to configuration information sent by a base station, to use at least two different TTIs to transmit different PDSCHs and/or PUSCHs on a target carrier. The terminal detects whether first DCI is present in at least one PDCCH in a target subframe on the target carrier, the first DCI being used to schedule at least one PDSCH transmitted in the target subframe on the target carrier. When the terminal detects that the first DCI is not present, or that the first DCI is present and a TTI of the at least one PDSCH scheduled by the first DCI is smaller than the target subframe, the terminal detects dedicated DCI in a dedicated downlink control channel in a target subframe, a TTI of a PDSCH or PUSCH scheduled by the dedicated DCI being smaller than the target subframe.