Sidelink Transmission Time Determination via DCI Reception
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In the context of Vehicle-to-Everything (V2X) systems using LTE D2D technology, determining the transmission time for sidelink data is challenging when the sidelink and downlink systems operate with different transmission modes, particularly in scenarios where downlink control signaling is used to allocate transmission resources.
Innovation Solution
A method and device for determining a transmission time, where a terminal receives Downlink Control Information (DCI) from a base station and calculates the time for transmitting sidelink data based on the reception time of the last symbol carrying the DCI, allowing for precise scheduling and reducing transmission delay by aligning with a specific time unit used by the sidelink system.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of time
If the base station schedules sidelink data transmission through DCI with sTTI transmission mode to reduce transmission delay, then the transmission delay is reduced, but it becomes difficult to determine the transmission time when the SL and DL use different transmission modes
Solution Approach 1:
The patent introduces an intermediary mapping relationship between DL time units and SL time units to bridge the two different transmission modes. The base station determines the transmission time in DL time units based on DCI reception time, then maps this to SL time units using a predefined mapping rule, enabling coordination between DL sTTI and SL frame structures
Solution Approach 2:
The patent changes the time unit parameter from SL-specific time units to DL time units for scheduling purposes. By expressing the transmission time in terms of DL time units (which are coarser and more regular), the system can schedule SL transmissions without being constrained by the finer-grained SL time unit structure, simplifying the scheduling mechanism
2Loss of time
If the terminal determines transmission time based on the last symbol carrying DCI, then the transmission delay is reduced, but the precision of time alignment between different systems becomes challenging
Solution Approach 1:
The patent transitions from precise symbol-level timing to a coarser time unit dimension that is common to both DL and SL. By working in DL time units (subframe or slot level) rather than symbol level, the system achieves sufficient timing precision for scheduling while maintaining compatibility with both transmission modes
Solution Approach 2:
The base station pre-determines the transmission time in DL time units before the actual transmission occurs. This preliminary scheduling decision allows the terminal to prepare for transmission at the appropriate SL time unit without requiring real-time precise timing calculations
Data Source
AI summary
Disclosed are a method and device for determining a transmission time, and a computer storage medium. The method includes that: a terminal receives Downlink Control Information (DCI) from a base station at a first time; and the terminal determines, based on the first time, a second time for transmitting sidelink data.