Sidelink PRS Signaling for Low-Latency Unlicensed Band Positioning
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing vehicle-to-everything (V2X) and device-to-device (D2D) communication systems face challenges in efficiently accessing unlicensed bands for sidelink positioning reference signals (PRS) due to lengthy listen before talk (LBT) procedures, leading to latency in ranging and positioning operations.
Innovation Solution
Implementing a first type LBT procedure followed by the transmission of a sidelink PRS sequence in an unlicensed band, which conveys information about the LBT procedure to be performed by the receiving device, allowing for reduced latency and fast ranging or positioning by determining a second type LBT procedure based on the received PRS sequence.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a standard LBT procedure is performed before transmitting sidelink PRS sequence in unlicensed band, then channel access compliance is ensured, but transmission latency increases
Solution Approach 1:
The transmitting device performs the LBT procedure and determines the appropriate second type LBT procedure in advance before transmitting the sidelink PRS sequence. This preliminary determination of channel access parameters allows the receiving device to prepare accordingly, reducing overall latency while ensuring compliance with unlicensed band access requirements
Solution Approach 2:
The sidelink PRS sequence acts as an intermediary carrier that conveys information about the second type LBT procedure from the transmitting device to the receiving device. This enables the receiving device to understand what LBT procedure it should perform, coordinating channel access without requiring additional signaling overhead
2Reliability
If both transmitting and receiving devices perform full LBT procedures independently, then channel access reliability is improved, but ranging and positioning speed deteriorates
Solution Approach 1:
The transmitting device provides feedback to the receiving device about the type of LBT procedure that was performed and should be performed in response. This feedback mechanism allows the receiving device to adjust its LBT procedure accordingly, ensuring reliable channel access coordination while reducing the time both devices spend on independent LBT procedures
Solution Approach 2:
The system changes the LBT procedure parameters dynamically based on the transmitting device's channel access experience. By indicating the second type LBT procedure through the sidelink PRS sequence, the system adapts the channel access parameters to current channel conditions, improving both reliability and speed
Data Source
AI summary
Embodiments of the present disclosure relate to method, device and computer readable media for communications. A first device performs a first type LBT procedure in unlicensed band. In response to a successful performing of the first type LBT procedure, the first device transmits, to a second device, a first sidelink positioning reference signal (PRS) sequence in the unlicensed band for ranging between the first device and the second device, and/or for positioning of the first device. The first sidelink PRS sequence is associated with the first type LBT procedure and/or a second type LBT procedure to be performed by the second device for transmitting a second sidelink PRS sequence in the unlicensed band to the first device for the ranging or the positioning.