Sidelink HARQ Feedback Across Multiple PSFCHs for Accurate DTX Detection
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Solution Overview
Problem
In sidelink unlicensed spectrum communication, terminal devices incorrectly determine sidelink discontinuous transmission (SL DTX) due to Hybrid Automatic Repeat Request (HARQ) feedback failures, leading to poor communication quality.
Innovation Solution
A method to determine SL DTX by detecting HARQ feedback statuses across multiple Physical Sidelink Feedback Channels (PSFCHs) in a multi-PSFCH mechanism, distinguishing between actual DTX and LBT failures.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a single PSFCH resource is used for HARQ feedback in sidelink unlicensed spectrum communication, then the device complexity is reduced, but the reliability of communication deteriorates due to incorrect DTX determination caused by LBT failures
Solution Approach 1:
The feedback channel is segmented into multiple PSFCH resources (first PSFCH resource and second PSFCH resource) that can be independently selected. This segmentation allows the system to distribute feedback opportunities across multiple resources, reducing the impact of LBT failures on any single resource while maintaining manageable device complexity through structured resource selection based on PSSCH time domain position
Solution Approach 2:
The system dynamically changes the time domain position parameter of PSFCH resources based on the PSSCH transmission position. By mapping different PSSCH time positions to different PSFCH resources, the system adapts feedback resource selection to transmission conditions, improving DTX determination reliability without significantly increasing device complexity
2Reliability
If multiple PSFCH resources are allocated for HARQ feedback, then the reliability of DTX determination improves, but the device complexity and resource overhead increase
Solution Approach 1:
The system performs preliminary determination of the appropriate PSFCH resource based on the PSSCH time domain position before actual feedback transmission. This preliminary action allows both transmitting and receiving devices to pre-coordinate which resource will be used, avoiding complex real-time negotiations and reducing device complexity while maintaining high reliability through consistent resource selection
Solution Approach 2:
The system uses the existing PSSCH time domain position information to automatically determine the corresponding PSFCH resource without requiring additional signaling or complex coordination. This self-service mechanism leverages already-available transmission parameters to select feedback resources, reducing overhead and device complexity while ensuring reliable DTX determination
Data Source
AI summary
Embodiments of this application provide a communication method and a communication apparatus. One example communication method includes: A first terminal device sends first information to a second terminal device, where the first information is carried on a PSSCH, and the PSSCH corresponds to at least two candidate physical sidelink feedback channel (PSFCH) resources; and the first terminal device determines, based on second information and/or third information, that discontinuous transmission (DTX) occurs, where the second information indicates that the first terminal device does not receive HARQ feedback information at positions of the at least two candidate PSFCH resources.