PSFCH Capability Signaling for V2X Groupcast HARQ Feedback
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Solution Overview
Problem
The existing 3GPP standard does not define a maximum number of physical sidelink feedback channels (PSFCHs) that a terminal can receive or transmit, leading to potential overload and increased workload in determining HARQ ACK/NACK for multiple receiving terminals in groupcast mode.
Innovation Solution
A terminal signals its maximum PSFCH receiving and transmission capabilities to the base station, and measures and sorts PSFCHs based on RSRP or SINR to efficiently determine HARQ ACK/NACK, thereby managing PSFCH operations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If the number of receiving terminals in groupcast mode increases, then the coverage and communication capability are improved, but the number of PSFCHs to be received increases beyond terminal capability
Solution Approach 1:
The patent extracts only the necessary PSFCHs for processing by selecting a subset of PSFCHs based on RSRP/SINR thresholds. Instead of processing all PSFCHs from multiple receiving terminals, the terminal identifies and processes only those PSFCHs that meet the quality criteria, thereby reducing the effective number of PSFCHs that need to be handled while maintaining groupcast functionality.
Solution Approach 2:
The patent applies local quality by differentiating between PSFCHs based on their signal quality (RSRP/SINR). High-quality PSFCHs above the threshold are processed for HARQ-ACK determination, while low-quality PSFCHs below the threshold are discarded. This selective processing based on local signal quality enables the terminal to handle groupcast scenarios without being overwhelmed by the total number of PSFCHs.
2Reliability
If all PSFCHs from multiple receiving terminals are processed to determine HARQ ACK/NACK, then communication reliability is improved, but the workload and processing time increase
Solution Approach 1:
The patent extracts only the critical PSFCHs that contribute meaningfully to HARQ feedback accuracy. By removing low-quality PSFCHs (those below RSRP/SINR thresholds) from the processing set, the terminal reduces computational workload while retaining the reliability needed for accurate HARQ-ACK determination from the remaining high-quality feedback signals.
Solution Approach 2:
The patent applies partial action by processing only a subset of PSFCHs rather than all received PSFCHs. This selective processing approach performs sufficient action (processing enough quality PSFCHs to ensure reliable HARQ feedback) without excessive action (processing every single PSFCH which would waste resources), thereby optimizing the balance between reliability and workload.
3Productivity
If the terminal receives and processes a large number of PSFCHs, then groupcast communication capacity is improved, but the terminal's PSFCH receiving capability is exceeded
Solution Approach 1:
The patent extracts and processes only the essential PSFCHs that meet quality criteria, effectively reducing the burden on terminal processing capacity. By filtering out low-quality PSFCHs, the terminal can maintain groupcast communication capacity through selective processing of manageable numbers of high-value PSFCHs, preventing overload while preserving productivity.
Solution Approach 2:
The patent changes the processing parameters by introducing RSRP and SINR thresholds as filtering criteria. This parameter-based selection transforms the raw quantity of PSFCHs into a quality-filtered subset, allowing the terminal to operate within its processing capabilities while maintaining effective groupcast communication throughput through intelligent parameter-driven selection.
Data Source
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AI summary
An operating method of a terminal configured to perform vehicle-to-everything (V2X) communication in a wireless communication system, the operating method comprising: signaling a physical sidelink feedback channel (PSFCH) capability to a base station, wherein the PSFCH capability is a maximum number of PSFCHs which are processable during a time transmission interval (TTI).