NR V2X Resource Sensing With Consolidated HARQ-ACK Feedback
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Solution Overview
Problem
Existing 5G New Radio (NR) systems face challenges in efficiently managing hybrid automatic repeat request acknowledgement (HARQ-ACK) information for sidelink communications, particularly in vehicle-to-everything (V2X) scenarios, where reliable resource sensing and transmission of HARQ-ACK information are crucial for enhanced communication reliability and latency.
Innovation Solution
A method and apparatus for a user equipment (UE) to transmit physical sidelink shared channels (PSSCHs) and receive physical sidelink feedback channels (PSFCHs), generating HARQ-ACK information bits, arranging them in a predetermined order, and transmitting the HARQ-ACK codeword in a physical uplink control channel (PUCCH) to facilitate effective HARQ-ACK reporting.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If resource sensing is performed in NR V2X resource allocation, then communication reliability is improved, but system complexity increases due to multiple sensing parameters and configurations
Solution Approach 1:
The patent segments the resource sensing process into distinct components: sensing window configuration, resource selection procedures, and feedback mechanisms. By dividing the complex sensing process into manageable segments with specific parameters (e.g., sensing window size, resource pool configurations), the system maintains reliability while reducing operational complexity.
Solution Approach 2:
The patent implements preliminary resource sensing and channel assessment before actual data transmission. UEs perform sensing during configured sensing windows, identify suitable resources in advance, and prepare transmission buffers beforehand. This preliminary action ensures reliable resource selection while simplifying the real-time transmission process.
2Measurement precision
If HARQ-ACK information is transmitted for each PSSCH transmission, then feedback accuracy is improved, but transmission overhead increases
Solution Approach 1:
The patent merges multiple HARQ-ACK feedback transmissions into consolidated feedback messages. When multiple PSSCH transmissions are acknowledged, the UE combines their ACK/NACK information into a single HARQ-ACK codebook, reducing the number of separate feedback transmissions while maintaining accurate acknowledgment of each individual transmission.
Solution Approach 2:
The patent uses feedback information from previous transmissions to reduce redundant acknowledgments. If a transmission was already acknowledged, subsequent references to the same transport block can use copied acknowledgment status, reducing the quantity of feedback information needed while preserving accuracy.
3Manufacturing precision
If sensing window size is increased to improve resource selection accuracy, then resource allocation precision is improved, but latency increases
Solution Approach 1:
The patent implements dynamic sensing window configuration where the window size adapts based on traffic conditions, channel state, and QoS requirements. For urgent V2X communications, the sensing window is reduced to minimize latency, while for non-critical traffic, a larger window provides more precise resource allocation. This dynamic adjustment resolves the contradiction between precision and latency.
Solution Approach 2:
The patent changes key sensing parameters (window size, threshold values, measurement filters) based on real-time conditions. When latency becomes critical, the system reduces the sensing window size and adjusts resource selection thresholds to enable faster resource acquisition, thereby maintaining acceptable allocation precision while reducing latency.
Data Source
AI summary
A method for a user equipment (UE) to provide hybrid automatic repeat request acknowledgement (HARQ-ACK) information includes transmitting physical sidelink shared channels (PSSCHs), where each of the PSSCH transmissions provides a transport block (TB); receiving physical sidelink feedback channels (PSFCHs); and generating values for HARQ-ACK information bits from the PSFCH receptions. The PSFCH receptions correspond to the PSSCH transmissions and the values of the HARQ-ACK information bits correspond to the TBs in the PSSCH transmissions. The method further includes generating a HARQ-ACK codeword that includes the values of the HARQ-ACK information bits arranged in a predetermined order and transmitting the HARQ-ACK codeword in a physical uplink control channel (PUCCH).