Sidelink Control Information Resource Mapping for HARQ Feedback
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Solution Overview
Problem
In the context of LTE and NR sidelink communications, the lack of support for HARQ feedback mechanisms in broadcast transmissions leads to larger sidelink control information (SCI) sizes for unicast and groupcast, causing performance reduction and complexity in detecting SCIs of different sizes, particularly in two-stage SCI transmissions.
Innovation Solution
A resource mapping pattern is employed to jointly schedule first sidelink control information (SCI), second SCI, and sidelink feedback control information (SFCI) for the physical sidelink shared channel (PSSCH), allowing for efficient transmission and mapping of SFCI, which can be multiplexed or mapped individually, based on configuration parameters and service types.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If two-stage SCI transmission is used to support HARQ feedback mechanisms in broadcast, then reliability of sidelink communication is improved, but device complexity increases due to need to detect and process SCIs of different sizes
Solution Approach 1:
The SCI transmission is divided into two stages: first SCI carries basic scheduling information, and second SCI carries additional information including HARQ feedback. This segmentation allows the system to support complex features while keeping individual SCI payloads manageable in size, reducing detection complexity at the receiver.
Solution Approach 2:
The second SCI acts as an intermediary that bridges the first SCI and the actual data transmission. It carries resource allocation information and HARQ feedback that are too detailed for the first SCI but essential for reliable communication, thereby improving reliability without overwhelming the initial control information.
2Ease of operation
If SCI for broadcast is padded to match the size of SCI for unicast/groupcast, then ease of operation is improved, but loss of information occurs due to performance reduction from unnecessary padding
Solution Approach 1:
The SCI structure is made dynamic with variable payload sizes. Broadcast SCI can be smaller than unicast/groupcast SCI when padding is not required, allowing the system to adapt the control information size to the actual transmission needs, thereby avoiding performance loss from unnecessary padding while maintaining ease of processing through standardized formats.
3Loss of information
If no padding is performed for broadcast SCI, then loss of information is avoided, but device complexity increases due to need to detect SCIs of different sizes
Solution Approach 1:
By segmenting SCI into two stages, the system avoids the need to detect variable-size single-stage SCIs. The first SCI has a standardized format that is easy to detect, while the second SCI carries variable information only when needed, thus maintaining performance without increasing detection complexity.
Solution Approach 2:
The first SCI is transmitted and detected first, providing preliminary information about the transmission. Based on this preliminary detection, the receiver knows whether and how to expect a second SCI, thereby avoiding the complexity of detecting SCIs of different sizes from scratch while preserving broadcast SCI performance.
Data Source
AI summary
An information transmission method and a terminal are provided. The method includes: transmitting first sidelink control information SCI, second SCI, and sidelink feedback control information SFCI according to a resource mapping pattern, where the resource mapping pattern is used to indicate transmission resources of the SFCI and a physical sidelink shared channel PSSCH jointly scheduled by the first SCI and the second SCI.