PSFCH Sequence Initialization for Sidelink HARQ Feedback
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing LTE V2X communication primarily supports broadcast communication and lacks efficient mechanisms for unicast and groupcast communication, particularly in out-of-coverage scenarios, and there is a need for improved HARQ feedback mechanisms in sidelink communication.
Innovation Solution
The method involves determining an initialization sequence parameter c_init for cyclic shift calculation in PSFCH design, enabling sequence-based PSFCH resources for HARQ feedback in unicast and groupcast communications, and supporting resource allocation modes in both LTE and NR V2X systems.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If sequence-based PSFCH resources are introduced for HARQ feedback in unicast and groupcast communications, then reliability and spectrum efficiency are improved, but device complexity increases due to the need to determine initialization sequence parameters and manage multiple resource allocation modes
Solution Approach 1:
The patent applies parameter changes by introducing a configurable initialization sequence parameter c_init that can be selected from multiple values (0, 1, or 2) based on resource allocation mode and coverage scenario. This parameter fundamentally changes the sequence generation approach, enabling different PSFCH resources to be distinguished through sequence initialization rather than requiring complex time-frequency resource differentiation, thereby improving reliability while managing complexity through parameter-based discrimination.
Solution Approach 2:
The sequence-based PSFCH design achieves universality by using the same sequence generation mechanism across multiple communication scenarios (unicast, groupcast, in-coverage, out-of-coverage) with different c_init values. This single unified approach replaces what would otherwise require separate HARQ feedback mechanisms for each scenario, reducing overall system complexity while maintaining scenario-specific functionality through parameter selection.
2Adaptability or versatility
If multiple initialization sequence parameter values (0, 1, 2) are used for different resource allocation modes and coverage scenarios, then adaptability is improved, but measurement precision requirements increase for accurately determining and tracking different c_init values across various communication conditions
Solution Approach 1:
The patent introduces an intermediary mechanism in the form of higher layer signaling (RRC signaling) that mediates between the complex reality of multiple coverage scenarios and the simplified UE implementation. The network side determines the appropriate c_init value based on the actual communication scenario and transmits this information to the UE through standardized signaling procedures. This intermediary layer abstracts away the scenario complexity from the UE, allowing accurate c_init determination without requiring the UE to independently measure and discern different coverage conditions.
Solution Approach 2:
The initialization sequence parameter c_init is determined in advance through network configuration before actual data transmission occurs. The network side pre-determines the appropriate c_init value based on the planned communication scenario (unicast, groupcast, in-coverage, out-of-coverage) and communicates this configuration to the UE via RRC signaling. This preliminary determination eliminates the need for real-time measurement and complex dynamic selection at the UE side, reducing measurement precision requirements while maintaining scenario adaptability.
Data Source
Figure 1~2
Figure 3~4
Figure 5
AI summary
Provided in the present invention are a method performed by user equipment and user equipment. The method comprises: determining sidelink resource pool configuration information; receiving a PSCCH and a corresponding PSSCH transmitted by another user equipment; and determining an initialization sequence parameter cinit of a cyclic shift α1 of a sequence for a physical sidelink feedback channel (PSFCH).