NR V2X PSFCH Overhead Management for TBS Consistency
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In wireless communication systems, especially in V2X communication, it is challenging for User Equipments (UEs) to efficiently determine the transport block size (TBS) when the number of Resource Elements (REs) for the second SCI mapping varies significantly between transmissions.
Innovation Solution
The method involves a UE determining the TBS based on the number of REs for the second SCI mapping, and efficiently managing the number of REs by considering the overheads such as PSFCH and DMRS, to ensure consistent TBS values across transmissions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If the number of REs for the second SCI mapping is greatly changed between transmissions, then the system can adapt to varying transmission conditions, but it becomes difficult to indicate the same TBS value for the transmissions
Solution Approach 1:
The patent applies parameter changes by dynamically adjusting the number of REs for second SCI mapping based on transmission conditions while maintaining TBS consistency through calculated adjustments. The system changes the mapping parameters (number of REs) according to channel conditions, MCS, and transport block size requirements, allowing adaptability while preserving reliable TBS indication through the relationship: TBS = f(N_RE, MCS, overhead). This enables the system to adapt to varying transmission conditions while maintaining consistent TBS values across retransmissions.
2Productivity
If the UE needs to efficiently determine the number of REs for the second SCI mapping, then the communication efficiency is improved, but the complexity of TBS determination increases
Solution Approach 1:
The patent applies preliminary action by pre-configuring the relationship between the number of REs for second SCI mapping and the TBS determination process. The UE efficiently determines the number of REs by using pre-defined formulas and parameters (such as β_offset SCI, MCS, and resource allocation information) before actual transmission. This preliminary determination of RE count based on configured parameters simplifies the overall TBS determination complexity while maintaining high communication efficiency, as the UE doesn't need to perform complex real-time calculations during transmission.
Data Source
Figure 1
Figure 2
Figure 3(a)~3(d)
AI summary
Provided are a method for performing wireless communication by a first device and an apparatus supporting same. The method may comprise: transmitting, to a second device through a physical sidelink control channel (PSCCH), a first sidelink control information (SCI) including information related to a physical sidelink feedback channel (PSFCH) overhead and a beta offset; and transmitting, to the second device through a physical sidelink shared channel (PSSCH) related to the PSCCH, a second SCI, wherein a symbol length related to the PSSCH is obtained based on the information related to the PSFCH overhead, and wherein a number of resource elements (REs) to which the second SCI is mapped is obtained based on the symbol length related to the PSSCH and the beta offset.