Sidelink PSFCH Resource Mapping for Unlicensed Channel Conflicts
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Solution Overview
Problem
Existing communication systems face challenges in transmitting feedback channels on sidelinks in unlicensed frequency bands due to the need to identify and respect channel occupancy states, which can lead to resource conflicts.
Innovation Solution
A method for determining and transmitting physical sidelink feedback channels (PSFCH) by identifying suitable PRB sets and slots based on slot indices, terminal IDs, and cyclic shifts, considering transmission modes and HARQ feedback states, and using Zadoff-Chu sequences for unlicensed frequency usage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a terminal transmits feedback channel on sidelink in unlicensed band, then communication efficiency is improved, but channel occupancy conflicts increase
Solution Approach 1:
The feedback channel resources are segmented into multiple PRB sets, where each PRB set corresponds to different feedback information types. This segmentation allows different terminals to be assigned to different PRB sets, reducing channel occupancy conflicts while maintaining communication efficiency in unlicensed bands.
Solution Approach 2:
The system performs preliminary identification of channel occupancy state before allocating feedback channel resources. By checking channel availability in advance and pre-assigning PRB sets based on channel conditions, the system prevents conflicts before they occur, enabling efficient feedback transmission in unlicensed bands.
2Manufacturing precision
If PRB sets are identified based on slot index and subchannel index, then resource allocation precision is improved, but system complexity increases
Solution Approach 1:
The system uses parameter changes (slot index, subchannel index, PRB index) to dynamically identify and allocate feedback channel resources. By changing these parameters based on channel conditions and traffic requirements, the system achieves precise resource allocation while managing complexity through standardized parameter relationships.
Solution Approach 2:
The PRB set identification mechanism serves multiple functions: it allocates feedback resources, tracks channel occupancy, and manages terminal assignments. This multi-functionality reduces the need for separate mechanisms, thereby controlling system complexity while maintaining allocation precision.
3Adaptability or versatility
If feedback channel transmission follows unlicensed frequency conditions, then spectrum utilization is improved, but transmission reliability decreases
Solution Approach 1:
The system implements feedback mechanisms where terminals report channel occupancy states and feedback reception status. This feedback loop allows the system to adapt to unlicensed band conditions, identify conflicts, and reassign resources, thereby maintaining transmission reliability while utilizing unlicensed spectrum efficiently.
Solution Approach 2:
The system prepares multiple candidate PRB sets and has pre-established fallback allocation schemes. When channel conditions change or conflicts arise in unlicensed bands, the system can switch to alternative PRB sets without interrupting feedback transmission, cushioning against reliability degradation while maintaining spectrum utilization.
Data Source
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AI summary
The present invention relates to technology for feedback in an inter-terminal communication of a communication system. A method performed by a first terminal may comprise the steps of: receiving a PSSCH in a slot n from a second terminal through a sub-channel; determining PRB sets for transmitting a PSFCH corresponding to the PSSCH on the basis of the slot n and an index of the sub-channel; identifying a PRB set for transmitting the PSFCH among the PRB sets; identifying a slot, configured in order to transmit the PSFCH, K slots after the slot n; and using the identified PRB to transmit the PSFCH in the identified slot, wherein n and K are positive integers.