NR-U Uplink Channel Access for Coexisting Channel Occupancy Time
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Solution Overview
Problem
In New Radio-based access to unlicensed spectrum (NR-U) systems, there is a challenge in ensuring proper coexistence of Channel Occupancy Times (COT) initiated by network and terminal devices, leading to potential collisions and suboptimal system performance.
Innovation Solution
A wireless communication method and devices that enable terminal devices to determine channel access modes for uplink transmissions, allowing them to either share or initiate COT, thereby avoiding collisions and improving system performance on unlicensed spectra.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If terminal device initiates its own COT on unlicensed spectrum, then terminal device can transmit uplink signals, but may cause collision with network device's COT and degrade system performance
Solution Approach 1:
The terminal device performs preliminary actions by determining the channel access mode before the actual uplink transmission. It checks whether to share the network device's COT or initiate a new COT based on pre-determined conditions, thereby avoiding collisions before they occur and ensuring reliable coexistence while maintaining uplink transmission capability.
2Reliability
If terminal device shares network device's COT, then collision is avoided, but terminal device's transmission timing flexibility is reduced
Solution Approach 1:
The system dynamically determines the channel access mode based on real-time conditions. The terminal device can switch between sharing the network device's COT and initiating its own COT depending on transmission timing requirements and network conditions, thereby maintaining both reliable coexistence and transmission timing flexibility.
3Reliability
If terminal device determines channel access mode based on periodic channel occupancy, then coexistence is improved, but system complexity increases
Solution Approach 1:
The terminal device uses periodic channel occupancy patterns to determine channel access modes. By aligning with the periodic nature of COTs in unlicensed spectrum systems, the terminal can simplify its decision-making process while maintaining reliable coexistence, avoiding the need for complex real-time analysis.
Data Source
AI summary
Embodiments of the present disclosure provide a wireless communication method, a terminal device, and a network device. The method includes: determining, by a terminal device, first periodic channel occupancy, the first periodic channel occupancy including channel occupancy for the terminal device to initiate Channel Occupancy Time (COT), and the first periodic channel occupancy including first channel occupancy; and determining, by the terminal device, a channel access mode corresponding to a first uplink transmission, a start position of the first channel occupancy being same as a start position of a first time domain resource being a resource used by the terminal device for transmitting the first uplink transmission. By determining the channel access mode corresponding to the first uplink transmission, the COT initiated by the network device and the COT initiated by the terminal device can properly coexist on an unlicensed spectrum, such that system performance can be improved.