Random Access Timing Advance for NTN Delay Compensation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In non-terrestrial networks, the large communication delay caused by satellites moving at high speeds leads to significant timing advance issues, resulting in inaccurate timing advances and prolonged random access procedures due to uncertainty in determining the delay compensation.
Innovation Solution
The terminal autonomously or non-autonomously determines timing advance, adjusting feedback information reception based on different receiving timing information to compensate for delays, using either accurate self-determined or network-provided timing advances.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of stationary object
If satellites are used for coverage in non-terrestrial networks, then ground coverage is improved, but communication delay increases significantly
Solution Approach 1:
The terminal performs preliminary timing advance determination before the random access procedure. The terminal calculates the timing advance value based on its known location and the satellite's orbital parameters, allowing it to pre-compensate for the large propagation delay inherent in satellite communication. This preliminary action enables the terminal to send uplink signals with appropriate timing adjustment before actual communication begins, resolving the contradiction between achieving ground coverage and managing communication delay.
2Measurement precision
If timing advance is determined autonomously by the terminal, then synchronization accuracy is improved, but timing advance error increases due to large delay
Solution Approach 1:
The base station provides feedback information to the terminal during the random access procedure, including timing adjustment commands and synchronization information. The terminal uses this feedback to refine its autonomously determined timing advance value, correcting errors that arose from autonomous calculation. This feedback mechanism allows the system to maintain both the benefits of autonomous determination (synchronization accuracy) while compensating for its drawbacks (timing advance error due to large delay).
Solution Approach 2:
The system performs preliminary timing advance determination at the terminal side using location information and orbital parameters before the random access procedure begins. This preliminary calculation provides an initial timing advance value that is then refined through feedback from the base station, allowing the system to address timing synchronization issues proactively rather than reactively.
3Device complexity
If a single receiving timing information is used for feedback, then device complexity is reduced, but synchronization accuracy deteriorates due to different timing advance determination methods
Solution Approach 1:
The system configures different receiving timing information parameters specifically for terminals that autonomously determine timing advance versus those that do not. Terminals that perform autonomous timing advance determination receive specific timing configuration parameters that account for their pre-calculated timing values, while other terminals use standard timing configurations. This localized quality approach ensures that each terminal type receives appropriately optimized timing information, maintaining synchronization accuracy without unnecessarily increasing overall system complexity.
Data Source
AI summary
A method for random access is applied to a terminal, and includes: receiving feedback information from a base station during a random access procedure according to at least one of first receiving timing information or second receiving timing information; wherein the first receiving timing information and the second receiving timing information correspond to different manners for determining a timing advance by the terminal; and wherein the first receiving timing information is different from the second receiving timing information.