Uplink Bandwidth Switching Timing for Large-Delay Wireless Links
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In wireless communication systems with large round-trip delays, such as non-terrestrial networks (NTN), the base station struggles to receive uplink information accurately due to timing misalignment caused by significant timing advance values, leading to missed signals when bandwidth switching occurs.
Innovation Solution
A method and apparatus that determine a switching delay based on a timing offset value derived from the round-trip delay, allowing the terminal device to switch transmission bandwidths at an appropriate time to ensure the base station can receive uplink information accurately.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the base station switches bandwidth before receiving SR information due to large TA value, then the base station can prepare for upcoming communication, but the base station cannot receive SR information sent by the terminal device
Solution Approach 1:
The base station performs bandwidth switching in advance based on predicted timing, but the patent resolves the contradiction by introducing a mechanism where the terminal device sends indication information to notify the base station of the actual bandwidth switching timing, ensuring the base station switches bandwidth at the correct moment to receive SR information
Solution Approach 2:
The terminal device provides feedback to the base station through indication information, informing the base station when bandwidth switching will occur. This feedback mechanism allows the base station to adjust its bandwidth switching timing accordingly, ensuring it can receive SR information accurately
2Measurement precision
If the terminal device sends SR information 4 ms to 541 ms in advance due to large round-trip delay, then timing alignment is achieved, but the base station has already switched bandwidth and cannot receive the SR information
Solution Approach 1:
The terminal device sends indication information to the base station to feedback the actual bandwidth switching timing. This feedback allows the base station to adjust its bandwidth switching timing to match the terminal device's transmission timing, resolving the mismatch caused by large TA values
Solution Approach 2:
The bandwidth switching timing is made dynamic rather than fixed. The base station adjusts its bandwidth switching timing based on the indication information received from the terminal device, allowing the system to adapt to the large round-trip delay characteristics of NTN scenarios
Data Source
Figure 1
Figure 2A
Figure 2B
AI summary
A wireless communication method and an apparatus are provided. The method includes: A first communication apparatus obtains first indication information in a first slot, where the first indication information indicates the first communication apparatus to switch from an uplink transmission bandwidth to a first transmission bandwidth; then, the first communication apparatus determines a second slot based on the first slot and a first switching delay, where the first switching delay is determined based on a first timing offset value, and the first timing offset value is determined based on a round-trip delay between a first location in an area covered by a second communication apparatus and the second communication apparatus; and the first communication apparatus sends uplink information to the second communication apparatus by using the first transmission bandwidth from the second slot. Therefore, in an uplink transmission bandwidth switching process, this method can ensure that the second communication apparatus can receive the uplink information sent by the first communication apparatus.