TDD Uplink Timing Advance Control for Propagation Delay Interference
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Solution Overview
Problem
In wireless communication systems, particularly for flying bodies like drones, long propagation delays in time-division duplex (TDD) can cause interference with other communication terminals due to mismatched timing and guard periods, leading to communication failures.
Innovation Solution
A control device with a detection unit that identifies propagation delays exceeding a threshold and a suppression unit that adjusts resource allocation and timing in the TDD system to prevent interference by synchronizing guard periods and adjusting the timing of uplink communications.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of stationary object
If a wireless communication terminal is connected to a distant base station, then coverage area is improved, but propagation delay increases causing interference with other terminals
Solution Approach 1:
The patent applies local quality by configuring terminal-specific timing advance values based on each terminal's distance from the base station. Remote terminals receive larger timing advance values to compensate for their propagation delay, while nearby terminals receive smaller values. This localized adjustment ensures each terminal transmits at the correct time relative to the base station, preventing interference with other terminals while maintaining wide coverage.
Solution Approach 2:
The patent implements preliminary action by having the base station pre-calculate and notify each terminal of its specific timing advance value before uplink transmission begins. The terminal uses this pre-configured value to adjust its transmission timing in advance, ensuring that even with long propagation delays, the uplink signal arrives at the base station synchronized with the expected time window and does not interfere with downlink transmissions from other cells.
2Reliability
If guard period is extended to accommodate propagation delay, then interference is reduced, but uplink transmission time is reduced
Solution Approach 1:
Instead of uniformly extending the guard period for all terminals, the patent applies local quality by assigning individual timing advance values to each terminal based on its distance. This allows the system to maintain the original guard period length while achieving interference suppression through precise timing adjustment of each terminal's transmission, thereby preserving uplink transmission capacity.
3Reliability
If timing is adjusted for remote terminal, then propagation delay is compensated, but interference with nearby terminals occurs
Solution Approach 1:
The patent resolves this contradiction by applying local quality through terminal-specific timing advance configuration. Each terminal receives a customized timing advance value calculated based on its individual distance from the base station. Remote terminals are advanced more, while nearby terminals are advanced less or not at all. This localized adjustment ensures that all terminals, regardless of distance, arrive at the base station synchronized with the expected time window, preventing both propagation delay issues and interference with other terminals.
Data Source
AI summary
If a propagation delay equal to or greater than a threshold value is detected in the uplink of a time-division duplex between a first wireless communication terminal and a first wireless base station, a suppression unit 52 performs control pertaining to resources in the time-division duplex of a first wireless communication terminal. Thereby, communication errors that occur in a second wireless communication terminal wirelessly connected to the second wireless base station that is different from the first wireless base station, to which the first wireless communication terminal is wirelessly connected, is suppressed by uplink communication performed by the first wireless communication terminal in accordance with the propagation delay. For example, this suppression process is a process pertaining to the assignment of resources a time-division duplex with respect to the first wireless communication terminal.