Uplink Signal Timing Compensation for Satellite Time Drift

Solution Overview

Problem

In satellite communication, the high-speed movement of satellites causes significant time synchronization drift during long-time signal transmission, leading to reduced coding performance at satellite base stations due to unsynchronized signal periods.

Innovation Solution

A method and apparatus that insert time intervals between uplink signal periods based on timing advance change rates to compensate for time synchronization drift, improving coding performance by aligning signal periods with satellite movement.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Area of stationary object

If the terminal sends repeated uplink signals for long-time transmission to improve deep coverage, then the coverage area is enhanced, but time synchronization drift increases due to satellite high-speed movement

Engineering Contradiction:

Improvecoverage areaVSAvoidtime synchronization

Core Design Contradiction:

Area of stationary objectVSMeasurement precision

Solution Approach 1:

The patent applies preliminary action by calculating the time synchronization drift in advance based on satellite movement parameters (orbital velocity, position, and time) and compensating for it before signal transmission. The terminal device computes the drift value using satellite ephemeris data and adjusts its uplink signal timing accordingly, preventing synchronization errors rather than correcting them after they occur.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent implements parameter changes by dynamically adjusting the timing parameters of uplink signals based on real-time satellite position and velocity information. The terminal modifies transmission time offsets according to calculated drift values, which change as satellite orbital parameters evolve during the communication session, thereby maintaining synchronization despite satellite movement.

Inventive Principle:

Principle #35Parameter changes

2Reliability

If the terminal sends repeated uplink signals for long-time transmission, then deep coverage is improved, but coding performance deteriorates due to time synchronization drift

Engineering Contradiction:

Improvedeep coverageVSAvoidcoding performance

Core Design Contradiction:

ReliabilityVSManufacturing precision

Solution Approach 1:

The patent applies preliminary action by calculating the time synchronization drift in advance based on satellite movement parameters (orbital velocity, position, and time) and compensating for it before signal transmission. The terminal device computes the drift value using satellite ephemeris data and adjusts its uplink signal timing accordingly, preventing synchronization errors rather than correcting them after they occur.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent implements parameter changes by dynamically adjusting the timing parameters of uplink signals based on real-time satellite position and velocity information. The terminal modifies transmission time offsets according to calculated drift values, which change as satellite orbital parameters evolve during the communication session, thereby maintaining synchronization despite satellite movement.

Inventive Principle:

Principle #35Parameter changes

3Stability of the object's composition

If the terminal and base station are stationary or move slowly in terrestrial network, then long-time signal transmission does not cause large time synchronization drift, but satellite high-speed movement causes significant drift

Engineering Contradiction:

Improvetime synchronization stabilityVSAvoidsatellite movement speed

Core Design Contradiction:

Stability of the object's compositionVSSpeed

Solution Approach 1:

The patent implements parameter changes by dynamically adjusting the timing parameters of uplink signals based on real-time satellite position and velocity information. The terminal modifies transmission time offsets according to calculated drift values, which change as satellite orbital parameters evolve during the communication session, thereby maintaining synchronization despite satellite movement.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent applies feedback by continuously monitoring satellite position and velocity data, calculating the resulting time synchronization drift, and using this information to adjust uplink signal timing. The terminal receives satellite ephemeris information, computes drift values, and applies corrections in a closed-loop manner to maintain synchronization stability despite high-speed satellite movement.

Inventive Principle:

Principle #23Feedback

Data Source

PatentUS12439354B2Uplink signal sending and receiving method, and apparatus

Publication Date: 2025.10.07 HUAWEI TECH CO LTD

AI summary

An uplink signal sending and receiving method includes that a first communication apparatus obtains a first timing advance (TA) change rate, and sends an uplink signal in a plurality of first time periods. There is a first time interval between the plurality of first time periods to compensate for a time synchronization drift. A length of the first time interval and a location of the first time interval between the plurality of first time periods are determined based on the first TA change rate, and the first TA change rate is a TA change rate in a communication process of the first communication apparatus.