Uplink Timing Adjustment in Satellite Communication

Solution Overview

Problem

The existing methods for addressing uplink timing drift in satellite communication, particularly in 5G systems, face challenges such as large deviations in timing adjustments and high signaling overheads due to the need for frequent calculations and data transmission.

Innovation Solution

A satellite communication method where the terminal device receives information about a timing change rate range from the satellite, measures the downlink timing change rate, and determines the uplink timing change rate based on this information to adjust the uplink timing, reducing the need for satellite-calculated and transmitted uplink timing rates and improving precision.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If the satellite calculates and sends UE-specific timing change rate, then the uplink timing adjustment precision is improved, but the calculation time period and signaling overheads increase

Engineering Contradiction:

Improveuplink timing adjustment precisionVSAvoidcalculation time period

Core Design Contradiction:

Measurement precisionVSLoss of time

Solution Approach 1:

The terminal device autonomously measures the downlink timing change rate and determines its own uplink timing change rate based on the indicated range, eliminating the need for the satellite to calculate and send UE-specific timing change rates, thereby reducing calculation time and signaling overhead while maintaining adjustment precision

Inventive Principle:

Principle #25Self-service

Solution Approach 2:

The timing change rate is divided into a common timing change rate (sent by satellite) and a terminal-specific measurement component (measured by terminal), allowing the satellite to provide general guidance while terminals adjust based on their specific conditions

Inventive Principle:

Principle #1Segmentation

2Measurement precision

If the satellite calculates and sends UE-specific timing change rate, then the uplink timing adjustment precision is improved, but the signaling overheads increase

Engineering Contradiction:

Improveuplink timing adjustment precisionVSAvoidsignaling overheads

Core Design Contradiction:

Measurement precisionVSLoss of information

Solution Approach 1:

The terminal device autonomously measures the downlink timing change rate and determines its own uplink timing change rate based on the indicated range, eliminating the need for the satellite to calculate and send UE-specific timing change rates, thereby reducing calculation time and signaling overhead while maintaining adjustment precision

Inventive Principle:

Principle #25Self-service

Solution Approach 2:

Instead of the satellite determining the timing change rate for the terminal, the terminal independently measures and determines its own timing change rate within the range indicated by the satellite, inverting the traditional control direction to reduce signaling overhead

Inventive Principle:

Principle #13The other way round (Inversion)

3Loss of information

If the satellite sends common timing advance change rate, then the signaling overheads are reduced, but the uplink timing adjustment precision deteriorates due to large deviation

Engineering Contradiction:

Improvesignaling overheadsVSAvoiduplink timing adjustment precision

Core Design Contradiction:

Loss of informationVSMeasurement precision

Solution Approach 1:

The timing change rate is divided into a common timing change rate (sent by satellite) and a terminal-specific measurement component (measured by terminal), allowing the satellite to provide general guidance while terminals adjust based on their specific conditions, thus maintaining low signaling overhead while improving precision

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The terminal device measures the downlink timing change rate and uses this feedback to autonomously determine the uplink timing change rate, creating a closed-loop system that improves precision without increasing satellite signaling overhead

Inventive Principle:

Principle #23Feedback

Data Source

PatentUS12120566B2Satellite communication method and apparatus

Publication Date: 2024.10.15 HUAWEI TECH CO LTD

AI summary

This application provides example satellite communication methods and example apparatuses. One example method includes receiving, by a terminal device, first information sent by a satellite, where the first information indicates a first timing change rate range. The terminal device can then measure a downlink timing change rate to obtain a first downlink timing change rate. The terminal device can then determine a first uplink timing change rate based on the first downlink timing change rate and the first timing change rate range. The terminal device can then perform uplink communication with the satellite based on the first uplink timing change rate.