Base Station Frequency Synchronization Without Sync Ethernet

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Solution Overview

Problem

Existing communication systems face challenges in maintaining phase synchronization between base stations without relying on synchronous Ethernet, as many fixed transport networks used in cellular networks are not synchronous Ethernet-based, limiting deployment in certain application scenarios.

Innovation Solution

A frequency synchronization method where a first base station obtains and determines the frequency offset of a second base station, calculates the frequency difference between the two, and performs frequency synchronization based on this offset, allowing synchronization without relying on synchronous Ethernet.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If air interface synchronization technology is used to implement phase synchronization between base stations, then synchronization can be achieved, but the adjustment period cannot be too short or the phase difference will fluctuate rapidly

Engineering Contradiction:
Improvephase synchronization accuracyVSAvoidadjustment period
Core Design Contradiction:
Measurement precisionVSDuration of action of moving object

Solution Approach 1:

The patent introduces a frequency offset compensation mechanism as an intermediary between phase synchronization adjustments. By measuring and compensating for frequency offsets between base stations, the system can maintain phase synchronization accuracy over longer periods without frequent adjustments, thus resolving the contradiction between synchronization accuracy and adjustment frequency.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If synchronous Ethernet is used to maintain frequency synchronization, then frequency synchronization can be maintained, but the system depends on synchronous Ethernet infrastructure which is not available in many fixed transport networks

Engineering Contradiction:
Improvefrequency synchronization maintenanceVSAvoiddeployment flexibility
Core Design Contradiction:
ReliabilityVSAdaptability or versatility

Solution Approach 1:

The patent extracts the frequency synchronization function from the synchronous Ethernet infrastructure and implements it directly between base stations using air interface measurements. This removes the dependency on synchronous Ethernet while maintaining frequency synchronization reliability, enabling deployment in networks without such infrastructure.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

Base stations perform self-measurement of frequency offsets using signals received over the air interface, and autonomously adjust their frequency without external synchronization infrastructure. This self-service capability enables deployment flexibility while maintaining synchronization reliability.

Inventive Principle:
Principle #25Self-service

3Stability of the object's composition

If frequent phase adjustments are made to prevent rapid phase fluctuation, then phase synchronization can be maintained, but this increases system complexity and adjustment overhead

Engineering Contradiction:
Improvephase difference stabilityVSAvoidsynchronization system complexity
Core Design Contradiction:
Stability of the object's compositionVSDevice complexity

Solution Approach 1:

The patent performs preliminary measurement and compensation of frequency offsets before phase differences become problematic. By proactively compensating for frequency drift, the system maintains phase stability without requiring frequent reactive adjustments, thereby reducing system complexity while maintaining stability.

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentEP3461189B1Method, base station and system for frequency synchronization
Publication Date: 2020.08.26 HUAWEI TECH CO LTD
  • EP3461189B1 patent drawingFigure 1A~1B
  • EP3461189B1 patent drawingFigure 2~4
  • EP3461189B1 patent drawingFigure 5A~5B

AI summary

Embodiments of the present invention relate to the communications field, and in particular, to frequency synchronization of base stations. In a frequency synchronization method, a first base station obtains a second frequency offset of a second base station, determines a frequency difference between the first base station and the second base station, determines a first frequency offset of the first base station based on the second frequency offset and the frequency difference, and performs frequency synchronization based on the first frequency offset. According to solutions of the embodiments of the present invention, the first base station can determine, through interaction between the first base station and the second base station, the first frequency offset of the first base station without depending on a synchronous Ethernet, to perform frequency synchronization.