Base Station Microwave Link Clock Synchronization

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Solution Overview

Problem

The installation of base station apparatuses requires costly optical cables for data transmission between radio equipment control and radio equipment, leading to increased costs.

Innovation Solution

Implementing a wireless communication system using microwave apparatuses to transmit and receive baseband signals, with the ability to switch between regular and dummy clock signals based on frequency fluctuation, ensuring synchronization accuracy and maintaining communication links.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If optical cables are installed for data transmission between radio equipment control and radio equipment, then data transmission reliability is improved, but installation cost increases

Engineering Contradiction:

Improvedata transmission reliabilityVSAvoidinstallation cost

Core Design Contradiction:

ReliabilityVSEase of manufacture

Solution Approach 1:

The patent replaces the mechanical cable connection system with a wireless microwave transmission system. The microwave apparatus transmits baseband signals between radio equipment control and radio equipment through radio waves, eliminating the need for optical cables and reducing installation costs while maintaining data transmission functionality

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent changes the transmission medium parameter from physical cable (optical fiber) to electromagnetic wave (radio wave). By converting the data transmission method from wired to wireless, the system achieves cost reduction while maintaining reliability through proper signal modulation and synchronization mechanisms

Inventive Principle:

Principle #35Parameter changes

2Ease of manufacture

If wireless transmission is used instead of optical cables, then installation cost is reduced, but synchronization accuracy may deteriorate due to frequency fluctuations

Engineering Contradiction:

Improveinstallation costVSAvoidsynchronization accuracy

Core Design Contradiction:

Ease of manufactureVSMeasurement precision

Solution Approach 1:

The patent implements a feedback mechanism where the microwave apparatus monitors the frequency of the extracted clock signal and compares it against the expected frequency. When frequency fluctuations are detected, the system generates dummy data to maintain synchronization, creating a closed-loop control system that corrects synchronization errors

Inventive Principle:

Principle #23Feedback

Solution Approach 2:

The patent prepares dummy data in advance as a cushioning measure. When frequency fluctuations occur, the microwave apparatus can immediately switch to generating dummy data instead of using the fluctuating clock signal, preventing synchronization errors from affecting data transmission quality

Inventive Principle:

Principle #11Beforehand cushioning (Prior cushioning)

3Measurement precision

If clock frequency extraction is performed from received signals, then synchronization is improved, but system complexity increases due to frequency monitoring and dummy data generation

Engineering Contradiction:

Improvesynchronization accuracyVSAvoidsystem complexity

Core Design Contradiction:

Measurement precisionVSDevice complexity

Solution Approach 1:

The microwave apparatus performs self-service by automatically extracting the clock signal from the received baseband signal and monitoring its own frequency output. The system self-adjusts by switching between real data and dummy data generation based on its own frequency measurements, eliminating the need for external synchronization control

Inventive Principle:

Principle #25Self-service

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

This approach reduces the need for optical cables, lowers installation costs, and maintains synchronization accuracy and communication standards even during frequency fluctuations.

Implementation Method 1

a first microwave apparatus that modulates the first baseband signal to a first microwave to transmit by radio

Methodology Applied

Scientific EffectModulation: Phase Modulation

Implementation Method 2

a second microwave apparatus that demodulates the received first microwave to the first baseband signal

Methodology Applied

Scientific EffectDemodulation: Homodyne Detection

Implementation Method 3

then extracts a first clock from a cycle of the first data included in the first baseband signal

Methodology Applied

Scientific EffectClock extraction:

Implementation Method 4

imports the first baseband signal in synchronization with the first clock

Methodology Applied

Scientific EffectSynchronization: Feedback

Data Source

PatentUS10250378B2Base station apparatus and method for controlling base station apparatus

Publication Date: 2019.04.02 NEC CORP

AI summary

According to one embodiment, a base station apparatus includes: a radio equipment control that generates a baseband signal including data; a microwave apparatus that modulates the baseband signal to a microwave to transmit by radio; a microwave apparatus that demodulates the received first microwave to the baseband signal, then extracts a clock from a cycle of the data included in the baseband signal, imports the baseband signal in synchronization with the clock, and plays back the data; and a radio equipment that modulates the data played back by the microwave apparatus to a high-frequency signal, and the microwave apparatus outputs dummy data instead of the played back data when a frequency fluctuation amount of the clock exceeds a predetermined range.