Optical Transmitter Delay Skew Monitoring via Correlation
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Solution Overview
Problem
Existing optical communication systems face challenges in real-time monitoring of delay skew between sub-signals without disrupting normal communication, particularly due to environmental changes, which affect system performance.
Innovation Solution
A method and apparatus using correlation of high-speed sub-signals and another high-speed signal to monitor delay skew in optical transmitters, employing electro-optical conversion units and low-bandwidth electrical devices for real-time skew adjustment without requiring expensive signal analysis equipment.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If real-time monitoring of delay skew is implemented using traditional signal analysis equipment, then measurement precision is improved, but device complexity and cost increase significantly
Solution Approach 1:
The patent creates a virtual copy of the high-speed signal path by generating test signals that traverse the same electro-optical conversion units as the actual data signals. By measuring the delay of these copied test signals, the system obtains delay skew information without requiring direct high-speed sampling of the main communication signals, thus reducing equipment complexity while maintaining measurement precision.
Solution Approach 2:
The patent introduces an intermediary test signal mechanism that mediates between the high-speed communication signals and the measurement system. Instead of directly analyzing the complex high-speed signals, the system uses specially designed test signals with known characteristics that pass through the same hardware path, allowing delay measurement through correlation analysis at lower speeds while the actual communication remains unaffected.
2Reliability
If real-time monitoring is performed continuously, then reliability is improved, but loss of energy increases
Solution Approach 1:
The patent implements periodic monitoring by inserting test signals at specific intervals rather than continuously. The monitoring is triggered by dedicated test frames or synchronization signals that occur periodically in the communication stream, allowing the system to maintain reliability through regular checks while consuming energy only during these periodic measurement intervals, thus reducing overall energy loss.
3Measurement precision
If calibration is performed frequently to maintain precision, then measurement precision is improved, but loss of time increases
Solution Approach 1:
The patent implements continuous feedback-based calibration where the delay skew measurements are constantly monitored and compared against threshold values. Instead of performing full calibration sequences frequently, the system only triggers recalibration when the feedback indicates that delay skew has exceeded acceptable limits, thus maintaining precision while minimizing the time lost to calibration operations.
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
Enables real-time monitoring of delay skew without disrupting communication, using low-bandwidth electrical devices and flexible implementation across various optical transmitters, reducing the need for high-speed equipment.
Implementation Method 1
input a first input signal to a first electro-optical conversion unit, to enable the first electro-optical conversion unit to modulate to-be-modulated light according to the first input signal and to obtain a first output signal
Data Source
AI summary
An apparatus and a method for real-time monitoring delay skew of a sub-signal of an optical transmitter may include inputting a first input signal to a first electro-optical conversion unit, modulating to-be-modulated light to obtain a first output signal; inputting a second input signal to a second electro-optical conversion unit, modulating to-be-modulated light to obtain a second output signal, the second input signal is a differential signal of the first input signal; performing correlation operation processing on the first output signal and the second output signal to obtain correlation of the first input signal and the second input signal; and determining delay skew between an output signal of the first electro-optical conversion unit and an output signal of the second electro-optical conversion unit according to the correlation and a pre-set corresponding relation between a correlation and the delay skew. Hence, delay skew between two high-speed signals may be monitored by only using a low-bandwidth electrical device without using a high-speed equipment.