Coherent Optical Reception with Subcarrier Dispersion Compensation
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Solution Overview
Problem
Existing equalization processing for longer-distance optical transmission requires a large circuit scale and high power consumption for dispersion compensation.
Innovation Solution
An optical reception apparatus that performs wavelength dispersion compensation and delay compensation individually on subcarrier-by-subcarrier basis using a coherent detecting scheme, with a subcarrier division unit, wavelength dispersion compensation units, and delay compensation units to reduce power consumption.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Length of moving object
If equalization processing is performed for longer-distance optical transmission, then transmission distance is improved, but power consumption and circuit scale increase
Solution Approach 1:
The patent divides the optical signal into multiple subcarriers (first subcarrier, second subcarrier, etc.) and performs wavelength dispersion compensation individually on each subcarrier. This segmentation allows the system to achieve long-distance transmission by processing each subcarrier separately with smaller, more energy-efficient compensation circuits, rather than using a single large-scale equalization processor.
2Length of moving object
If equalization processing is performed for longer-distance optical transmission, then transmission distance is improved, but circuit scale increases
Solution Approach 1:
The patent divides the optical signal into multiple subcarriers and performs wavelength dispersion compensation individually on each subcarrier using separate compensation circuits. This segmentation enables the use of multiple small-scale circuits instead of one large-scale equalization processor, thereby achieving long-distance transmission while keeping individual circuit scales manageable.
Solution Approach 2:
The patent introduces a frequency dimension by dividing the signal into multiple subcarriers at different frequencies. This dimensional transformation allows the system to handle dispersion compensation in the frequency domain separately for each subcarrier, reducing the complexity of time-domain equalization circuits while maintaining long-distance transmission capability.
3Use of energy by moving object
If subcarrier division and individual compensation is performed, then power consumption is reduced, but processing complexity increases
Solution Approach 1:
The patent segments the optical signal into multiple subcarriers and assigns a dedicated wavelength dispersion compensation circuit to each subcarrier. While this creates multiple processing paths, each path is simple and energy-efficient, and the overall system benefits from parallel processing that reduces total power consumption despite the increased number of components.
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 dispersion compensation with reduced power consumption by dividing and compensating for wavelength dispersion and delays among subcarriers, thereby minimizing the circuit scale needed for dispersion compensation.
Implementation Method 1
a coherent detecting unit that receives the optical signal and performs coherent detection
Data Source
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AI summary
An optical reception apparatus includes a wavelength dispersion compensation unit that performs wavelength dispersion compensation individually on reception signals that are obtained by receiving, by a coherent detecting scheme, an optical signal modulated in a subcarrier modulation scheme and by performing division on a subcarrier-by-subcarrier basis, and a plurality of delay compensation units that compensate for a delay between reception signals at different subcarriers among the reception signals at subcarriers obtained by the wavelength dispersion compensation.