Wavelength Dispersion Compensation With Adaptive Window Optimization
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Solution Overview
Problem
Conventional signal processing methods for chromatic dispersion compensation in digital coherent optical communication suffer from deteriorated compensation accuracy and signal quality due to suboptimal weighting coefficients in frequency domain signal combination.
Innovation Solution
A chromatic dispersion compensation device and method that optimizes the weighting coefficient by dividing input signals into blocks with overlaps, performing Fourier transforms, multiplying by dispersion compensation coefficients and window functions, and minimizing waveform distortion through inverse Fourier transforms and overlap removal, using methods like least squares to optimize the window function.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional signal processing method is used with fixed block division and standard window function, then processing complexity is reduced, but chromatic dispersion compensation accuracy deteriorates
Solution Approach 1:
The patent applies dynamics by making the window function adaptive rather than fixed. The optimization unit dynamically adjusts the window function coefficients based on the actual signal characteristics and chromatic dispersion conditions, allowing the system to adapt to varying transmission scenarios and maintain high compensation accuracy without excessive complexity
Solution Approach 2:
The patent implements feedback through the optimization unit that evaluates compensation results and adjusts the window function accordingly. This feedback mechanism allows the system to learn from actual performance and continuously improve compensation accuracy, resolving the contradiction between simplicity and precision
2Speed
If block division with overlap is used for parallel processing, then processing speed is improved, but waveform distortion increases due to suboptimal weighting
Solution Approach 1:
The patent applies local quality by optimizing the window function to have different coefficients for different blocks and overlap regions. This allows each local region to be processed with optimal weighting, maintaining waveform accuracy while enabling parallel processing speed benefits
Solution Approach 2:
The patent changes the parameters of the window function through optimization, adjusting coefficients based on block position, overlap amount, and chromatic dispersion characteristics. This parameter optimization resolves the contradiction by finding the optimal balance between processing efficiency and waveform fidelity
3Stability of the object's composition
If overlap amount between blocks is increased to improve continuity, then signal continuity is improved, but processing load increases
Solution Approach 1:
The patent applies partial action by optimizing the overlap amount to be sufficient for continuity but not excessive. The optimization unit determines the minimal necessary overlap and corresponding window function coefficients, achieving signal continuity while avoiding unnecessary processing load
Solution Approach 2:
The patent optimizes the overlap parameter along with window function coefficients, finding the optimal balance point where signal continuity is achieved without excessive processing requirements
Data Source
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AI summary
A chromatic dispersion compensation device including: a block division unit that divides an input signal on which chromatic dispersion distortion is loaded into blocks of a fixed length such that an overlap of a predetermined length with an adjacent block is generated; a Fourier transform unit that converts each block into a plurality of frequency domain signals by performing Fourier transform for each of the divided blocks; a coefficient multiplication unit that multiplies each of the converted plurality of frequency domain signals by each of a chromatic dispersion compensation coefficient and a window function or a value obtained by combining a dispersion compensation coefficient and a window function, and generates a coefficient-applied block obtained by summing multiplication results; an inverse Fourier transform unit that performs inverse Fourier transform on the generated coefficient-applied block; an overlap cut unit that removes a portion of the overlap from the converted coefficient-applied block, and generates an output signal; and a weighting coefficient optimization unit that optimizes the window function such that waveform distortion in a time domain is minimized on a basis of the generated output signal and an expected waveform obtained by performing chromatic dispersion compensation on the input signal.