Pilot Tone Spur Removal and Power Compensation
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Solution Overview
Problem
In dense wavelength division multiplexed (DWDM) systems, pilot tones used for optical performance monitoring are often interfered with by spectral spurs, leading to challenges in decoding accuracy and efficiency due to noise and interference from high-speed data channels, especially when carrying payloads like AIS or PRBS.
Innovation Solution
An optical receiver is configured with a spurs removal component that identifies and removes spectral spurs in the frequency domain from the pilot-tone spread signal, followed by a power compensation mechanism to correct for potential signal loss, ensuring accurate decoding of the pilot tone.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If spectral spurs are removed from the pilot-tone spread signal, then decoding accuracy is improved, but signal power is reduced due to inadvertent removal of normal signal parts
Solution Approach 1:
The patent extracts and removes spectral spurs from the pilot-tone spread signal in the frequency domain before decoding. A spurs removal component identifies spectral spurs and removes them, separating the harmful interference from the useful signal to improve decoding accuracy while minimizing loss of normal signal parts
Solution Approach 2:
The patent changes parameters by calculating a power compensation ratio factor that compensates for power loss during spur removal. The power correction component applies this ratio to adjust the signal power, transforming the signal parameters to maintain adequate power levels after spur removal
2Object-affected harmful factors
If a predetermined range of spectra is removed around detected peaks, then spectral spur interference is reduced, but normal signal components may be inadvertently removed
Solution Approach 1:
The patent applies local quality by removing spectra only in localized regions around detected peak frequencies rather than applying uniform removal across the entire spectrum. This targeted approach removes spurs at specific frequency locations while preserving normal signal components in other regions
Solution Approach 2:
The patent uses partial action by removing only a predetermined small range of spectra around each detected peak rather than removing entire frequency bands. This partial removal is sufficient to eliminate spurs while minimizing removal of useful signal content
Data Source
AI summary
Embodiments can provide spurs removal in a pilot-tone spread signal. For achieving this, at least one peak in the pilot-tone spread signal may be found. A predetermined small range of the spectra power around the at least one peak may be removed. In some situations, the removal of the spurs in the pilot-tone spread signal may result in inadvertent removal of a normal part of the pilot-tone spread signal. For addressing this, a power ratio between the spectrum of the pilot-tone spread signal before the removal and after the removal can be calculated. For accounting for the power loss due to the spurs removal, this power ratio can be applied to the pilot-tone spread signal after the removal to obtain a corrected pilot-tone spread signal.