Optical Receiver Burst Sampling with Preamble Phase Interpolation
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Solution Overview
Problem
In high-speed optical transmission networks, the sampling phase deviation in optical receivers leads to a decrease in signal-to-noise ratio and an increase in bit errors due to out-of-sync burst packet arrivals and varying transmission delays, which are not effectively addressed by existing technologies.
Innovation Solution
A signal sampling method and apparatus that involves sampling a received burst signal at a first frequency, interpolating the preamble signal at a second frequency, and determining the phase difference between the burst signal and the local sampling clock to achieve accurate sampling, using discrete Fourier transform and interpolation techniques to minimize phase jitter and improve synchronization.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If the ADC samples the burst packet signal according to the local clock, then the sampling process is simple and straightforward, but the sampling phase deviates because the burst packet arrival phase is inconsistent with the local sampling clock phase
Solution Approach 1:
The patent performs preliminary actions by estimating the phase difference between the burst packet signal and local sampling clock before actual sampling, and pre-calculating compensation values. The equalization filter is configured in advance with compensation coefficients to correct sampling phase deviation, ensuring accurate sampling without complex real-time adjustments.
Solution Approach 2:
The patent implements feedback by estimating the phase difference between the burst packet signal and local sampling clock, then using this information to adjust the sampling process. The system continuously monitors and compensates for phase deviations, creating a closed-loop control mechanism that maintains sampling accuracy despite varying arrival times.
2Reliability
If the sampling is performed at the optimal position of the symbol, then the signal energy of sampled data is maximized, but this requires precise synchronization that is difficult to achieve due to varying transmission delays
Solution Approach 1:
The patent changes parameters by adjusting the equalization filter coefficients based on estimated phase differences. Instead of complex timing adjustments, the system modifies the filter parameters (compensation coefficients) to adapt to different arrival times and phase deviations, simplifying the synchronization process while maintaining optimal sampling.
Solution Approach 2:
The patent introduces an intermediary element - the equalization filter with compensation coefficients - that mediates between the varying arrival times and the sampling process. This filter acts as a buffer that corrects phase deviations without requiring direct complex synchronization between the burst packet clock and local sampling clock.
3Adaptability or versatility
If different ONUs send burst packets through different transmission distances, then the system supports multiple users with different link characteristics, but the link damage to burst packet signals varies causing different delays
Solution Approach 1:
The patent applies local quality by providing customized compensation for each ONU's burst packets. The equalization filter is configured with specific compensation coefficients tailored to each user's transmission characteristics and phase deviation, allowing each signal to be optimally corrected according to its specific path conditions.
Solution Approach 2:
The patent implements dynamics by making the equalization filter adaptive and reconfigurable. The compensation coefficients are dynamically adjusted based on the estimated phase difference for each burst packet, allowing the system to adapt to varying transmission distances, delays, and phase deviations from different ONUs.
Data Source
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AI summary
The present disclosure provides a signal sampling method and apparatus, and an optical receiver. The method includes sampling a burst signal that is received according to a first sampling frequency to obtain a first sampling signal; sampling a preamble signal in the first sampling signal according to a second sampling frequency to obtain a second sampling signal; determining a phase difference between the burst signal and a local sampling clock corresponding to the first sampling frequency according to the second sampling signal; and interpolating the first sampling signal according to the phase difference to obtain a target sampling signal.