Optical Receiver Clock Synchronization Using LUT-Based Delay Compensation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional optical receivers require increased circuit scale and power consumption for clock synchronization due to the need for FIR filters to adjust delay.
Innovation Solution
The optical receiver employs a method to detect the clock phase in the time domain, estimate clock frequency differences, and use a lookup table to select filter coefficients for compensating wavelength dispersion and delay, eliminating the need for FIR filters and multipliers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If FIR filters are used to adjust delay for clock synchronization, then clock synchronization accuracy is improved, but circuit scale and power consumption increase
Solution Approach 1:
The patent extracts the delay adjustment function from the traditional FIR filter structure and implements it separately using a delay adjustment unit. This separation allows the main signal processing to use a smaller filter while delay adjustment is handled independently, reducing overall power consumption while maintaining synchronization accuracy.
Solution Approach 2:
The patent segments the signal processing into distinct functional units: a reduced-order FIR filter for basic processing and a separate delay adjustment unit for precise timing. This segmentation allows each component to be optimized independently, reducing the total circuit scale and power consumption compared to a single large FIR filter.
2Measurement precision
If FIR filters are used to adjust delay for clock synchronization, then clock synchronization accuracy is improved, but device complexity increases
Solution Approach 1:
The patent extracts the delay adjustment function from the traditional FIR filter structure and implements it separately using a delay adjustment unit. This separation allows the main signal processing to use a smaller filter while delay adjustment is handled independently, reducing overall circuit scale while maintaining synchronization accuracy.
Solution Approach 2:
The patent segments the signal processing into distinct functional units: a reduced-order FIR filter for basic processing and a separate delay adjustment unit for precise timing. This segmentation allows each component to be optimized independently, reducing the total circuit scale and complexity compared to a single large FIR filter.
3Adaptability or versatility
If multiple clock sources are mounted on the optical transceiver for communication with multiple communicating parties, then communication capability with multiple parties is improved, but device complexity increases
Solution Approach 1:
The patent implements a universal resampling unit that can handle clock synchronization for multiple communicating parties using a single clock source. This multi-functional unit replaces the need for multiple dedicated clock sources, maintaining communication capability with multiple parties while reducing device complexity and configuration overhead.
Data Source
Figure 1
Figure 2
Figure 3
AI summary
An optical receiver (1) detects a clock phase of a signal in a time domain whose number of samples has been adjusted, estimates a clock frequency difference from a received signal using a detection value of the clock phase, determines a sampling phase for each FFT depending on an estimation value of the clock frequency difference, selects from a coefficient LUT a filter coefficient associated with a delay amount corresponding to the sampling phase, and multiplies a signal divided by a division unit with the selected filter coefficient.