Frequency offset processing method, apparatus, and device and storage medium

Patent metadata

Field	Value
Publication number	US-11316591-B2
Application number	US-202117150661-A
Country	US
Kind code	B2
Filing date	Jan 15, 2021
Priority date	Jul 16, 2018
Publication date	Apr 26, 2022
Grant date	Apr 26, 2022

Abstract

A frequency offset processing method, apparatus, and a storage medium, where the method includes: determining a frequency offset of a preset channel in a wavelength selective switch (WSS); determining a correspondence between a frequency offset and a wavelength or a correspondence between a frequency offset and a pixel position based on the frequency offset of the preset channel; and determining a frequency offset of a traffic channel according to the determined correspondence.

First claim

What is claimed is:

1. A frequency offset processing method applied to a wavelength selective switch (WSS) comprising a switching engine and a plurality of channels, wherein each channel comprises at least one pixel column of the switching engine, and wherein the frequency offset processing method comprises:
determining a frequency offset of a preset channel in the WSS, wherein the preset channel comprises at least two channels other than a traffic channel among the plurality of channels;
determining, based on the frequency offset of the preset channel, a first correspondence between a first frequency offset and a wavelength or a second correspondence between a second frequency offset and a pixel position; and
determining a frequency offset of the traffic channel according to the first correspondence or the second correspondence.

2. The frequency offset processing method according to claim 1 , wherein the preset channel is for frequency offset monitoring and is distributed on two sides of the traffic channel, and wherein a pixel column in the preset channel is located in an edge position in the switching engine.

3. The frequency offset processing method according to claim 1 , wherein determining the frequency offset of the preset channel comprises determining detected frequency offsets of a plurality of subchannels in the preset channel, and wherein each subchannel comprises at least one pixel column.

4. The frequency offset processing method according to claim 3 , wherein determining the frequency offset of the preset channel in the WSS comprises:
determining a detected wavelength of each subchannel in the preset channel;
determining a calibration wavelength of each subchannel in the preset channel according to a preset correspondence between a subchannel and a wavelength; and
determining a detected frequency offset of each subchannel based on the detected wavelength of each subchannel and the calibration wavelength of each subchannel.

5. The frequency offset processing method according to claim 4 , wherein the detected wavelength of each subchannel is a detected center wavelength, wherein the switching engine is a liquid crystal on silicon (LCOS) chip, and wherein determining the detected wavelength of each subchannel in the preset channel comprises:
adjusting phase information of each subchannel so that a signal reflected by each subchannel is output to an output port of the WSS in a time division manner;
adjusting a center wavelength of a calibration light source entering each subchannel;
detecting a maximum optical power of the output port of the WSS; and
determining the detected center wavelength of each subchannel based on the maximum optical power.

6. The frequency offset processing method according to claim 4 , wherein the detected wavelength of each subchannel is an edge wavelength, wherein the switching engine is a liquid crystal on silicon (LCOS) chip, and wherein determining the detected wavelength of each subchannel in the preset channel comprises:
adjusting phase information of each subchannel so that a signal reflected by each subchannel is output to an output port of the WSS in a time division manner;
adjusting a center wavelength of a calibration light source entering each subchannel;
detecting a power of the output port of the WSS to generate a first filter spectrum of each subchannel;
comparing the first filter spectrum of each subchannel with a second filter spectrum of an adjacent subchannel; and
determining a wavelength with a same insertion loss or a wavelength at an intersection of the first and second filter spectra as the edge wavelength of each subchannel.

7. The frequency offset processing method according to claim 4 , wherein the detected wavelength of each subchannel is a detected center wavelength, wherein the switching engine is a micro-electro-mechanical system (MEMS) chip, and wherein determining the detected wavelength of each subchannel in the preset channel comprises:
adjusting a signal transmission direction corresponding to each subchannel so that a signal reflected by each subchannel is output to an output port of the WSS in a time division manner;
adjusting a center wavelength of a calibration light source entering each subchannel;
detecting a maximum optical power of the output port of the WSS; and
determining the detected center wavelength of each subchannel based on the maximum optical power.

8. The frequency offset processing method according to claim 4 , wherein the detected wavelength of each subchannel is an edge wavelength, wherein the switching engine is a micro-electro-mechanical system (MEMS) chip, and wherein determining the detected wavelength of each subchannel in the preset channel comprises:
adjusting a signal transmission direction corresponding to each subchannel so that a signal reflected by each subchannel is output to an output port of the WSS in a time division manner;
adjusting a center wavelength of a calibration light source entering each subchannel;
detecting a power of the output port of the WSS to generate a first filter spectrum of each subchannel;
comparing the first filter spectrum of each subchannel with a second filter spectrum of an adjacent subchannel; and
determining a wavelength with a same insertion loss or a wavelength at an intersection of the first and second filter spectra as the edge wavelength of each subchannel.

9. The frequency offset processing method according to claim 3 , wherein determining the first correspondence or the second correspondence comprises:
obtaining a fitted frequency offset of each subchannel based on a calibration wavelength of each subchannel or a pixel position of each subchannel, a preset frequency offset fitting formula, and at least one preset group of fitting coefficients of polynomials in the preset frequency offset fitting formula;
calculating a sum of squared errors between the fitted frequency offset of each subchannel and the detected frequency offset of each subchannel;
adjusting the fitting coefficients of the polynomials in the frequency offset fitting formula until a minimum sum of squared errors between a detected frequency offset of at least one subchannel and a fitted frequency offset of at least one subchannel is reached;
determining optimal fitting coefficients of monomials in the frequency offset fitting formula based on the minimum sum of squared errors; and
determining the first correspondence or the second correspondence based on the optimal fitting coefficients.

10. The frequency offset processing method according to claim 3 , wherein determining the first correspondence or the second correspondence comprises:
determining a frequency offset expression of each subchannel based on the detected frequency offset of each subchannel and one of a calibration wavelength of each subchannel or a pixel position of each subchannel;
solving equations of at least one frequency offset expression of at least one subchannel in the preset channel, to obtain fitting coefficients of polynomials in a frequency offset fitting formula; and
determining the first correspondence or the second correspondence based on the fitting coefficients.

11. A frequency offset processing device, comprising
one or more processors; and
a storage medium configured to store program instructions that, when executed by the one or more processors, cause the frequency offset processing device to:
determine a frequency offset of a preset channel in a wavelength selective switch (WSS) comprising a switching engine and a plurality of channels, wherein the preset channel comprises at least two channels other than a traffic channel among the plurality of channels;
determin

Assignees

• Huawei Tech Co Ltd

Inventors

• Jia Wei
• Pan Chao
• Zhao Han
• Deng Ning

Classifications

• H04Q2011/0026

  using free space propagation (e.g. lenses, mirrors) · CPC title

• H04B10/07955

  Monitoring or measuring power · CPC title

• H04B10/548 Primary

  Phase or frequency modulation · CPC title

• H04Q2011/0049

  Crosstalk reduction; Noise; Power budget · CPC title

• H04B10/572 Primary

  Wavelength control · CPC title