Apparatus for estimating channel spacing, apparatus for monitoring wavelength, and receiver

A method for estimating channel spacing, including:

• measuring a spectrum gap width according to spectrum information of a received signal;
• and
• determining channel spacing by using the spectrum gap width according to a predefined corresponding relationship between channel spacing and the spectrum gap width,
• wherein the measuring the spectrum gap width according to the spectrum information of the received signal includes:
• acquiring the received signal;
• extracting the spectrum information from the received signal;
• and
• determining reference power according to a predefined reference power level, and setting a frequency difference between two frequency points in one of a left and right qap of a central channel in the spectrum information corresponding to the reference power level as the spectrum gap width.

A coherent optical receiver, comprising an apparatus for estimating channel spacing, configured to measure a spectrum gap width according to spectrum information of a received signal, and determine channel spacing by using the spectrum gap width according to a predefined corresponding relationship between the channel spacing and the spectrum gap width,

• wherein the apparatus for estimating channel spacing is configured to:
• acquire the received signal;
• extract the spectrum information from the received signal;
• and
• determine a reference power according to a predefined reference power level, and set a frequency difference between two frequency points in one of a left and right gap of a central channel in the spectrum information of the received signal corresponding to the reference power as the spectrum gap width.