Optical multiplexing device and method of generating optical OFDM signal

Patent metadata

Field	Value
Publication number	US-9602201-B2
Application number	US-201514672527-A
Country	US
Kind code	B2
Filing date	Mar 30, 2015
Priority date	May 15, 2014
Publication date	Mar 21, 2017
Grant date	Mar 21, 2017

Abstract

An optical multiplexing includes: a monitor configured to detect power of an optical component including a frequency component of a cross point between spectra of a first sub-carrier signal and a second sub-carrier signal; and a controller configured to control a modulation timing of a data symbol of the second sub-carrier signal according to the power detected by the monitor, wherein the second sub-carrier signal is multiplexed to a carrier to be adjacent to the first sub-carrier signal multiplexed to the carrier so as to generate an optical Orthogonal Frequency Divisional Multiplexing (OFDM) signal in which an interference between the first and second sub-carrier signals is suppressed.

First claim

What is claimed is:

1. An optical multiplexing device comprising:
a monitor configured to detect power of an optical component including a frequency component of a cross point between spectra of a first sub-carrier signal and a second sub-carrier signal; and
a controller configured to control a modulation timing of a data symbol of the second sub-carrier signal according to the power detected by the monitor,
wherein the second sub-carrier signal is multiplexed to a carrier to be adjacent to the first sub-carrier signal multiplexed to the carrier so as to generate an optical Orthogonal Frequency Divisional Multiplexing (OFDM) signal in which an interference between the first and second sub-carrier signals is suppressed.

2. The optical multiplexing device according to claim 1 ,
wherein the monitor includes
an optical filter configured to extract the optical component including the frequency component of the cross point between the spectra of the first sub-carrier signal and the second sub-carrier signal, and
a photodetector configured to detect power of the optical component transmitted through the optical filter.

3. The optical multiplexing device according to claim 2 ,
wherein the first sub-carrier signal and the second sub-carrier signal are respectively modulated at a symbol rate having a predetermined frequency spacing based on a data signal to be transmitted, and
wherein the optical filter extracts the optical component having a bandwidth of the symbol rate or less.

4. A method of generating an optical Orthogonal Frequency Divisional Multiplexing (OFDM) signal, the method comprising:
detecting an optical component including a frequency component of a cross point between spectra of a first sub-carrier signal and a second sub-carrier signal; and
controlling a modulation timing of a data symbol of the second sub-carrier signal according to the detected power so that the second sub-carrier signal is multiplexed to a carrier to be adjacent to the first sub-carrier signal multiplexed to the carrier to generate the OFDM signal in which an interference between the first and second sub-carrier signals is suppressed.

5. The method of generating an optical OFDM signal according to claim 4 , further comprising:
extracting the optical component including the frequency component of the cross point between the spectra of the first sub-carrier signal and the second sub-carrier signal; and
detecting power of the extracted optical component.

6. The method of generating an optical OFDM signal according to claim 5 ,
wherein the first sub-carrier signal and the second sub-carrier signal are respectively modulated at a symbol rate having a predetermined frequency spacing based on a data signal to be transmitted, and
wherein the optical component having a bandwidth of the symbol rate or less is extracted.

7. An apparatus for generating an optical Orthogonal Frequency Divisional Multiplexing (OFDM) signal, the apparatus comprising:
means for detecting an optical component including a frequency component of a cross point between spectra of a first sub-carrier signal and a second sub-carrier signal; and
means for controlling a modulation timing of a data symbol of the second sub-carrier signal according to the detected power so that the second sub-carrier signal is multiplexed to a carrier to be adjacent to the first sub-carrier signal multiplexed to the carrier to generate the OFDM signal in which an interference between the first and second sub-carrier signals is suppressed.

Assignees

• Fujitsu Ltd

Inventors

• Okabe Ryou
• Watanabe Shigeki

Classifications

• H04B10/5057 Primary

  using a feedback signal generated by analysing the optical output · CPC title

• H04J14/02

  Wavelength-division multiplex systems · CPC title

• H04B10/07955 Primary

  Monitoring or measuring power · CPC title

• H04J14/0298

  with sub-carrier multiplexing [SCM] · CPC title

• H04B10/548

  Phase or frequency modulation · CPC title