Encoding device and decoding device

• US 10,693,562 B2
• Filed: 10/16/2017
• Issued: 06/23/2020
• Est. Priority Date: 10/18/2016
• Status: Active Grant

• Current Assignee: Nippon Telegraph and Telephone Corporation
• Original Assignee: Nippon Telegraph and Telephone Corporation
• Inventors: Yamamoto, Shuto, Masuda, Akira, Sone, Yoshiaki, Fukutoku, Mitsunori
• Primary Examiner(s): Alagheband, Abbas H
• Application Number:
  US16/340,658
• Publication Number:
  US 20200052792A1
• Time in Patent Office: 981 Days
• Field of Search: 398 79
• CPC Class Codes: H04B 10/2507 for the reduction or elimination of distortion or dispersion
• CPC Class Codes: H04B 10/50 Transmitters
• CPC Class Codes: H04B 10/505 using external modulation
• CPC Class Codes: H04B 10/516 Details of coding or modulation
• CPC Class Codes: H04B 10/54 Intensity modulation
• CPC Class Codes: H04B 10/548 Phase or frequency modulation
• CPC Class Codes: H04J 13/12 Generation of orthogonal codes
• CPC Class Codes: H04J 13/18 Allocation of orthogonal codes
• CPC Class Codes: H04J 14/02 Wavelength-division multiplex systems
• CPC Class Codes: H04J 14/0227 Operation, administration, maintenance or provisioning [OAMP] of WDM networks, e.g. media access, routing or wavelength allocation
• CPC Class Codes: H04L 1/0041 Arrangements at the transmitter end
• CPC Class Codes: H04L 1/0045 Arrangements at the receiver end

Abstract

An encoding device includes an encoding unit, DA converters, light sources, intensity modulators, and wavelength multiplexers. The encoding unit adds (NM/2) to an encoded signal having a negative minimum value in a range of the encoded signal among encoded signals of N channels of (NM+1) values obtained by calculating an inner product of a Hadamard matrix of N rows and N columns and a matrix having elements of N intensity signals of (M+1) values. The DA converters of the channels convert the encoded signals of the channels from digital signals into electrical analog signals. The light sources output light of wavelengths for use in the channels. The light intensity modulators of the channels intensity-modulate the light output from the light sources with the encoded signals converted into the electrical analog signals by the DA converters. The wavelength multiplexer outputs a wavelength-multiplexed signal obtained by wavelength-multiplexing the light intensity-modulated by the light intensity modulators.

Claims

1. An encoding device, comprising:

an encoding unit configured to perform an encoding process of inputting N intensity signals (N is an integer greater than or equal to

     2) of (M+1) values (M is an integer greater than or equal to

     1) and adding (NM/2) to an encoded signal having a negative minimum value in a range of the encoded signal among encoded signals of N channels of (NM+1) values obtained by calculating an inner product of a Hadamard matrix of N rows and N columns and a matrix having elements of the N intensity signals;

N digital-to-analog conversion units corresponding to the N channels and configured to convert the encoded signals of the N channels from digital signals into electrical analog signals;

N light sources corresponding to the N channels and configured to output light of wavelengths for use in the N channels;

N light intensity modulation units corresponding to the N channels and configured to intensity-modulate the light output from the N light sources with the encoded signals converted into the electrical analog signals by the N digital-to-analog conversion units; and

a wavelength multiplexing unit configured to output a wavelength-multiplexed signal obtained by wavelength-multiplexing the light intensity-modulated by the N light intensity modulation units.

2. An encoding device, comprising:

an encoding unit configured to perform an encoding process of inputting N intensity signals (N is an integer greater than or equal to

     2) of (M+1) values (M is an integer greater than or equal to

     1) and adding (2^LM/2) (L is an integer less than or equal to 1 and 2^L is less than or equal to N) to an encoded signal having a negative minimum value in a range of the encoded signal among encoded signals of 2^L channels of (2^LM+1) values obtained by calculating an inner product of a Hadamard matrix of 2^L rows and 2^L columns and a matrix having elements of 2^L intensity signals included in a set for each set of 2^L intensity signals and generate encoded signals of N channels;

N digital-to-analog conversion units corresponding to the N channels and configured to convert the encoded signals of the N channels from digital signals into electrical analog signals;

N light sources corresponding to the N channels and configured to output light of wavelengths for use in the N channels;

N light intensity modulation units corresponding to the N channels and configured to intensity-modulate the light output from the N light sources with the encoded signals converted into the electrical analog signals by the N digital-to-analog conversion units; and

a wavelength multiplexing unit configured to output a wavelength-multiplexed signal obtained by wavelength-multiplexing the light intensity-modulated by the N light intensity modulation units.

3. The encoding device according to claim 2, wherein the 2^L intensity signals included in each set of intensity signals are selected so that variation in an average value of signal qualities of the 2^L intensity signals included in each set of intensity signals is minimized.

4. The encoding device according to claim 2, wherein, if L=1, an i^th set (i is an integer greater than or equal to 1 and less than or equal to N/2) among sets of signal intensities includes the intensity signal having i^th highest signal quality and the intensity signal having i^th lowest signal quality among the N intensity signals.