Title:
OPTICAL MODULATION/DEMODULATION METHOD, OPTICAL COMMUNICATION SYSTEM, OPTICAL TRANSMITTING DEVICE AND OPTICAL RECEIVING DEVICE
Document Type and Number:
WIPO Patent Application WO/2019/176978
Kind Code:
A1
Abstract:
The purpose of the present invention is to provide an optical modulation/demodulation method, an optical communication system, an optical transmitting device and an optical receiving device with which it is possible to suppress a rise in cost and a reduction in bandwidth during service multiplexing. An optical transmitter according to the present invention establishes in advance that bit rates have a relationship of an integral multiple of 2 or more each other and an amplitude is reduced in correspondence to an increase in the bit rate, and adds up a plurality of binary signals in which rise and fall timings are synchronized, generates a multi-value signal and modulates light from one light source. This means that it is possible to multiplex a number of services by one transmitter by generating a multi-value signal as a modulating signal. For an optical signal in which services are multiplexed by the optical transmitting device, the optical receiving device according to the present invention has had a plurality of thresholds set with which it is possible to discriminate all amplitude values of a multi-value signal and compares the amplitude of a multi-value signal that is photoelectrically converted from the received optical signal with the plurality of thresholds. The present optical receiving device determines the bits of a binary signal that is multiplexed on the basis of the result of comparison.
Inventors:
HARA KAZUTAKA (JP)
HONDA KAZUAKI (JP)
HONDA KAZUAKI (JP)
Application Number:
PCT/JP2019/010150
Publication Date:
September 19, 2019
Filing Date:
March 13, 2019
Export Citation:
Assignee:
NIPPON TELEGRAPH & TELEPHONE (JP)
International Classes:
H04B10/54; H04B10/69; H04J3/00; H04L25/49
Domestic Patent References:
| WO2008132119A1 | 2008-11-06 |
Foreign References:
| EP1420532A1 | 2004-05-19 | |||
| US5510919A | 1996-04-23 | |||
| JPH08251139A | 1996-09-27 |
Other References:
KRIMMEL, HEINZ G. ET AL.: "10 Gbps / 2. 5Gbps GPON Coexistence by Downstream Bit-Stacking", ECOC 2008, 2008, XP031381138
Attorney, Agent or Firm:
OKADA, Kenji et al. (JP)
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