The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Dec. 13, 2016
Filed:
Nov. 21, 2014
Nippon Telegraph and Telephone Corporation, Tokyo, JP;
Koichi Ishihara, Yokosuka, JP;
Takayuki Kobayashi, Yokosuka, JP;
Riichi Kudo, Yokosuka, JP;
Yasushi Takatori, Atsugi, JP;
Munehiro Matsui, Yokosuka, JP;
Masato Mizoguchi, Yokosuka, JP;
Akihide Sano, Yokosuka, JP;
Shogo Yamanaka, Yokosuka, JP;
Etsushi Yamazaki, Yokosuka, JP;
Yutaka Miyamoto, Yokosuka, JP;
Eiji Yoshida, Yokosuka, JP;
Tadao Nakagawa, Yokosuka, JP;
Nippon Telegraph and Telephone Corporation, Tokyo, JP;
Abstract
To enable signal position detection, frequency offset compensation, clock offset compensation, and chromatic dispersion amount estimation in a communication system based on coherent detection using an optical signal, even on a signal having a great offset in an arrival time depending on a frequency due to chromatic dispersion. An optical signal transmitting apparatus generates specific frequency band signals having power concentrated on two or more specific frequencies and transmits a signal including the specific frequency band signals. An optical signal receiving apparatus converts a received signal into a digital signal, detects positions of the specific frequency band signals from the converted digital signal, estimates frequency positions of the detected specific frequency band signals, and detects a frequency offset between an optical signal receiving apparatus and an optical signal transmitting apparatus. Moreover, the optical signal receiving apparatus detects a clock offset between the optical signal receiving apparatus and the optical signal transmitting apparatus from an interval between the estimated frequency positions of the specific frequency band signals. Furthermore, the optical signal receiving apparatus estimates temporal positions of the detected specific frequency band signals and detects a chromatic dispersion amount from a difference between the temporal positions of the specific frequency band signals corresponding to different frequencies.