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:
May. 23, 2000
Filed:
Jun. 26, 1997
Akihiro Kanazawa, Tokyo, JP;
NEC Corporation, , JP;
Abstract
It is the object of the invention to provide a sub-carrier multiplexed optical signal transmission system employing super wide-band frequency modulation scheme, in which the SNR of a sub-carrier of a higher sub-carrier frequency is not decreased. The intensity of a sub-carrier of a higher sub-carrier frequency is increased by a pre-emphasizer, and modulated in a FM modulator. Then, a super wide-band FM signal is obtained. The super wide-band FM signal is supplied to the transmitter laser diode, and intensely modulated to obtain an optical signal. The optical signal is transmitted through an optical fiber, supplied to an optical receiver and converted into an electrical signal. The super wide-band FM signal thus obtained is demodulated by a FM demodulator. The sub-carrier multiplexed signal is supplied to a de-emphasizer having an inverse characteristic of that of the pre-emphasizer, wherein the signal supplied thereto recovers its original frequency spectrum.