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. 30, 2000
Filed:
Sep. 04, 1997
Erwin Schlag, Vaihingen, DE;
Alcatel, Paris, FR;
Abstract
In a digital optical transmission system, such as a passive optical distribution network, analog electric signals, e.g., video signals, are to be optically transmitted in such a way that they can be recovered in a receiver (BONT) in a simple manner. To accomplish this, the transmitter of the transmission system includes a delta-sigma modulator (MOD) and an electrical-to-optical transducer (EO). The delta-sigma modulator (MOD) digitizes the analog electric signals using the delta-sigma modulation method. The electrical-to-optical transducer (EO) then converts the digitized signals to optical signals, which are transmitted over optical fibers to a plurality of receivers (BONT). To recover the analog electric signals, each receiver (BONT) requires only one optical-to-electrical transducer (OE) and one passive electric filter (FIL). The filter (FIL) is a passive low-pass filter in one case and a passive bandpass filter in another. Appropriate selection of the sampling frequency for the delta-sigma modulation and utilization of image frequencies for transmission eliminate the need for frequency translators in the receivers (BONT).