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:
Nov. 24, 1998
Filed:
Dec. 29, 1995
Howard Zehua Chen, Berkeley Heights, NJ (US);
Lucent Technologies Inc., Murray Hill, NJ (US);
Abstract
A method and apparatus for implementation of a code division multiple access encoding scheme in a fiber-optic network. One preferred embodiment of the present invention provides an encoder and decoder for each terminal in the communications network, for example SONET OC-3, and allows each terminal to transmit their signals into the fiber-optic network at random. Because no time slot management is used, signals from all terminals interfere with one another. A coding technique is used by each decoder to sort its own signal out of this interference. The encoded data from each terminal is modulated with a technique known as MFSK (multiple frequency shift keying). The modulated signal is further used to intensity-modulate a semiconductor laser diode which may or may not be a single wavelength laser. At the receiver, the combined interference signal is first detected by a optical intensity detector and then sent to a frequency tone detectors which demodulate the MFSK signal. The output of the MFSK demodulator is then sent to a decoder where the original data bits are recovered. The network employs an optimum spread spectrum multiple access coding and modulation method that hops the subcarrier of a semiconductor laser diode over the entire range of DC -30 Ghz. Powerful concatenated Reed-Solomon outer, dual-K convolutional inner codes are used to minimize errors caused by mutual interference.