Apparatus and method for a high throughput fiber-optic access network using code division multiple access
US5841776A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Dec 29, 1995 |
| Grant date | Nov 24, 1998 |
| Priority date | — |
| Expiry date | Dec 29, 2015 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L2012/5675
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
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 subca…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.