Optical cable television transmission system
US5162937A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jan 15, 1991 |
| Grant date | Nov 10, 1992 |
| Priority date | — |
| Expiry date | Jan 15, 2011 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04J14/0298
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
The invention is based on the problem of transmitting a frequency-division multiplex signal occupying a board frequency band, e.g., the cable television frequency band of 47-440 MHz, over an optical waveguide transmission section. According to the invention, in the transmitting unit, the whole frequency band to be transmitted is divided into two sub-bands (FB.sub.1, FB.sub.2), and the lower sub-band (FB.sub.1) is converted by means of single-sideband amplitude modulation of a high-frequency carrier (f.sub.0) into a higher-frequency transmission frequency band, e.g. 497-688 MHz, which is less than one octave in width, based on its lowest frequency. The lower sub-band (FB.sub.1) and the transmission frequency band produced by the conversion are converted separately into optical signals with different wavelengths (.lambda..sub.1, .lambda..sub.2) and are transmitted in a wavelength multiplex procedure via the optical waveguide. Because of the limitation of less than one octave, second-order intermodulation products, which are usually formed during conversion into an optical signal, fall into unoccupied frequency regions. A corresponding reverse processing is carried out on the receivin…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.