Full-duplex, sub-band spread spectrum communications system
US5025452A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 20, 1990 |
| Grant date | Jun 18, 1991 |
| Priority date | — |
| Expiry date | Mar 20, 2010 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04B1/707
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
An improved spread spectrum communications system is provided for establishing full-duplex voice/data radio communications within a single specified FCC ISM band. Spectrum spreading is performed relative to a plurality of sub-bands respectively defined about the lower and upper band-edges of the prescribed ISM band and having spectral roll-off characteristics which satisfy FCC requirements for radio frequency radiation outside the ISM bands on the corresponding band-edges thereof. Full-duplex operation is implemented by the use of digital MSK modulation and associated filtering in order to conserve available bandwidth and accommodate the filtered, modulated signal within the sub-bands defined in the prescribed ISM frequency band, and the system is capable of being easily interfaced to related digital communications services.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.