Frequency modulated message transmission
US4625318A · kind A · utility
16Cited by
4References
4Claims
0Family size
Assignee
Inventor
Key dates
| Filing date | Feb 21, 1985 |
| Grant date | Nov 25, 1986 |
| Priority date | — |
| Expiry date | Feb 21, 2005 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L27/2014
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
A data signal is encoded as frequency modulation by selecting carrier sources of different phases in response to data signals and filtering the resultant wave to produce an output deviating from the carrier frequency for one signal time in response to a single shift of phase. A phasing switch stores a record of the last sent phase and a record of the parity value of the number of zeros sent. The selected phase is as last sent for a 0, advanced for a 1 when the zero parity is of one value, and retarded when the zero parity is of another value.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.