Differential encoder and decoder for transmitting binary data
US4562425A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jan 20, 1983 |
| Grant date | Dec 31, 1985 |
| Priority date | — |
| Expiry date | Jan 20, 2003 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L27/362
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
To enable binary data to be differentially encoded into symbols (waves) for transmission the data is applied in n-bit data-words to produce symbols which, when displayed in a phasor-diagram, are in three groups in three 120.degree.-phase-sectors respectively, the number and dispositions of the symbols in the three sectors being the same. The encoding is such that, depending upon the data-word to be transmitted the sector in which a symbol is produced is rotated by 0.degree., 120.degree. or 240.degree. relative to the next preceding sector containing a symbol. In some embodiments one of the 2.sup.n possible different data-words is applied to produce an absolute symbol of zero amplitude. At a receiver the received symbols are decoded having regard to the 0.degree., 120.degree. and 240.degree. differential sector-rotations.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.