Tetrahedron modem
US6700928B1 · kind B1 · utility
Assignee
Inventor
Key dates
| Filing date | May 11, 2000 |
| Grant date | Mar 2, 2004 |
| Priority date | — |
| Expiry date | May 11, 2020 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L2027/0055
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
A tetrahedron modem phase modulates input serial binary data and demodulates input waveforms based on a four dimensional vector set. The phase modulation scheme has four possible state vectors (or symbols), that form a tetrahedron in four dimensional space. This symbol geometry improves the bit error rate performance over conventional PSK methods for a given signal to noise ratio. In addition the tetrahedron modem aids bit synchronization and eliminates phase ambiguity in the receiver. Lastly, the tetrahedron modulator outputs a constant envelope waveform, which may be subjected to non-linear devices and channels without fear of negative effects due to amplitude distortion.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.