Communication scheme using non-coherent frequency detection of trellis-based coding of plural transmission frequencies per baud
US5926508A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Feb 21, 1995 |
| Grant date | Jul 20, 1999 |
| Priority date | — |
| Expiry date | Feb 21, 2015 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04B7/18528
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
A reduced cost, robust data communication scheme for very small aperture terminal satellite communication systems combines non-coherent frequency detection and trellis-coded, multi-frequency modulation. The data code width is associated with the size of a multiple frequency set and the selection of a given combination of frequencies for transmission during a respective baud. One portion the data is convolutionally encoded and points to an orthogonal signal set associated with frequencies of a partitioned multiple frequency set. Another portion of the data identifies the frequency combination within the group pointed to by the one portion. The combined portions encode a multi-frequency transmission waveform. At the receiver, the multi-frequency tone sequence is detected by non-coherent frequency detection. For each baud, matched filters output a most likely set of frequencies transmitted during that baud, as soft decisions to a Viterbi decoder.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.