Rotationally invariant pragmatic trellis coded digital communication system and method therefor
US5995551A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 15, 1997 |
| Grant date | Nov 30, 1999 |
| Priority date | — |
| Expiry date | Aug 15, 2017 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L27/186
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
A communication system (10) includes a rotationally invariant pragmatic trellis coded modulator (18) and demodulator (34). The modulator (18) partitions information bits (20) into primary (42) and secondary (44) data streams. The secondary data stream (44) is convolutionally encoded (70) then fed to the LSB of a phase mapper (76). The phase mapper (76) is arranged so that all pairs of adjacent phase data are generated from pairs of opposing polarity LSB inputs. The primary data stream (42) is differentially encoded through a dual channel differential encoder (50). The demodulator (34) convolutionally decodes (90) the secondary stream, then re-encodes (96) secondary stream estimates. The re-encoded secondary stream estimates are used to remove (102) the secondary modulation from phase value estimates. Adjusted phase value estimates are phase demodulated (104) and differentially decoded using a dual channel differential decoder (106).
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.