Data coding system
US5502744A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Aug 4, 1993 |
| Grant date | Mar 26, 1996 |
| Priority date | — |
| Expiry date | Aug 4, 2013 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L25/4917
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
A system for communicating digital data comprises a splitting device (38) for separating an input digital data word, which may be provided by a speech coding arrangement (34,36), into most significant bits and less significant bits. The most significant bit(s) of the digital data word are encoded (40) using a robust signalling alphabet and less significant bit(s) are encoded (42,44) using progressively less robust signalling alphabets. All of the symbols resulting from the encoding are combined (46) and transmitted (48). On reception (50) the received signal is split (52) and demodulated (54,56,58) to provide respective portions of a received data word to a combining means (60). Where the data word was originally provided by speech coding arrangement the received data word may be provided to a resynthesising arrangement (62,64). The signalling alphabets may comprise 2-level modulation, 3,4 and 8-level modulation and/or phase modulation of various degrees.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.