Block coding scheme for fractional-bit transmission
US5113401A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 30, 1989 |
| Grant date | May 12, 1992 |
| Priority date | — |
| Expiry date | Aug 30, 2009 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L27/3477
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
In a trellis-coded modulation (TCM) transmission system, data bits are grouped into bit blocks (13), and each such bit block is encoded to select a fixed number w of symbols from a given symbol set (14). The symbols are subdivided into subsets, and each subset includes a few outer symbols and a greater number of inner symbols. Each symbol represents one particular transmission signal value. A first portion (17) of each bit block is separated into w bit subgroups, each of which is separately expanded by a convolutional encoder (20) to obtain a bit combination (19, 15) for specifying one of the symbol subsets. The remaining portion (21) of each bit block is expanded by a block coder (22) to obtain w bit subgroups (23), each being a bit combination (25, 16) for selecting one particular symbol out of a specified subset; outer symbols are selected less frequently than inner symbols. The arrangement allows to transmit a non-integer number of data bits per symbol, and further allows to operate with single-symbol TCM.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.