Digital signal communication system for multi-level modulation including unique encoder and decoder
US4523323A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Feb 11, 1983 |
| Grant date | Jun 11, 1985 |
| Priority date | — |
| Expiry date | Feb 11, 2003 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L27/18
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
A digital signal communication system has a transmitter for differentially converting first digital signals of n trains (n is an integer of 3 or larger) into a second digital signal of n trains comprising a plurality of words. Responsive to the second digital signals, a modulated signal is provided with 2.sup.n (=N) modulation levels, which are transmitted. A receiver responds to the modulated signals, and demodulates them to provide signals of n trains corresponding to the second digital signals. This demodulated signal is differentially converted to provide n trains of signals corresponding to the first digital signals. The Hamming distance between two words of said second digital signals corresponding to the adjacent two modulation levels is either 1 or 2 and the numbers of the Hamming distances of 1 and 2 equal N/2, respectively.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.