Coding and decoding system with multi-level format
US3988676A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Feb 20, 1975 |
| Grant date | Oct 26, 1976 |
| Priority date | — |
| Expiry date | Feb 20, 1995 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L25/4919
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
The present invention is directed to a method and apparatus for coding and decoding data so that it may be transmitted from point to point in either a baseband system or in a carrier system. The method and apparatus involves forming a multi-bit group of binary signals (bits) and transmitting such signals with at least one bit and a fractional part of another bit of the group in an encoding period. In a preferred embodiment of my invention a pair of adjacent encoding periods are employed to fully identify all the bits of a multi-bit group. My format requires less bandwidth than prior art binary formats. Furthermore, my format, when employed with a three level system, also requires less bandwidth than any known prior art three level system. The invention also includes an inherent error detection capability. Such inherent error detection is utilized at the receiver to automatically emit a decoded signal which has a high probability of being the correct signal that was transmitted. In addition, the invention readily provides a signal of a unique characteristic from which a decoding clock can be simply and easily derived.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.