Data coding method for use in digital communication systems
US4924463A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 24, 1989 |
| Grant date | May 8, 1990 |
| Priority date | — |
| Expiry date | Jul 24, 2009 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04J3/0605
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
A data coding method for digital communication systems is disclosed. In two embodiments, every four bits of data in a first data channel are mapped to a five bit code symbol. The five bit code symbols are chosen to have a duty cycle of 40 to 60 percent. In the first embodiment, a second channel of data is optionally interleaved with the encoded first channel data by placing single bits from the second channel every sixth bit in the data stream between each five bit code symbol. A plurality of synchronizing words are each formed from other pairs of five bit code symbols, and, in the two channel embodiment, the optional two bits of data from the second channel. The synchronizing words also have a duty cycle of 40 to 60 percent, and further have the characteristic that their bit patterns can only occur where they are placed in a stream of encoded data. This enables them to be easily recognized in a data stream for both synchronization of a communication element with the encoded data stream, and conveyance of control information between elements in the system. The second channel can also be utilized for conveyance of control information, as a separate data channel, or in a third embodi…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.