Method and apparatus for achieving 180° phase invariant transmission in a PCM modem system
US6418170B1 · kind B1 · utility
4Cited by
9References
14Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Feb 7, 2000 |
| Grant date | Jul 9, 2002 |
| Priority date | — |
| Expiry date | Feb 7, 2020 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04B14/04
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
In a PCM modem system in which equivalence classes are used to communicate information from a transmitter to a receiver, a method is provided to solve the problem of 180° phase reversals in the communications channel which result in a garbled transmission. This is accomplished by remapping the equivalence classes into a form that can be differentially encoded and decoded such that equivalence class identity is not lost during a phase reversal of the channel.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.