Method for increasing the dynamic range of a signal in a simultaneous voice and data system by the use of overlapping signal point regions and trellis coding
US5521942A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 14, 1993 |
| Grant date | May 28, 1996 |
| Priority date | — |
| Expiry date | Jun 14, 2013 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L27/3483
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
A communications system simultaneously transmits both a primary data signal and a secondary voice signal in such a way that the dynamic range of the secondary voice signal is increased even though deliberate errors are introduced into the transmitted data portion of the signal. In particular, the communications system includes an error correcting technique like channel encoding and the constellation signal space is divided into a number of regions, where at least one of the regions overlaps with another region. The primary signal is channel encoded to select a particular one of the number of regions, the region being represented by a reference signal point value. The voice signal is encoded to provide a signal point vector, which is added to the reference signal point in such a way that the resultant signal point is located in the overlapping region thereby deliberately introducing an error into the resulting transmitted signal point stream. Notwithstanding the deliberately introduced error, the channel encoding of the primary signal allows a receiver to recover the originally selected reference signal point value, which when subtracted from the received signal point value approxim…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.