Apparatus and methods for signal recovery in a digital communication system
US5841817A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 27, 1995 |
| Grant date | Nov 24, 1998 |
| Priority date | — |
| Expiry date | Oct 27, 2015 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L27/22
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
The present invention provides an apparatus and method for signal recovery from noisy observation in digital communication systems, utilizing a forward estimator and data smoother which improves the quality of the estimates of the transmitted signal. The present invention also provides an apparatus and method for the application of the forward estimator to the recovery of a digital data stream modulated with a CPM waveform, through the use of a receiver for GMSK demodulation. The digital data is first processed using the Forward Estimation process which calculates the probability that a symbol is in particular states. Bit decision is then applied, followed by scaling. The present invention further provides an apparatus and method for the application of the forward estimator and data smoother to the decoding of digital data which has been encoded with a Convolutional code. The digital data is first processed using the Forward Estimation procedure and then smoothed and scaled. Bit decision is then applied.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.