System and method for split phase demodulation of frequency shift keyed signals
US5420888A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 21, 1992 |
| Grant date | May 30, 1995 |
| Priority date | — |
| Expiry date | May 21, 2012 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L27/1525
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
A system and method for efficient operation of a digital signal processor allows execution of a noncoherent FSK demodulation process at the baud rate of the incoming signal. First and second signal detecting channels terminate at a summing junction. A signal sampler for applying a sampled signal to the first and second signal detecting channels. The first and second signal detecting channels each include, in series, a finite impulse response filter for filtering out energy outside a selected bandwidth, automatic gain control and a demodulator. The finite impulse response filter means for the second signal detecting channel further shifts the phase of the sampled signal in the second signal detecting channel approximately 90 degrees relative to the sampled signal in the first signal detecting channel. The demodulator in each signal detecting channel further includes first and second sampled signal transmission paths terminating in a multiplying junction. The first signal transmission path in each demodulator includes a tunable delay line. The decoder takes its input from the summing junction for reproducing a signal indicating presence of a particular frequency or reproduction of th…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.