Digital receiver for variable data rate communications
US5612975A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 16, 1994 |
| Grant date | Mar 18, 1997 |
| Priority date | — |
| Expiry date | Jun 16, 2014 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L7/0029
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
A digital receiver includes a tuner and a demodulator that obtains a modulated signal carried in a received analog signal. A digital-to-analog converter operates at a preselected fixed sampling rate on the modulated signal to produce a first sequence of digitized samples. The first sequence of digitized samples is processed by a digital rotator to frequency-and phase-correct the first sequence of digitized samples. A controllable digital filter processes the first sequence to produce a filter output including a second sequence of digitized samples at a symbol rate. The second sequence is processed to ascertain a symbol rate of the modulated signal. The controllable filter coefficients are automatically varied to accommodate changes in the symbol rate of the modulated signal, so that the sampling rate of the digital-to-analog converter need not change. The second sequence is processed by post detection automatic gain control to produce a receiver output including a sequence of scaled and leveled digitized samples at the symbol rate.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.