Demodulator alignment method and apparatus
US5315262A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Sep 4, 1992 |
| Grant date | May 24, 1994 |
| Priority date | — |
| Expiry date | Sep 4, 2012 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03J2200/28
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A demodulator alignment method and apparatus (400) employs an alignment signal generator (401-405) to generate an alignment signal (417) in response to a modulation reference signal (413). The alignment signal (417) is demodulated by a demodulator circuit (402), having a voltage controlled delay element (404) to produce a demodulated alignment signal (419) having distortion components. The demodulated alignment signal (419) is then coupled to a filter (406) which isolates the distortion components. A detector (408) is then employed to detect the isolated distortion components. Next, an error amplifier (410) compares the detected distortion to a reference (430), generates an error signal (450) and applies the error signal (450) to a sampling circuit (412). The sampling circuit (412) samples the error signal (450) and applies the sampled error signal (460) to the voltage controlled delay element (404) as a correction voltage in order to minimize the distortion components at the demodulator output (419) during data recovery.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.