Demodulator for an HDTV receiver
US6356598B1 · kind B1 · utility
Assignee
Inventor
Key dates
| Filing date | Aug 26, 1998 |
| Grant date | Mar 12, 2002 |
| Priority date | — |
| Expiry date | Aug 26, 2018 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N21/426
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A receiver for processing a VSB modulated signal containing terrestrial broadcast high definition television information and a pilot component includes an input analog-to-digital converter (19) for producing a datastream which is oversampled at twice the received symbol rate, and a digital demodulator (22; FIG. 3) with a data reduction network (330, 332) in a phase control loop. A segment sync detector (24; FIG. 4, 5) uses an abbreviated correlation reference pattern to recover a twice symbol rate sampling clock for the digital converter (19). A DC offset associated with the pilot component is removed (26; FIG. 6) from the demodulated signal before it is applied to an NTSC interference detection network (30; FIG. 7). The interference detection network includes a comb filter network (710, 718) responsive to a twice symbol rate sampled data datastream, and exhibits a sample delay dimensioned to avoid aliasing in the combed frequency spectrum (FIG. 8), thereby increasing the effectiveness of NTSC co-channel interference detection.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.