Digital broadcast receiver
US6148045A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 14, 1999 |
| Grant date | Nov 14, 2000 |
| Priority date | — |
| Expiry date | Sep 14, 2019 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L1/0054
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
To control the oscillation frequency of a local oscillator, a digital broadcast receiver demodulates a phase-reference symbol contained in an orthogonal frequency-division multiplexed broadcast signal, modifies the resulting frequency-domain data by multiplication with complex conjugates of known data encoded in the phase-reference signal, under different assumed frequency offsets, converts the modified data to time-domain data, and thereby detects a first frequency error equal to a multiple of the subcarrier spacing and a second frequency error not exceeding the subcarrier spacing. Differential phase error is also detected. The oscillation frequency is adjusted to correct the first frequency error and differential phase error; then the second frequency error is used to correct for ambiguity in the differential phase error.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.