In-band-on-channel (IBOC) system and methods of operation using orthogonal frequency division multiplexing (OFDM) with timing and frequency offset correction
US6961393B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Jul 14, 1999 |
| Grant date | Nov 1, 2005 |
| Priority date | — |
| Expiry date | Jul 14, 2019 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L27/2647
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
An OFDM receiver recovers an rf signal as in-phase (I) and quadrature phase (Q) components of a baseband signal sampled in an A/D converter. The I and Q components of a received symbol are correlated at all sampling points. Correlation values are averaged over the latest L frames and saved in an L-deep FIFO. Symbol amplitude and phase are computed and passed to an offset estimator and an OFDM frame synchronization estimator. A phase-locked loop oscillator provides a sample number identifying the OFDM frame boundary to the offset estimator. An estimated offset value is selected as the negative of the phase angle of the auto correlation.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.