Method and apparatus for time and frequency synchronization of OFDM communication systems
US7027429B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jun 19, 2001 |
| Grant date | Apr 11, 2006 |
| Priority date | — |
| Expiry date | Nov 13, 2023 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L27/2675
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
A method and apparatus for joint time and frequency synchronization for orthogonal frequency division multiplexing (OFDM) systems. A multitone pilot signal is sent in a designated OFDM symbol period. The receiver synchronizes to the pilot signal in a two-stage procedure. The first stage estimates the frequency offset coarsely with a frequency-domain correlation method and estimates the time offset with smoothed time-domain correlation. In a multipath channel, the smoothed time offset estimate is used to locate a cyclic prefix interval which captures the maximum total signal energy. The second stage improves the frequency estimate with a computationally efficient numerical optimization method.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.