Frequency synchronization apparatus and method for OFDM systems
US7133479B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Apr 15, 2003 |
| Grant date | Nov 7, 2006 |
| Priority date | — |
| Expiry date | May 26, 2025 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L27/2675
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
A frequency synchronization apparatus and method for OFDM systems. The frequency synchronization apparatus is comprised of a digital mixer, a first synchronizer and a second synchronizer. The digital mixer acquires a baseband signal by means of a local frequency and adjusts the local frequency in response to an integer frequency offset and a fractional frequency offset. The first synchronizer takes a sequence of received samples derived from the baseband signal in a time domain to estimate the fractional frequency offset. The fractional frequency offset is fed back to the digital mixer. After that, the second synchronizer takes a sequence of demodulated symbols derived from the baseband signal in a frequency domain. The second synchronizer yields the integer frequency offset through a coarse search stage and a fine search stage. Then, the integer frequency offset is fed back to the digital mixer.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.