Method and apparatus for synchronization in digital transmisison systems of the OFDM type
US5652772A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jan 22, 1996 |
| Grant date | Jul 29, 1997 |
| Priority date | — |
| Expiry date | Jan 22, 2016 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L5/0048
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
The invention relates to a method and apparatus for synchronization of transmitters and receivers in digital transmission systems of the OFDM type. The system uses FFT technique to carry out the modulation and demodulation procedures. According to the invention, the transmitter sends synchronization frames with known frequencies and phase positions and with known time intervals in certain time slots. The receiver carries out a series of time-shifted FFT operations over the time position where the synchronization frame is calculated to be. For each operation, a cross-correlation is carried out in the frequency plane of the output signal with the known frequency function of the synchronization frame. The correlation maximum is detected, and this determines the time slot which contains the synchronization frame, whereupon this is used as time base for the following data frames.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.