Method and device for synchronization at OFDM-system
US5812523A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 30, 1995 |
| Grant date | Sep 22, 1998 |
| Priority date | — |
| Expiry date | Mar 30, 2015 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L27/2662
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
A method of demultiplexing OFDM signals and a receiver for such signals. More particularly the method is concerned with synchronization in an OFDM receiver. A signal is read into a synchronization unit, in the time domain, i.e., before fourier transforming the signal by means of an FFT processor. In the synchronization unit, a frame clock is derived for triggering the start of the FFT process and for controlling the rate at which data is supplied to the FFT processor. For OFDM reception, it is vital that the FFT process commences at the right point in time. Once the frame clock has been recovered, a frequency error can be estimated by the synchronization unit. The frequency error is used to control; an oscillator which generates a complex rotating vector which is, in turn, multiplied with the signal to compensate for frequency errors. The method can be used both with OFDM systems in which symbols are separated by guard spaces, and with OFDM systems in which symbols are pulse shaped.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.