Coarse frequency synchronization in multicarrier systems

US6993094B1 · kind B1 · utility

Assignee

• Fraunhofer-Gesellschaft zur förderung der angewandten Forschung e.V. · DE

Inventors

• Ernst Eberlein · Erlangen, DE
• Sabah Badri · Erlangen, DE
• Stefan Lipp · Bad Liebenzell, DE
• Stephan Buchholz · Munich, DE
• Albert Heuberger · Erlangen, DE
• Heinz Gerhaeuser · Erlangen, DE

Key dates

• Filing date: Apr 14, 1998
• Grant date: Jan 31, 2006
• Expiry date: Apr 14, 2018

Classification

• Technology area (CPC H): Electricity
• CPC primary: H04L2027/003
• WIPO field: Digital communication
• WIPO sector: Electrical engineering

Abstract

A method and apparatus provide coarse frequency synchronization compensating for a carrier frequency deviation from an oscillator frequency in a demodulation system capable of demodulating a signal having a frame structure with at least one useful symbol and a reference symbol which is an amplitude-modulated sequence. A received and down-converted signal undergoes amplitude-demodulation to generate an envelope that is correlated with a predetermined reference pattern to determine the carrier frequency deviation. Finally, the oscillator frequency is controlled based on the carrier frequency deviation. The reference symbol may comprise two identical sequences. In this case, the envelope obtained by the amplitude-demodulation has two portions which are based on the identical sequences. One of the portions of the envelope is correlated with the other one of the portions in order to determine the carrier frequency deviation. The oscillator frequency is controlled based on the determined carrier frequency deviation.