Method and apparatus for estimating a frequency offset

US6104767A · kind A · utility

Assignee

• Telefonaktiebolaget LM Ericsson (Publ) · SE

Inventors

• Roozbeh Atarius · San Diego, US
• Georg Frank · Nürnberg, DE

Key dates

• Filing date: Nov 17, 1997
• Grant date: Aug 15, 2000
• Expiry date: Nov 17, 2017

Classification

• Technology area (CPC H): Electricity
• CPC primary: H04L2027/0065
• WIPO field: Digital communication
• WIPO sector: Electrical engineering

Abstract

In a communication system including at least one transmitter and at least one receiver, a frequency offset between a carrier frequency of the transmitter and a local frequency reference of the receiver is estimated. A phase difference is computed between successively collected samples of a frequency synchronization signal transmitted by the transmitter and detected by the receiver. The phase difference is added to accumulated phase differences. Phase differences of successively collected samples are computed and added to accumulated phase differences until M accumulated phase differences have been added. The sum of the M phase differences is dumped, resulting in zero accumulated phase differences. Phase differences of successively collected samples are computed, the phase differences are added to accumulated phase differences, and the sum of M phase differences is dumped until N sums of M phase differences have been dumped. The N sums of the M phase differences are added to produce the estimated frequency offset.