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US006252908B1
(12) United States Patent ao) Patent No.: us 6,252,908 Bi
Tore (45) Date of Patent: *Jun. 26,2001
(54) METHOD AND DEVICE IN A COMMUNICATION SYSTEM
(75) Inventor: Andre Tore, Alvsjo (SE)
(73) Assignee: Telefonaktiebolaget LM Ericsson (publ), Stockholm (SE)
( * ) Notice: This patent issued on a continued prosecution application filed under 37 CFR 1.53(d), and is subject to the twenty year patent term provisions of 35 U.S.C. 154(a)(2).
Subject to any disclaimer, the term of this patent is extended or adjusted under 35 U.S.C. 154(b) by 0 days.
(21) Appl. No.: 09/355,483
(22) PCT Filed: Jan. 30, 1998
(86) PCT No.: PCT/SE98/00138 § 371 Date: Nov. 17, 1999
§ 102(e) Date: Nov. 17, 1999
(87) PCT Pub. No.: W098/34368 PCT Pub. Date: Aug. 6, 1998
(30) Foreign Application Priority Data Jan. 31, 1997 (SE) 9700308
(51) Int. C I. H04L 27/00
(52) U.S. CI 375/259; 375/355
(58) Field of Search 375/260, 355,
375/259, 362, 364, 368, 369, 371, 373,
376
The present invention concerns a method and a device for the synchronization of a transmitter (1) and at least one receiver (3) in multi-carrier modulated communication systems in which FFT technology is used for the modulation and demodulation of data transmitted between the transmitter (1) and the receiver (3). According to the invention the transmitter (1) transmits synchronization symbols (15, 16) as training symbols (15, 16) at the beginning of a transmission, until a result is obtained that may indicate where a synchronization symbol starts. The result is used for the adjustment of the symbol rate in the receiver (3). Data symbols may then be transmitted after the synchronization symbols (15, 16).
14 Claims, 5 Drawing Sheets
