The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
May. 11, 2004
Filed:
Jun. 14, 2000
Fujitsu Limited, Kawasaki, JP;
Abstract
A data transmission system which trains its internal equalizers both in an initialization phase and in a normal communication session. In a transmitter unit, a modulation unit modulates a data signal to be transmitted. This signal is sent out to a telephone subscriber line by a transmitter after being added a cyclic prefix by a prefixing unit. A receiver unit accepts the data signal at its receiver portion. The received signal, however, has been impaired because of non-ideal transmission characteristics of the subscriber line. The receiver unit employs a processor which serves as an equalizer to confine the signal impairment within a period of cyclic prefix of each symbol. The receiver unit further comprises a target channel which provides reference characteristics for use in adapting the processor to the current line characteristics. At an initialization stage, a first training unit performs training by tuning both the target channel and processor. When a normal communication session begins, a second training unit performs training by mainly tuning the processor.