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:
Jan. 24, 1995
Filed:
Sep. 23, 1991
Oscar E Agazzi, Florham Park, NJ (US);
AT&T Bell Laboratories, Murray Hill, NJ (US);
Abstract
An ISDN modem. The modem includes an independent clock which controls the modem's input and output filters and two dependent clocks whose rates are functions of the independent clock and which are synchronized with external timing signals. When a dependent clock is synchronized, timing adjustment signals to other components of the modem specify the type and direction of synchronization. One of the dependent clocks and the independent clock are used to control a decimator which provides two samples of a symbol which are one independent clock cycle apart. One of the samples is a primary sample from which the symbol is interpreted and the other is a secondary sample which is used to continually train a jitter canceller. When a clock is synchronized, the secondary sample becomes the primary sample, providing the modem with a time-invariant echo path. On clock synchronization, the jitter canceller responds to the timing adjustment signals by providing adaptation information to the linear echo canceller.