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:
Oct. 30, 1990
Filed:
Sep. 14, 1989
Hikmet Sari, Creteil, FR;
U.S. Philips Corporation, New York, NY (US);
Abstract
An adaptive predistortion circuit for a digital transmission system which comprises a predistortion circuit (52.sub.1, 52.sub.2) predistorting the input data prior to their entering a modulator (56) and thereafter an amplifier (57), and an adaptation circuit (61.sub.1, 61.sub.2) continuously adapting the predistortion circuit to the stream of transmitted data in response to a demodulation of the stream of transmitted data. The predistortion circuit further comprises an encoder (51) which, on the basis of digital data a.sub.k, generates on a first path digital data b.sub.k which leave a first predistortion circuit (52.sub.1) in a predistorted manner and in-phase with the symbol clock, and on a second path digital data c.sub.k which leave a second predistortion circuit (52.sub.2) in a predistorted manner and in phase-opposition to the symbol clock. The signals b.sub.k and c.sub.k are obtained by means of a polynomial encoding. The encoding may be effected with the aid of shift registers (62.sub.1 . . . 62.sub.I) addressing a memory.