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:
Aug. 30, 1994
Filed:
Jul. 09, 1992
William L Betts, St. Petersburg, FL (US);
Arthur R Calderbank, Maplewood, NJ (US);
Burton R Saltzberg, Middletown, NJ (US);
AT&T Bell Laboratories, Murray Hill, NJ (US);
Abstract
In order to mitigate against the multiplicative noise effects caused by known non-linearities in a trellis coded data transmission system, a signal constellation is formed by starting with a base constellation whose number of signal points and whose geometry are selected in accordance with conventional criteria and then warping that constellation by adjusting the positions of its signal points in accordance with a warp function which is the inverse of the known component of the non-linear characteristic of the transmission system. Because the constellation warping is deterministic, it is possible for the receiver to 'unwarp' the received signal points prior to applying them to the Viterbi decoder. In preferred embodiments, the trellis code is of a type in which the dominant error event is a trellis path error.