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. 08, 2006
Filed:
Oct. 02, 2003
Mohammad Jaber Borran, Irving, TX (US);
Behnaam Aazhang, Houston, TX (US);
Mohammad Jaber Borran, Irving, TX (US);
Behnaam Aazhang, Houston, TX (US);
Nokia Corporation, Espoo, FI;
Abstract
A signal constellation is optimized for trellis coded modulation in fast fading channels, where the receiver does not have perfect knowledge of the channel parameters. Specifically, the signal constellation is partitioned into 2mutually exclusive subsets, each preferably defining two points. Points within each subset are separated from one another by a distance between conditional distributions, preferably a Kullback-Leibler (KL) distance. For a block m=k+kof information bits input into a trellis coder, the kbits are trellis encoded into n bits (n>k) and used to select a subset of the constellation. The kbit(s) is/are used to select a particular point within the subset. Because the inter-subset distance between points is a KL distance that is effectively greater than a Euclidean distance, error at the receiver is substantially reduced, especially at higher SNR. Using a KL distance ensures statistics of channel fading are inherent within the signal constellation.