Global Patent Index - EP 1618760 A4

EP 1618760 A4 20130320 - RECIPROCAL INDEX LOOKUP FOR BTSC COMPATIBLE COEFFICIENTS

Title (en)

RECIPROCAL INDEX LOOKUP FOR BTSC COMPATIBLE COEFFICIENTS

Title (de)

REZIPROK-INDEX-NACHSCHLAGEN FÜR BTSC-KOMPATIBLE KOEFFIZIENTEN

Title (fr)

TABLE DE CONSULTATION D'INDICE RECIPROQUE POUR COEFFICIENTS COMPATIBLES AVEC BTSC

Publication

EP 1618760 A4 20130320 (EN)

Application

EP 03721588 A 20030409

Priority

US 0310834 W 20030409

Abstract (en)

[origin: CA2525944A1] An algorithm calculates spectral expansion filter coefficients (712) using a value proportional to a reciprocal (720) of a feedback/feedforward signal (a ) and stores the coefficients to a lookup table. The lookup table is indexed b y a pre-selected set of coefficient bits to generate a filter coefficient function. A first portion of the lookup table stores a plurality of discrete values at index points of a line segment corresponding to a filter coefficie nt function approximation, so as to generate an initial discrete value corresponding to the filter coefficient function at a value of the high orde r bits and a second portion stores a plurality of slope values, which indicate s a slope of the filter coefficient function. A linear circuit interpolates/decimates an approximation of the compression/expansion filter coefficient function based on the slope value, the initial discrete value an d a preselected set of low order bits of the reciprocal value.

IPC 8 full level

H03G 7/00 (2006.01); H04N 5/60 (2006.01); H04N 7/12 (2006.01); H04R 5/00 (2006.01)

CPC (source: EP)

H03G 7/007 (2013.01); H04N 5/602 (2013.01)

Citation (search report)

Designated contracting state (EPC)

AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HU IE IT LI LU MC NL PT RO SE SI SK TR

DOCDB simple family (publication)

AU 2003224895 A1 20041126; CA 2525944 A1 20041118; CA 2525944 C 20120605; CN 1795697 A 20060628; EP 1618760 A1 20060125; EP 1618760 A4 20130320

DOCDB simple family (application)

AU 2003224895 A 20030409; CA 2525944 A 20030409; CN 03826605 A 20030409; EP 03721588 A 20030409