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:
Jun. 13, 1989
Filed:
Sep. 20, 1988
Heinz Gockler, Backnang, DE;
ANT Nachrichtentechnik GmbH, Backnang, DE;
Abstract
The invention relates to a digital filter tree composed of a plurality of digital filter banks arranged in a tree structure one behind the other to branch out in stages with a separation into L.sub..nu. individual signals taking place in each stage and the sampling rate being reduced each time by the factor M.sub..nu. where .nu.=1,2, . . . identifies the .nu.th stage. The filter tree employs a prototype filter with half-band functions for channel center frequencies f.sub.l =l.multidot.B+B/2, with a real frequency multiplex input signal being separated into L.sub..nu. complex channel signals for further processing by means of a discrete Fourier transformation. For all stages M.sub..nu. =2 and L.sub..nu. =4 are fixed, with only two signals of the L.sub..nu. =4 being utilized. The arrangement permits adaptation of a hierarchical multi-stage method also to numbers of channels which are not equal to a power of two without changing the input sampling frequency and without the causing channels, whose number is fixed by the difference from the next higher power of two, to idle.