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:
Sep. 20, 2005
Filed:
Nov. 30, 1999
Douglas Wong, San Diego, CA (US);
Douglas Wong, San Diego, CA (US);
Verance Corporation, San Diego, CA (US);
Abstract
An oversampled filter bank structure that can be implemented using popular and efficient fast filter banks to allow subband processing of an input signal with substantially reduced aliasing between subbands. Even subbands (SB, SB, SB, . . . ) of an input signal (x(n)) are frequency-shifted () prior to analysis filtering () at a 2× oversampled filter bank, subband processing (), and synthesis filtering (). A subsequent frequency-shift () returns the even subbands to their original band positions. The odd subbands (SB, SB, SB, . . . ) are delayed () to compensate for the processing time of the frequency shifting. Separate analysis (') and synthesis (′) filter banks may be provided for the even and odd subbands, or common complex analysis () and synthesis () filter banks may be used. In another embodiment, the subbands are processed in four subband paths (Paths), and× oversampling is used. A filter bank structure () for 2-D data is also provided.