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:
Apr. 13, 1999
Filed:
Jun. 10, 1997
Rainer Kase, Dusseldorf, DE;
Toshiba Electronics Europe GmbH, Dusseldorf, DE;
Abstract
This invention relates to adaptive digital filters for echo cancellation in a bi-directional data transmission channel. Substantial hardware savings for a digital adaptive filter are possible, if hardware structures for performing filter operations are shared. In a digital adaptive filter with resource sharing filter operations are performed sequentially with a limited number of hardware structures. This invention discloses a digital adaptive filter with resource sharing with further hardware savings (FIG. 3). Corresponding to a characteristic decrease of the magnitude of the filter coefficients for echo cancellation, a first and second filter computation means (4.sub.A, 4.sub.B) are connected to a coefficient storage means (3) with a different bit width to receive coefficients (c.sub.0, c.sub.1 . . . c.sub.N/2-2, c.sub.N/2-1 ; c.sub.N/2, c.sub.N/2+1 . . . c.sub.N-2, c.sub.N-1) having different magnitudes and/or a first and second coefficient adapting means (7.sub.A, 7.sub.B) are connected to the coefficient storage means (3) with a different bit width to receive coefficients (c.sub.0, c.sub.1 . . . c.sub.N/2-2, c.sub.N/2-1 ; c.sub.N/2, c.sub.N/2+1 . . . c.sub.N-2, c.sub.N-1) having different magnitudes, allowing a hardware reduction the and reduction of the size of the filter device.