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. 06, 2005
Filed:
Jun. 29, 2001
Hong Wang, Bellevue, WA (US);
Vladimir Cuperman, Goleta, CA (US);
Allen Gersho, Santa Barbara, CA (US);
Hosam A. Khalil, Bellevue, WA (US);
Hong Wang, Bellevue, WA (US);
Vladimir Cuperman, Goleta, CA (US);
Allen Gersho, Santa Barbara, CA (US);
Hosam A. Khalil, Bellevue, WA (US);
Microsoft Corporation, Redmond, VA (US);
Abstract
A method and system of performing postfiltering in the frequency domain to improve the quality of a speech signal, especially for synthesized speech resulting from codecs of low bit-rate, is provided. The method comprises LPC tilt computation and compensation methods and modules, a formant filter gain computation method and module, and an anti-aliasing method and module. The formant filter gain calculation employs an LPC representation, an all-pole modeling, a non-linear transformation and a phase computation. The LPC used for deriving the postfilter may be transmitted from an encoder or may be estimated from a synthesized or other speech signal in a decoder or receiver. The invention may be implemented in a linked decoder and encoder. A separate LPC evaluation unit that is responsible for processing and or deriving the LPC may be implemented within the invention.