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:
May. 21, 2002
Filed:
Dec. 06, 1999
Jayesh S. Patel, Lowell, MA (US);
Douglas E. Kolb, Bedford, MA (US);
Other;
Abstract
A method and apparatus for reducing the complexity of linear prediction analysis-by-synthesis (LPAS) speech coders. The method and apparatus include product code vector quantization (PCVQ) of multi-tap pitch predictor coefficients, which reduces the search and quantization complexity of an adaptive codebook. The pitch predictor vector quantizes the predictor parameters using at least two codebooks, which are effectively subcodebooks of the pitch predictor adaptive codebook. Further included is a procedure for generating and selecting code vectors consisting of ternary (1,0,−1) values, for optimizing a fixed codebook. The fixed codebook makes a single pass derivation of pulse position in the excitation signal. Serial optimization of the adaptive codebook first and then the fixed codebook, produces a low complexity LPAS speech coder of the present invention.