Jayesh C Patel

US Patent:

6393390, May 21, 2002

Filed:

Dec 6, 1999

Appl. No.:

09/455063

Inventors:

Jayesh S. Patel - Lowell MA 01851
Douglas E. Kolb - Bedford MA 01730

International Classification:

G10L 1904

US Classification:

704207, 704219, 704220, 704222, 704223

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.

US Patent:

6865530, Mar 8, 2005

Filed:

Nov 21, 2001

Appl. No.:

09/991763

Inventors:

Jayesh S. Patel - Lowell MA, US
Douglas E. Kolb - Bedford MA, US

International Classification:

G10L019/10
G10L019/12

US Classification:

704223, 704220, 704222

Abstract:

A method and apparatus for reducing the complexity of linear prediction analysis-by-synthesis (LPAS) speech coders. The speech coder includes a multi-tap pitch predictor having various parameters and utilizing an adaptive codebook subdivided into at least a first vector codebook and a second vector codebook. The pitch predictor removes certain redundancies in a subject speech signal and vector quantizes the pitch predictor parameters. Further included is a source excitation (fixed) codebook that indicates pulses in the subject speech signal by deriving corresponding vector values. Serial optimization of the adaptive codebook first and then the fixed codebook produces a low complexity LPAS speech coder of the present invention.

US Patent:

7200553, Apr 3, 2007

Filed:

Jan 24, 2005

Appl. No.:

11/041478

Inventors:

Jayesh S. Patel - Lowell MA, US
Douglas E. Kolb - Bedford MA, US

Assignee:

Tellabs Operations, Inc. - Naperville IL

International Classification:

G10L 19/08

US Classification:

704223

Abstract:

A method and apparatus for reducing the complexity of linear prediction analysis-by-synthesis (LPAS) speech coders. The speech coder includes a multi-tap pitch predictor having various parameters and utilizing an adaptive codebook subdivided into at least a first vector codebook and a second vector codebook. The pitch predictor removes certain redundancies in a subject speech signal and vector quantizes the pitch predictor parameters. Further included is a source excitation (fixed) codebook that indicates pulses in the subject speech signal by deriving corresponding vector values. Serial optimization of the adaptive codebook first and then the fixed codebook produces a low complexity LPAS speech coder of the present invention.

US Patent:

7359855, Apr 15, 2008

Filed:

Jan 12, 2007

Appl. No.:

11/652732

Inventors:

Jayesh S. Patel - Lowell MA, US
Douglas E. Kolb - Bedford MA, US

Assignee:

Tellabs Operations, Inc. - Naperville IL

International Classification:

G10L 19/10

US Classification:

704223, 704220, 704222

Abstract:

A method and apparatus for reducing the complexity of linear prediction analysis-by synthesis (LPAS) speech coders. The speech coder includes a multi-tap pitch predictor having various parameters and utilizing an adaptive codebook subdivided into at least a first vector codebook and a second vector codebook. The pitch predictor removes certain redundancies in a subject speech signal and vector quantizes the pitch predictor parameters.

US Patent:

60146184, Jan 11, 2000

Filed:

Aug 6, 1998

Appl. No.:

9/130688

Inventors:

Jayesh S. Patel - Lowell MA
Douglas E. Kolb - Bedford MA

Assignee:

DSP Software Engineering, Inc. - Bedford MA

International Classification:

G10L 900

US Classification:

704207

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. Further included is a procedure for generating and selecting code vectors consisting of ternary (1,0,-1) values, for optimizing a fixed codebook. Serial optimization of the adaptive codebook first and then the fixed codebook, produces a low complexity LPAS speech coder of the present invention.