FIXED CODEBOOK SEARCHING APPARATUS AND FIXED CODEBOOK SEARCHING METHOD

• US 20110202336A1
• Filed: 04/25/2011
• Published: 08/18/2011
• Est. Priority Date: 03/10/2006
• Status: Active Grant

• Current Assignee: III Holdings 12, LLC (Intellectual Ventures LLC)
• Original Assignee: Panasonic Corporation (Panasonic Holdings Corporation)
• Inventors: YOSHIDA, Koji, EHARA, Hiroyuki
• Granted Patent: US 8,452,590 B2
• Time in Patent Office: Days
• US Class Current: 704/219
• CPC Class Codes: G10L 19/107 Sparse pulse excitation, e.g. by using algebraic codebook

Abstract

A fixed codebook searching apparatus, includes a convolution operator, implemented by at least one processor, that convolves an impulse response of a perceptually weighted synthesis filter with an impulse response vector that has values at negative times, to generate a second impulse response vector that has values at negative times. A matrix generator, implemented by at least one processor, generates a Toeplitz-type convolution matrix using the second impulse response vector generated by the convolution operator. A searcher, implemented by at least one processor, performs a codebook search by maximizing a term using the Toeplitz-type convolution matrix.

Claims

1. A fixed codebook searching apparatus, comprising:

a convolution operator, implemented by at least one processor, that convolves an impulse response of a perceptually weighted synthesis filter with an impulse response vector that has values at negative times, to generate a second impulse response vector that has values at negative times;

a matrix generator, implemented by at least one processor, that generates a Toeplitz-type convolution matrix using the second impulse response vector generated by the convolution operator; and

a searcher, implemented by at least one processor, that performs a codebook search by maximizing a term using the Toeplitz-type convolution matrix,

wherein energy of components of the second impulse response vector at negative times is smaller than the energy of components at non-negative times.

2. A fixed codebook searching method, comprising:

convoluting an impulse response of a perceptually weighted synthesis filter with an impulse response vector that has values at negative times, to generate a second impulse response vector that has values at negative times;

generating a Toeplitz-type convolution matrix using the second impulse response vector; and

performing a codebook search by maximizing a term using the Toeplitz-type convolution matrix,

wherein energy of components of the second impulse response vector at negative times is smaller than the energy of components at non-negative times.