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US 6,487,527 B1Granted
Enhanced quantization method for spectral frequency coding
AssigneeSeda Solutions Corp.
InventorRahmin Soheili
Life of this patent
Estimating the term…
Abstract
A linear predictive speech encoding method combines vector quantization with the search for roots of LSP polynomials. At Under this method, a code book searchable using line spectral pair (LSP) values is created from a line spectral frequency (LSF) code book, thus ensuring linear distortion performance without the costly run-time complexity of finding roots to high-order LSP polynomials in the LSF domain.
Claims6
A method for speech encoding, comprising:
- creating, from a table of quantized line spectral frequency values, an indexed table having as entries quantized line spectral pair (LSP) values;
- and
- during each update period, (a) extracting from a frame of speech signal a set of LPC coefficients;
- (b) deriving from said set of LPC coefficients LSP polynomials P(x) and Q(x), (c) evaluating said polynomials P(x) and Q(x) using said quantized LSP values, and (d) selecting from said quantized LSP values approximate roots of said polynomials ERE P(x) and Q(x);
- and
- representing said approximate roots by the index of the entry of said table corresponding to said approximate roots.
3 more elements
Dependencies are inferred from the claim text.