In mobile speech communication, adverse conditions, such as noisy acoustic environments and unreliable network connections, may severely degrade the intelligibility and natural- ness of the receive ...

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Model Based Speech Enhancement and Coding

We introduce multivariate block polar quantization (MBPQ). MBPQ minimizes the weighted squared-error distortion for a set of complex variables representing one block of a signal under a resolution constraint for the entire block. MBPQ performs below the lower bound for classical bivariate quantization, both for Gaussian complex variables and for complex variables found from sinusoidal analysis of audio data. Still, it is of similar complexity as traditional polar quantizers. In the case of audio data, we found a performance gain of about 2.5 dB over the best performing conventional resolution-constrained polar quantization (an extension of unrestricted polar quantization).

Multivariate block polar quantization

Codes. New York: Elsevier North-Holland, 1977. posed on the N-sequence, making the sequence u(k) wide-sense 121 R. J. Lechner, “Harmonic analysis of switching functions,” in Recent stationary with covariance relationships given in (2).’ Moreover, Developments in Switching Theoy, A. Mukhopadhyay, Ed. New York: in the limit of large N, with or without the random shift, as Academic, 1971, pp. 122-230. [31 M. A. Harrison, “Counting theorems and their applications to classificastated in the paper the eigenvalue distributions of K(p) and tion of switching functions,” in Recent Dmelopments in Switching Theory, R,(p) approach each other. That is all that is required for A. Mukhopadhyay, Ed. New York: Academic, 1971, pp. 86-122. deriving coding bounds. h,(p) is the appropriate circulant approximation to the Toeplitz form R,(p). Physically speaking, the edge effects become insignificant for large enough blocks. These large blocks are entirely consistent with the aim of encoding optimally large amounts of data in a DFT. Optimal source coding, as addressed in this paper, requires large N.

A. Meiri

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