Different approximate cepstra using subband-transforms

Theory and applications

Abdulnasir Hossen, Ulrich Heute

Research output: Contribution to journalArticle

1 Citation (Scopus)

Abstract

Cepstrum analysis is a nonlinear signal-processing method with a variety of applications in areas such as speech, image, and seismic signal processing. The idea of the subband- transforms (the subband-DFT (SB-DFT) and the subband-DCT (SB-DCT)) is to decompose the input signal into low- and high- frequency bands, and then to process the two bands separately after down-sampling. Approximation can be done if it is known that the energy is concentrated in one of the bands. So only this band is calculated resulting in an approximate transform with less computational complexity. In this work the idea of both subband transforms is reviewed. Both transforms are used in cepstrum computation. The SB-DFT cepstrum and the SB-DCT cepstrum are compared in terms of their computational complexity and efficiency with respect to the full- band DFT and full-band DCT cepstra. In many speech processing applications, the DFT-based cepstrum is used to determine the mode of excitation of the model (voiced or unvoiced) and, for voiced speech, the pitch period. In this work the approximated subband-DFT (SB-DFT) is used instead of the full-band DFT (or FFT) to determine both the real cepstrum (called also simply the cepstrum) and the complex cepstrum. It is shown that using the approximate SB-DFT in speech applications does not degrade the information contained in the cepstrum while the computational complexity is highly reduced. The approximated complex cepstrum is used in the problem of echo detection. The adaptive capability of the SB-DFT is included in both SB-DFT cepstrum and SB-DCT cepstrum to adaptively detect the echo for different input frequency bands. Complexity and efficiency of echo detection algorithms based on SB-DFT and SB- DCT cepstra are compared.

Original languageEnglish
Pages (from-to)247-254
Number of pages8
JournalAEU - International Journal of Electronics and Communications
Volume57
Issue number4
DOIs
Publication statusPublished - 2003

Fingerprint

Discrete Fourier transforms
Mathematical transformations
Computational complexity
Frequency bands
Signal processing
Speech processing
Computational efficiency
Fast Fourier transforms
Sampling

Keywords

  • Cepstrum analysis
  • Nonlinear signal processing
  • Sub-band transforms

ASJC Scopus subject areas

  • Electrical and Electronic Engineering

Cite this

Different approximate cepstra using subband-transforms : Theory and applications. / Hossen, Abdulnasir; Heute, Ulrich.

In: AEU - International Journal of Electronics and Communications, Vol. 57, No. 4, 2003, p. 247-254.

Research output: Contribution to journalArticle

@article{ecd82ae9010d4942a4cdead8ccf48df9,
title = "Different approximate cepstra using subband-transforms: Theory and applications",
abstract = "Cepstrum analysis is a nonlinear signal-processing method with a variety of applications in areas such as speech, image, and seismic signal processing. The idea of the subband- transforms (the subband-DFT (SB-DFT) and the subband-DCT (SB-DCT)) is to decompose the input signal into low- and high- frequency bands, and then to process the two bands separately after down-sampling. Approximation can be done if it is known that the energy is concentrated in one of the bands. So only this band is calculated resulting in an approximate transform with less computational complexity. In this work the idea of both subband transforms is reviewed. Both transforms are used in cepstrum computation. The SB-DFT cepstrum and the SB-DCT cepstrum are compared in terms of their computational complexity and efficiency with respect to the full- band DFT and full-band DCT cepstra. In many speech processing applications, the DFT-based cepstrum is used to determine the mode of excitation of the model (voiced or unvoiced) and, for voiced speech, the pitch period. In this work the approximated subband-DFT (SB-DFT) is used instead of the full-band DFT (or FFT) to determine both the real cepstrum (called also simply the cepstrum) and the complex cepstrum. It is shown that using the approximate SB-DFT in speech applications does not degrade the information contained in the cepstrum while the computational complexity is highly reduced. The approximated complex cepstrum is used in the problem of echo detection. The adaptive capability of the SB-DFT is included in both SB-DFT cepstrum and SB-DCT cepstrum to adaptively detect the echo for different input frequency bands. Complexity and efficiency of echo detection algorithms based on SB-DFT and SB- DCT cepstra are compared.",
keywords = "Cepstrum analysis, Nonlinear signal processing, Sub-band transforms",
author = "Abdulnasir Hossen and Ulrich Heute",
year = "2003",
doi = "10.1078/1434-8411-54100167",
language = "English",
volume = "57",
pages = "247--254",
journal = "AEU - International Journal of Electronics and Communications",
issn = "1434-8411",
publisher = "Urban und Fischer Verlag Jena",
number = "4",

}

TY - JOUR

T1 - Different approximate cepstra using subband-transforms

T2 - Theory and applications

AU - Hossen, Abdulnasir

AU - Heute, Ulrich

PY - 2003

Y1 - 2003

N2 - Cepstrum analysis is a nonlinear signal-processing method with a variety of applications in areas such as speech, image, and seismic signal processing. The idea of the subband- transforms (the subband-DFT (SB-DFT) and the subband-DCT (SB-DCT)) is to decompose the input signal into low- and high- frequency bands, and then to process the two bands separately after down-sampling. Approximation can be done if it is known that the energy is concentrated in one of the bands. So only this band is calculated resulting in an approximate transform with less computational complexity. In this work the idea of both subband transforms is reviewed. Both transforms are used in cepstrum computation. The SB-DFT cepstrum and the SB-DCT cepstrum are compared in terms of their computational complexity and efficiency with respect to the full- band DFT and full-band DCT cepstra. In many speech processing applications, the DFT-based cepstrum is used to determine the mode of excitation of the model (voiced or unvoiced) and, for voiced speech, the pitch period. In this work the approximated subband-DFT (SB-DFT) is used instead of the full-band DFT (or FFT) to determine both the real cepstrum (called also simply the cepstrum) and the complex cepstrum. It is shown that using the approximate SB-DFT in speech applications does not degrade the information contained in the cepstrum while the computational complexity is highly reduced. The approximated complex cepstrum is used in the problem of echo detection. The adaptive capability of the SB-DFT is included in both SB-DFT cepstrum and SB-DCT cepstrum to adaptively detect the echo for different input frequency bands. Complexity and efficiency of echo detection algorithms based on SB-DFT and SB- DCT cepstra are compared.

AB - Cepstrum analysis is a nonlinear signal-processing method with a variety of applications in areas such as speech, image, and seismic signal processing. The idea of the subband- transforms (the subband-DFT (SB-DFT) and the subband-DCT (SB-DCT)) is to decompose the input signal into low- and high- frequency bands, and then to process the two bands separately after down-sampling. Approximation can be done if it is known that the energy is concentrated in one of the bands. So only this band is calculated resulting in an approximate transform with less computational complexity. In this work the idea of both subband transforms is reviewed. Both transforms are used in cepstrum computation. The SB-DFT cepstrum and the SB-DCT cepstrum are compared in terms of their computational complexity and efficiency with respect to the full- band DFT and full-band DCT cepstra. In many speech processing applications, the DFT-based cepstrum is used to determine the mode of excitation of the model (voiced or unvoiced) and, for voiced speech, the pitch period. In this work the approximated subband-DFT (SB-DFT) is used instead of the full-band DFT (or FFT) to determine both the real cepstrum (called also simply the cepstrum) and the complex cepstrum. It is shown that using the approximate SB-DFT in speech applications does not degrade the information contained in the cepstrum while the computational complexity is highly reduced. The approximated complex cepstrum is used in the problem of echo detection. The adaptive capability of the SB-DFT is included in both SB-DFT cepstrum and SB-DCT cepstrum to adaptively detect the echo for different input frequency bands. Complexity and efficiency of echo detection algorithms based on SB-DFT and SB- DCT cepstra are compared.

KW - Cepstrum analysis

KW - Nonlinear signal processing

KW - Sub-band transforms

UR - http://www.scopus.com/inward/record.url?scp=84878933592&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=84878933592&partnerID=8YFLogxK

U2 - 10.1078/1434-8411-54100167

DO - 10.1078/1434-8411-54100167

M3 - Article

VL - 57

SP - 247

EP - 254

JO - AEU - International Journal of Electronics and Communications

JF - AEU - International Journal of Electronics and Communications

SN - 1434-8411

IS - 4

ER -