---
_id: '11862'
abstract:
- lang: eng
  text: In this contribution we extend a previously proposed Bayesian approach for
    the enhancement of reverberant logarithmic mel power spectral coefficients for
    robust automatic speech recognition to the additional compensation of background
    noise. A recently proposed observation model is employed whose time-variant observation
    error statistics are obtained as a side product of the inference of the a posteriori
    probability density function of the clean speech feature vectors. Further a reduction
    of the computational effort and the memory requirements are achieved by using
    a recursive formulation of the observation model. The performance of the proposed
    algorithms is first experimentally studied on a connected digits recognition task
    with artificially created noisy reverberant data. It is shown that the use of
    the time-variant observation error model leads to a significant error rate reduction
    at low signal-to-noise ratios compared to a time-invariant model. Further experiments
    were conducted on a 5000 word task recorded in a reverberant and noisy environment.
    A significant word error rate reduction was obtained demonstrating the effectiveness
    of the approach on real-world data.
author:
- first_name: Volker
  full_name: Leutnant, Volker
  last_name: Leutnant
- first_name: Alexander
  full_name: Krueger, Alexander
  last_name: Krueger
- first_name: Reinhold
  full_name: Haeb-Umbach, Reinhold
  id: '242'
  last_name: Haeb-Umbach
citation:
  ama: Leutnant V, Krueger A, Haeb-Umbach R. Bayesian Feature Enhancement for Reverberation
    and Noise Robust Speech Recognition. <i>IEEE Transactions on Audio, Speech, and
    Language Processing</i>. 2013;21(8):1640-1652. doi:<a href="https://doi.org/10.1109/TASL.2013.2258013">10.1109/TASL.2013.2258013</a>
  apa: Leutnant, V., Krueger, A., &#38; Haeb-Umbach, R. (2013). Bayesian Feature Enhancement
    for Reverberation and Noise Robust Speech Recognition. <i>IEEE Transactions on
    Audio, Speech, and Language Processing</i>, <i>21</i>(8), 1640–1652. <a href="https://doi.org/10.1109/TASL.2013.2258013">https://doi.org/10.1109/TASL.2013.2258013</a>
  bibtex: '@article{Leutnant_Krueger_Haeb-Umbach_2013, title={Bayesian Feature Enhancement
    for Reverberation and Noise Robust Speech Recognition}, volume={21}, DOI={<a href="https://doi.org/10.1109/TASL.2013.2258013">10.1109/TASL.2013.2258013</a>},
    number={8}, journal={IEEE Transactions on Audio, Speech, and Language Processing},
    author={Leutnant, Volker and Krueger, Alexander and Haeb-Umbach, Reinhold}, year={2013},
    pages={1640–1652} }'
  chicago: 'Leutnant, Volker, Alexander Krueger, and Reinhold Haeb-Umbach. “Bayesian
    Feature Enhancement for Reverberation and Noise Robust Speech Recognition.” <i>IEEE
    Transactions on Audio, Speech, and Language Processing</i> 21, no. 8 (2013): 1640–52.
    <a href="https://doi.org/10.1109/TASL.2013.2258013">https://doi.org/10.1109/TASL.2013.2258013</a>.'
  ieee: V. Leutnant, A. Krueger, and R. Haeb-Umbach, “Bayesian Feature Enhancement
    for Reverberation and Noise Robust Speech Recognition,” <i>IEEE Transactions on
    Audio, Speech, and Language Processing</i>, vol. 21, no. 8, pp. 1640–1652, 2013.
  mla: Leutnant, Volker, et al. “Bayesian Feature Enhancement for Reverberation and
    Noise Robust Speech Recognition.” <i>IEEE Transactions on Audio, Speech, and Language
    Processing</i>, vol. 21, no. 8, 2013, pp. 1640–52, doi:<a href="https://doi.org/10.1109/TASL.2013.2258013">10.1109/TASL.2013.2258013</a>.
  short: V. Leutnant, A. Krueger, R. Haeb-Umbach, IEEE Transactions on Audio, Speech,
    and Language Processing 21 (2013) 1640–1652.
date_created: 2019-07-12T05:29:42Z
date_updated: 2022-01-06T06:51:11Z
department:
- _id: '54'
doi: 10.1109/TASL.2013.2258013
intvolume: '        21'
issue: '8'
keyword:
- Bayes methods
- compensation
- error statistics
- reverberation
- speech recognition
- Bayesian feature enhancement
- background noise
- clean speech feature vectors
- compensation
- connected digits recognition task
- error statistics
- memory requirements
- noisy reverberant data
- posteriori probability density function
- recursive formulation
- reverberant logarithmic mel power spectral coefficients
- robust automatic speech recognition
- signal-to-noise ratios
- time-variant observation
- word error rate reduction
- Robust automatic speech recognition
- model-based Bayesian feature enhancement
- observation model for reverberant and noisy speech
- recursive observation model
language:
- iso: eng
page: 1640-1652
publication: IEEE Transactions on Audio, Speech, and Language Processing
status: public
title: Bayesian Feature Enhancement for Reverberation and Noise Robust Speech Recognition
type: journal_article
user_id: '44006'
volume: 21
year: '2013'
...
---
_id: '11785'
abstract:
- lang: eng
  text: 'In this paper we present a novel channel impulse response estimation technique
    for block-oriented OFDM transmission based on combining estimators: the estimates
    provided by a Kalman filter operating in the time domain and a Wiener filter in
    the frequency domain are optimally combined by taking into account their estimated
    error covariances. The resulting estimator turns out to be identical to the MAP
    estimator of correlated jointly Gaussian mean vectors. Different variants of the
    proposed scheme are experimentally investigated in an EEEE 802.11a-like system
    setup. They compare favourably with known approaches from the literature resulting
    in reduced mean square estimation error and bit error rate. Further, robustness
    and complexity issues are discussed'
author:
- first_name: Reinhold
  full_name: Haeb-Umbach, Reinhold
  id: '242'
  last_name: Haeb-Umbach
- first_name: Maik
  full_name: Bevermeier, Maik
  last_name: Bevermeier
citation:
  ama: 'Haeb-Umbach R, Bevermeier M. OFDM Channel Estimation Based on Combined Estimation
    in Time and Frequency Domain. In: <i>IEEE International Conference on Acoustics,
    Speech and Signal Processing (ICASSP 2007)</i>. Vol 3. ; 2007:III-277-III-280.
    doi:<a href="https://doi.org/10.1109/ICASSP.2007.366526">10.1109/ICASSP.2007.366526</a>'
  apa: Haeb-Umbach, R., &#38; Bevermeier, M. (2007). OFDM Channel Estimation Based
    on Combined Estimation in Time and Frequency Domain. In <i>IEEE International
    Conference on Acoustics, Speech and Signal Processing (ICASSP 2007)</i> (Vol.
    3, pp. III-277-III–280). <a href="https://doi.org/10.1109/ICASSP.2007.366526">https://doi.org/10.1109/ICASSP.2007.366526</a>
  bibtex: '@inproceedings{Haeb-Umbach_Bevermeier_2007, title={OFDM Channel Estimation
    Based on Combined Estimation in Time and Frequency Domain}, volume={3}, DOI={<a
    href="https://doi.org/10.1109/ICASSP.2007.366526">10.1109/ICASSP.2007.366526</a>},
    booktitle={IEEE International Conference on Acoustics, Speech and Signal Processing
    (ICASSP 2007)}, author={Haeb-Umbach, Reinhold and Bevermeier, Maik}, year={2007},
    pages={III-277-III–280} }'
  chicago: Haeb-Umbach, Reinhold, and Maik Bevermeier. “OFDM Channel Estimation Based
    on Combined Estimation in Time and Frequency Domain.” In <i>IEEE International
    Conference on Acoustics, Speech and Signal Processing (ICASSP 2007)</i>, 3:III-277-III–280,
    2007. <a href="https://doi.org/10.1109/ICASSP.2007.366526">https://doi.org/10.1109/ICASSP.2007.366526</a>.
  ieee: R. Haeb-Umbach and M. Bevermeier, “OFDM Channel Estimation Based on Combined
    Estimation in Time and Frequency Domain,” in <i>IEEE International Conference
    on Acoustics, Speech and Signal Processing (ICASSP 2007)</i>, 2007, vol. 3, pp.
    III-277-III–280.
  mla: Haeb-Umbach, Reinhold, and Maik Bevermeier. “OFDM Channel Estimation Based
    on Combined Estimation in Time and Frequency Domain.” <i>IEEE International Conference
    on Acoustics, Speech and Signal Processing (ICASSP 2007)</i>, vol. 3, 2007, pp.
    III-277-III–280, doi:<a href="https://doi.org/10.1109/ICASSP.2007.366526">10.1109/ICASSP.2007.366526</a>.
  short: 'R. Haeb-Umbach, M. Bevermeier, in: IEEE International Conference on Acoustics,
    Speech and Signal Processing (ICASSP 2007), 2007, pp. III-277-III–280.'
date_created: 2019-07-12T05:28:13Z
date_updated: 2022-01-06T06:51:08Z
department:
- _id: '54'
doi: 10.1109/ICASSP.2007.366526
intvolume: '         3'
keyword:
- bit error rate
- block-oriented OFDM transmission
- channel estimation
- channel impulse response estimation
- combining estimators
- error statistics
- frequency domain estimation
- Gaussian mean vectors
- Gaussian processes
- Kalman filter
- Kalman filters
- MAP estimator
- maximum likelihood estimation
- OFDM channel estimation
- OFDM modulation
- time domain estimation
- time-frequency analysis
- Wiener filter
- Wiener filters
language:
- iso: eng
main_file_link:
- open_access: '1'
  url: https://groups.uni-paderborn.de/nt/pubs/2007/HaBe07.pdf
oa: '1'
page: III-277-III-280
publication: IEEE International Conference on Acoustics, Speech and Signal Processing
  (ICASSP 2007)
status: public
title: OFDM Channel Estimation Based on Combined Estimation in Time and Frequency
  Domain
type: conference
user_id: '44006'
volume: 3
year: '2007'
...
---
_id: '11870'
abstract:
- lang: eng
  text: We derive a class of computationally inexpensive linear dimension reduction
    criteria by introducing a weighted variant of the well-known K-class Fisher criterion
    associated with linear discriminant analysis (LDA). It can be seen that LDA weights
    contributions of individual class pairs according to the Euclidean distance of
    the respective class means. We generalize upon LDA by introducing a different
    weighting function
author:
- first_name: M.
  full_name: Loog, M.
  last_name: Loog
- first_name: R.P.W.
  full_name: Duin, R.P.W.
  last_name: Duin
- first_name: Reinhold
  full_name: Haeb-Umbach, Reinhold
  id: '242'
  last_name: Haeb-Umbach
citation:
  ama: Loog M, Duin RPW, Haeb-Umbach R. Multiclass linear dimension reduction by weighted
    pairwise Fisher criteria. <i>IEEE Transactions on Pattern Analysis and Machine
    Intelligence</i>. 2001;23(7):762-766. doi:<a href="https://doi.org/10.1109/34.935849">10.1109/34.935849</a>
  apa: Loog, M., Duin, R. P. W., &#38; Haeb-Umbach, R. (2001). Multiclass linear dimension
    reduction by weighted pairwise Fisher criteria. <i>IEEE Transactions on Pattern
    Analysis and Machine Intelligence</i>, <i>23</i>(7), 762–766. <a href="https://doi.org/10.1109/34.935849">https://doi.org/10.1109/34.935849</a>
  bibtex: '@article{Loog_Duin_Haeb-Umbach_2001, title={Multiclass linear dimension
    reduction by weighted pairwise Fisher criteria}, volume={23}, DOI={<a href="https://doi.org/10.1109/34.935849">10.1109/34.935849</a>},
    number={7}, journal={IEEE Transactions on Pattern Analysis and Machine Intelligence},
    author={Loog, M. and Duin, R.P.W. and Haeb-Umbach, Reinhold}, year={2001}, pages={762–766}
    }'
  chicago: 'Loog, M., R.P.W. Duin, and Reinhold Haeb-Umbach. “Multiclass Linear Dimension
    Reduction by Weighted Pairwise Fisher Criteria.” <i>IEEE Transactions on Pattern
    Analysis and Machine Intelligence</i> 23, no. 7 (2001): 762–66. <a href="https://doi.org/10.1109/34.935849">https://doi.org/10.1109/34.935849</a>.'
  ieee: M. Loog, R. P. W. Duin, and R. Haeb-Umbach, “Multiclass linear dimension reduction
    by weighted pairwise Fisher criteria,” <i>IEEE Transactions on Pattern Analysis
    and Machine Intelligence</i>, vol. 23, no. 7, pp. 762–766, 2001.
  mla: Loog, M., et al. “Multiclass Linear Dimension Reduction by Weighted Pairwise
    Fisher Criteria.” <i>IEEE Transactions on Pattern Analysis and Machine Intelligence</i>,
    vol. 23, no. 7, 2001, pp. 762–66, doi:<a href="https://doi.org/10.1109/34.935849">10.1109/34.935849</a>.
  short: M. Loog, R.P.W. Duin, R. Haeb-Umbach, IEEE Transactions on Pattern Analysis
    and Machine Intelligence 23 (2001) 762–766.
date_created: 2019-07-12T05:29:51Z
date_updated: 2022-01-06T06:51:11Z
department:
- _id: '54'
doi: 10.1109/34.935849
intvolume: '        23'
issue: '7'
keyword:
- approximate pairwise accuracy
- Bayes error
- Bayes methods
- error statistics
- Euclidean distance
- Fisher criterion
- linear dimension reduction
- linear discriminant analysis
- pattern classification
- statistical analysis
- statistical pattern classification
- weighting function
language:
- iso: eng
main_file_link:
- open_access: '1'
  url: https://groups.uni-paderborn.de/nt/pubs/2001/LoDuHa01.pdf
oa: '1'
page: 762-766
publication: IEEE Transactions on Pattern Analysis and Machine Intelligence
status: public
title: Multiclass linear dimension reduction by weighted pairwise Fisher criteria
type: journal_article
user_id: '44006'
volume: 23
year: '2001'
...
