---
_id: '11716'
abstract:
- lang: eng
  text: The accuracy of automatic speech recognition systems in noisy and reverberant
    environments can be improved notably by exploiting the uncertainty of the estimated
    speech features using so-called uncertainty-of-observation techniques. In this
    paper, we introduce a new Bayesian decision rule that can serve as a mathematical
    framework from which both known and new uncertainty-of-observation techniques
    can be either derived or approximated. The new decision rule in its direct form
    leads to the new significance decoding approach for Gaussian mixture models, which
    results in better performance compared to standard uncertainty-of-observation
    techniques in different additive and convolutive noise scenarios.
author:
- first_name: Ahmed H.
  full_name: Abdelaziz, Ahmed H.
  last_name: Abdelaziz
- first_name: Steffen
  full_name: Zeiler, Steffen
  last_name: Zeiler
- first_name: Dorothea
  full_name: Kolossa, Dorothea
  last_name: Kolossa
- first_name: Volker
  full_name: Leutnant, Volker
  last_name: Leutnant
- first_name: Reinhold
  full_name: Haeb-Umbach, Reinhold
  id: '242'
  last_name: Haeb-Umbach
citation:
  ama: 'Abdelaziz AH, Zeiler S, Kolossa D, Leutnant V, Haeb-Umbach R. GMM-based significance
    decoding. In: <i>Acoustics, Speech and Signal Processing (ICASSP), 2013 IEEE International
    Conference On</i>. ; 2013:6827-6831. doi:<a href="https://doi.org/10.1109/ICASSP.2013.6638984">10.1109/ICASSP.2013.6638984</a>'
  apa: Abdelaziz, A. H., Zeiler, S., Kolossa, D., Leutnant, V., &#38; Haeb-Umbach,
    R. (2013). GMM-based significance decoding. In <i>Acoustics, Speech and Signal
    Processing (ICASSP), 2013 IEEE International Conference on</i> (pp. 6827–6831).
    <a href="https://doi.org/10.1109/ICASSP.2013.6638984">https://doi.org/10.1109/ICASSP.2013.6638984</a>
  bibtex: '@inproceedings{Abdelaziz_Zeiler_Kolossa_Leutnant_Haeb-Umbach_2013, title={GMM-based
    significance decoding}, DOI={<a href="https://doi.org/10.1109/ICASSP.2013.6638984">10.1109/ICASSP.2013.6638984</a>},
    booktitle={Acoustics, Speech and Signal Processing (ICASSP), 2013 IEEE International
    Conference on}, author={Abdelaziz, Ahmed H. and Zeiler, Steffen and Kolossa, Dorothea
    and Leutnant, Volker and Haeb-Umbach, Reinhold}, year={2013}, pages={6827–6831}
    }'
  chicago: Abdelaziz, Ahmed H., Steffen Zeiler, Dorothea Kolossa, Volker Leutnant,
    and Reinhold Haeb-Umbach. “GMM-Based Significance Decoding.” In <i>Acoustics,
    Speech and Signal Processing (ICASSP), 2013 IEEE International Conference On</i>,
    6827–31, 2013. <a href="https://doi.org/10.1109/ICASSP.2013.6638984">https://doi.org/10.1109/ICASSP.2013.6638984</a>.
  ieee: A. H. Abdelaziz, S. Zeiler, D. Kolossa, V. Leutnant, and R. Haeb-Umbach, “GMM-based
    significance decoding,” in <i>Acoustics, Speech and Signal Processing (ICASSP),
    2013 IEEE International Conference on</i>, 2013, pp. 6827–6831.
  mla: Abdelaziz, Ahmed H., et al. “GMM-Based Significance Decoding.” <i>Acoustics,
    Speech and Signal Processing (ICASSP), 2013 IEEE International Conference On</i>,
    2013, pp. 6827–31, doi:<a href="https://doi.org/10.1109/ICASSP.2013.6638984">10.1109/ICASSP.2013.6638984</a>.
  short: 'A.H. Abdelaziz, S. Zeiler, D. Kolossa, V. Leutnant, R. Haeb-Umbach, in:
    Acoustics, Speech and Signal Processing (ICASSP), 2013 IEEE International Conference
    On, 2013, pp. 6827–6831.'
date_created: 2019-07-12T05:26:53Z
date_updated: 2022-01-06T06:51:07Z
department:
- _id: '54'
doi: 10.1109/ICASSP.2013.6638984
keyword:
- Bayes methods
- Gaussian processes
- convolution
- decision theory
- decoding
- noise
- reverberation
- speech coding
- speech recognition
- Bayesian decision rule
- GMM
- Gaussian mixture models
- additive noise scenarios
- automatic speech recognition systems
- convolutive noise scenarios
- decoding approach
- mathematical framework
- reverberant environments
- significance decoding
- speech feature estimation
- uncertainty-of-observation techniques
- Hidden Markov models
- Maximum likelihood decoding
- Noise
- Speech
- Speech recognition
- Uncertainty
- Uncertainty-of-observation
- modified imputation
- noise robust speech recognition
- significance decoding
- uncertainty decoding
language:
- iso: eng
page: 6827-6831
publication: Acoustics, Speech and Signal Processing (ICASSP), 2013 IEEE International
  Conference on
publication_identifier:
  issn:
  - 1520-6149
status: public
title: GMM-based significance decoding
type: conference
user_id: '44006'
year: '2013'
...
---
_id: '11816'
abstract:
- lang: eng
  text: In this paper, we consider the Maximum Likelihood (ML) estimation of the parameters
    of a GAUSSIAN in the presence of censored, i.e., clipped data. We show that the
    resulting Expectation Maximization (EM) algorithm delivers virtually biasfree
    and efficient estimates, and we discuss its convergence properties. We also discuss
    optimal classification in the presence of censored data. Censored data are frequently
    encountered in wireless LAN positioning systems based on the fingerprinting method
    employing signal strength measurements, due to the limited sensitivity of the
    portable devices. Experiments both on simulated and real-world data demonstrate
    the effectiveness of the proposed algorithms.
author:
- first_name: Manh Kha
  full_name: Hoang, Manh Kha
  last_name: Hoang
- first_name: Reinhold
  full_name: Haeb-Umbach, Reinhold
  id: '242'
  last_name: Haeb-Umbach
citation:
  ama: 'Hoang MK, Haeb-Umbach R. Parameter estimation and classification of censored
    Gaussian data with application to WiFi indoor positioning. In: <i>38th International
    Conference on Acoustics, Speech, and Signal Processing (ICASSP 2013)</i>. ; 2013:3721-3725.
    doi:<a href="https://doi.org/10.1109/ICASSP.2013.6638353">10.1109/ICASSP.2013.6638353</a>'
  apa: Hoang, M. K., &#38; Haeb-Umbach, R. (2013). Parameter estimation and classification
    of censored Gaussian data with application to WiFi indoor positioning. In <i>38th
    International Conference on Acoustics, Speech, and Signal Processing (ICASSP 2013)</i>
    (pp. 3721–3725). <a href="https://doi.org/10.1109/ICASSP.2013.6638353">https://doi.org/10.1109/ICASSP.2013.6638353</a>
  bibtex: '@inproceedings{Hoang_Haeb-Umbach_2013, title={Parameter estimation and
    classification of censored Gaussian data with application to WiFi indoor positioning},
    DOI={<a href="https://doi.org/10.1109/ICASSP.2013.6638353">10.1109/ICASSP.2013.6638353</a>},
    booktitle={38th International Conference on Acoustics, Speech, and Signal Processing
    (ICASSP 2013)}, author={Hoang, Manh Kha and Haeb-Umbach, Reinhold}, year={2013},
    pages={3721–3725} }'
  chicago: Hoang, Manh Kha, and Reinhold Haeb-Umbach. “Parameter Estimation and Classification
    of Censored Gaussian Data with Application to WiFi Indoor Positioning.” In <i>38th
    International Conference on Acoustics, Speech, and Signal Processing (ICASSP 2013)</i>,
    3721–25, 2013. <a href="https://doi.org/10.1109/ICASSP.2013.6638353">https://doi.org/10.1109/ICASSP.2013.6638353</a>.
  ieee: M. K. Hoang and R. Haeb-Umbach, “Parameter estimation and classification of
    censored Gaussian data with application to WiFi indoor positioning,” in <i>38th
    International Conference on Acoustics, Speech, and Signal Processing (ICASSP 2013)</i>,
    2013, pp. 3721–3725.
  mla: Hoang, Manh Kha, and Reinhold Haeb-Umbach. “Parameter Estimation and Classification
    of Censored Gaussian Data with Application to WiFi Indoor Positioning.” <i>38th
    International Conference on Acoustics, Speech, and Signal Processing (ICASSP 2013)</i>,
    2013, pp. 3721–25, doi:<a href="https://doi.org/10.1109/ICASSP.2013.6638353">10.1109/ICASSP.2013.6638353</a>.
  short: 'M.K. Hoang, R. Haeb-Umbach, in: 38th International Conference on Acoustics,
    Speech, and Signal Processing (ICASSP 2013), 2013, pp. 3721–3725.'
date_created: 2019-07-12T05:28:48Z
date_updated: 2022-01-06T06:51:09Z
department:
- _id: '54'
doi: 10.1109/ICASSP.2013.6638353
keyword:
- Gaussian processes
- Global Positioning System
- convergence
- expectation-maximisation algorithm
- fingerprint identification
- indoor radio
- signal classification
- wireless LAN
- EM algorithm
- ML estimation
- WiFi indoor positioning
- censored Gaussian data classification
- clipped data
- convergence properties
- expectation maximization algorithm
- fingerprinting method
- maximum likelihood estimation
- optimal classification
- parameters estimation
- portable devices sensitivity
- signal strength measurements
- wireless LAN positioning systems
- Convergence
- IEEE 802.11 Standards
- Maximum likelihood estimation
- Parameter estimation
- Position measurement
- Training
- Indoor positioning
- censored data
- expectation maximization
- signal strength
- wireless LAN
language:
- iso: eng
main_file_link:
- open_access: '1'
  url: https://groups.uni-paderborn.de/nt/pubs/2013/HoHa2013.pdf
oa: '1'
page: 3721-3725
publication: 38th International Conference on Acoustics, Speech, and Signal Processing
  (ICASSP 2013)
publication_identifier:
  issn:
  - 1520-6149
related_material:
  link:
  - description: Poster
    relation: supplementary_material
    url: https://groups.uni-paderborn.de/nt/pubs/2013/HoHa2013_Poster.pdf
status: public
title: Parameter estimation and classification of censored Gaussian data with application
  to WiFi indoor positioning
type: conference
user_id: '44006'
year: '2013'
...
---
_id: '11845'
abstract:
- lang: eng
  text: The paper proposes a modification of the standard maximum a posteriori (MAP)
    method for the estimation of the parameters of a Gaussian process for cases where
    the process is superposed by additive Gaussian observation errors of known variance.
    Simulations on artificially generated data demonstrate the superiority of the
    proposed method. While reducing to the ordinary MAP approach in the absence of
    observation noise, the improvement becomes the more pronounced the larger the
    variance of the observation noise. The method is further extended to track the
    parameters in case of non-stationary Gaussian processes.
author:
- 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: 'Krueger A, Haeb-Umbach R. MAP-based estimation of the parameters of non-stationary
    Gaussian processes from noisy observations. In: <i>IEEE International Conference
    on Acoustics, Speech and Signal Processing (ICASSP 2011)</i>. ; 2011:3596-3599.
    doi:<a href="https://doi.org/10.1109/ICASSP.2011.5946256">10.1109/ICASSP.2011.5946256</a>'
  apa: Krueger, A., &#38; Haeb-Umbach, R. (2011). MAP-based estimation of the parameters
    of non-stationary Gaussian processes from noisy observations. In <i>IEEE International
    Conference on Acoustics, Speech and Signal Processing (ICASSP 2011)</i> (pp. 3596–3599).
    <a href="https://doi.org/10.1109/ICASSP.2011.5946256">https://doi.org/10.1109/ICASSP.2011.5946256</a>
  bibtex: '@inproceedings{Krueger_Haeb-Umbach_2011, title={MAP-based estimation of
    the parameters of non-stationary Gaussian processes from noisy observations},
    DOI={<a href="https://doi.org/10.1109/ICASSP.2011.5946256">10.1109/ICASSP.2011.5946256</a>},
    booktitle={IEEE International Conference on Acoustics, Speech and Signal Processing
    (ICASSP 2011)}, author={Krueger, Alexander and Haeb-Umbach, Reinhold}, year={2011},
    pages={3596–3599} }'
  chicago: Krueger, Alexander, and Reinhold Haeb-Umbach. “MAP-Based Estimation of
    the Parameters of Non-Stationary Gaussian Processes from Noisy Observations.”
    In <i>IEEE International Conference on Acoustics, Speech and Signal Processing
    (ICASSP 2011)</i>, 3596–99, 2011. <a href="https://doi.org/10.1109/ICASSP.2011.5946256">https://doi.org/10.1109/ICASSP.2011.5946256</a>.
  ieee: A. Krueger and R. Haeb-Umbach, “MAP-based estimation of the parameters of
    non-stationary Gaussian processes from noisy observations,” in <i>IEEE International
    Conference on Acoustics, Speech and Signal Processing (ICASSP 2011)</i>, 2011,
    pp. 3596–3599.
  mla: Krueger, Alexander, and Reinhold Haeb-Umbach. “MAP-Based Estimation of the
    Parameters of Non-Stationary Gaussian Processes from Noisy Observations.” <i>IEEE
    International Conference on Acoustics, Speech and Signal Processing (ICASSP 2011)</i>,
    2011, pp. 3596–99, doi:<a href="https://doi.org/10.1109/ICASSP.2011.5946256">10.1109/ICASSP.2011.5946256</a>.
  short: 'A. Krueger, R. Haeb-Umbach, in: IEEE International Conference on Acoustics,
    Speech and Signal Processing (ICASSP 2011), 2011, pp. 3596–3599.'
date_created: 2019-07-12T05:29:22Z
date_updated: 2022-01-06T06:51:11Z
department:
- _id: '54'
doi: 10.1109/ICASSP.2011.5946256
keyword:
- Gaussian processes
- MAP-based estimation
- maximum a posteriori method
- maximum likelihood estimation
- nonstationary Gaussian processes
language:
- iso: eng
main_file_link:
- open_access: '1'
  url: https://groups.uni-paderborn.de/nt/pubs/2011/KrHa11.pdf
oa: '1'
page: 3596-3599
publication: IEEE International Conference on Acoustics, Speech and Signal Processing
  (ICASSP 2011)
status: public
title: MAP-based estimation of the parameters of non-stationary Gaussian processes
  from noisy observations
type: conference
user_id: '44006'
year: '2011'
...
---
_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'
...
