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Detail
Journal Article
Online Blind Channel Normalization Using BPF-Based Modulation Frequency Filtering
- Authors
- Yun-Kyung Lee, Ho-Young Jung, Jeon Gue Park
- Issue Date
- 2016-12
- Citation
- ETRI Journal, v.38, no.6, pp.1190-1196
- ISSN
- 1225-6463
- Publisher
- 한국전자통신연구원 (ETRI)
- Language
- English
- Type
- Journal Article
- Abstract
- We propose a new bandpass filter (BPF)-based online channel normalization method to dynamically suppress channel distortion when the speech and channel noise components are unknown. In this method, an adaptive modulation frequency filter is used to perform channel normalization, whereas conventional modulation filtering methods apply the same filter form to each utterance. In this paper, we only normalize the two mel frequency cepstral coefficients (C0 and C1) with large dynamic ranges; the computational complexity is thus decreased, and channel normalization accuracy is improved. Additionally, to update the filter weights dynamically, we normalize the learning rates using the dimensional power of each frame. Our speech recognition experiments using the proposed BPF-based blind channel normalization method show that this approach effectively removes channel distortion and results in only a minor decline in accuracy when online channel normalization processing is used instead of batch processing.
- KSP Keywords
- Batch Processing, Computational complexity, Filtering method, Mel-frequency Cepstral Coefficient(MFCC), Modulation frequency, Noise components, Normalization method, adaptive modulation, bandpass filter(BFP), channel noise, channel normalization