Browsing by Subject "Electric filters"
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Item Item Blind source separation of speech signals using filter banks(Texas Tech University, 2002-08) Patterson, Andrew J.The aim of this thesis is to improve the perceived quality of digital hearing aids through the introduction of source segregation algorithms that attenuate undesired speech and noise into the psychoacoustic model of the human ear. It proposes the use of low-delay modulated filter banks to mimic the critical bands of the human ear to accomplish blind source separation. This thesis will cover theory and results for modulated filter banks and blind source separation.Item Effects of IF filter characteristics on angle modulation distortion(Texas Tech University, 1971-05) Williams, Oscar EugeneNot availableItem Efficient realization of biorthoganal [sic] fixed point cosine modulated filter banks(Texas Tech University, 2002-12) Casey, Ryan B.Cosine modulated filter banks are widely researched and used in signal compression because they can provide perfect reconstruction (PR) while maintaining a low computational cost. Their ability to provide PR can be hindered by the device that they are implemented on. Fixed-point digital signal processors require that the filter coefficients be quantized, force resultants to be rounded, and are subject to overflow. All three can lead to reconstruction errors. For the filter bank to preserve its PR properties, its realization structure must be robust to these three sources of error. This structure is then implemented on a fixed-point device, such as a TI C6201 DSP without losing a valuable property. This is validated in this thesis along with showing that the frequency response of the filters is upheld by this structure through the use of Matlab simulations supported by a DSP implementationItem Generalized optical linear filtering of one-dimensional signals(Texas Tech University, 1985-08) Blanchard, Lorena AnnNot availableItem Optimal circuit design with a sensitivity penalty.(Texas Tech University, 1974-12) Chau, Thieu-HungNot availableItem Oversampled filter banks with built-in error correction capabilities(2012-05) Shamanna, Arun; Karp, Tanja; Nutter, BrianDuring recent years, oversampled filter banks with perfect reconstruction (PR) have become very popular as they provide increased design freedom for the filters, allow higher attenuation in the stop-band and also provide a very good noise immunity. The goal of this thesis is to design oversampled filter banks with builtin error correction capabilities as presented in [16] and extend the error correction scheme for multiple impulse errors. We intend to compare the performance of traditional channel coding with critically sampled filter banks (Modified DFT filter banks [6]) versus joint source channel coding using oversampled filter banks. The set up is tested on memoryless channels that corrupt the bits during the transmission causing impulse errors [14] for a speech-like input signal (AR1 process). We anticipate that the redundancy introduced by oversampled filter banks not only provides reliable communication like channel codes but also leads to the improvement in the quality of the reconstructed signal.Item Space domain suppression of film-grain noise(Texas Tech University, 1975-05) Abbott, Barton LewisNot availableItem