Digital Coding of Speech in Sub-bands

Crochiere, R.; Webber, S. A.; Flanagan, James L.

doi:10.1002/j.1538-7305.1976.tb02929.x

Cited by 134 publications

(53 citation statements)

References 4 publications

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“…The in between L − 1 samples are determined by interpolation. It is well known that the interpolation by L consists of two operations: up-sampling by L, and the low-pass ltering [8]. Hence, the samples y[m] appearing at the interpolator's output are to be computed by convolving the up-sampled signal {x u [m]} with the low-pass lter impulse response {h[n]}, which may be shown as in Eq.…”

Section: Interpolation (Sampling Rate Up-conversion)mentioning

confidence: 99%

Efficient Implementation of Multistage Digital Interpolators Using Half Band Filters

2013

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The process of increasing the sampling rate of any signal by a factor is known as interpolation. This paper presents the eective and ecient implementation of multistage implementation of digital interpolator using half band lters. The single stage lters are ecient for lower order interpolation factors but for higher rate change which is required in modern digital communication systems like wideband code division multiple access, worldwide interoperability for microwave access single stage implementation does not gives ecient response. For these applications a multistage implementation of the interpolator is preferred. But multistage implementation increases complexity of the overall system. This complexity can be reduced considerably by using half band lters. All this has been done with the help of the Agilent's advanced design software.

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Section: Interpolation (Sampling Rate Up-conversion)mentioning

confidence: 99%

Efficient Implementation of Multistage Digital Interpolators Using Half Band Filters

2013

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“…Increasing the number of points N = fs/Δf increases the frequency resolution but at the same time will produce smearing in the time domain due to the larger processing window. In order to increase the frequency resolution at low frequencies and retain some of the time resolution at higher frequencies, frequency subband decomposition [19][20][21] is used to generate the FTM.…”

Section: Frequency Time Matrixmentioning

confidence: 99%

Semitone frequency mapping to improve music representation for nucleus cochlear implants

Omran

Lai

Büchler

et al. 2011

J AUDIO SPEECH MUSIC PROC.

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The frequency-to-channel mapping for Cochlear implant (CI) signal processors was originally designed to optimize speech perception and generally does not preserve the harmonic structure of music sounds. An algorithm aimed at restoring the harmonic relationship of frequency components based on semitone mapping is presented in this article. Two semitone (Smt) based mappings in different frequency ranges were investigated. The first, Smt-LF, covers a range from 130 to 1502 Hz which encompasses the fundamental frequency of most musical instruments. The second, Smt-MF, covers a range from 440 to 5040 Hz, allocating frequency bands of sounds close to their characteristic tonotopical sites according to Greenwood's function. Smt-LF, in contrast, transposes the input frequencies onto locations with higher characteristic frequencies. A sequence of 36 synthetic complex tones (C3 to B5), each consisting of a fundamental and 4 harmonic overtones, was processed using the standard (Std), Smt-LF and Smt-MF mappings. The analysis of output signals showed that the harmonic structure between overtones of all complex tones was preserved using Smt mapping. Semitone mapping preserves the harmonic structure and may in turn improve music representation for Nucleus cochlear implants. The proposed semitone mappings incorporate the use of virtual channels to allow frequencies spanning three and a half octaves to be mapped to 43 stimulation channels. A pitch difference limen test was done with normal hearing subjects discriminating pairs of pure tones with different semitone intervals which were processed by a vocoder type simulator of CI sound processing. The results showed better performance with wider semitone intervals. However, no significant difference was found between 22 and 43 channels maps.

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“…(Vetterli and Gall, 1989) proposed Multiresolution Signal Analysis (MRA) technique or pyramidal algorithm. Second group (Crochiere et al, 1975;Crochiere and Sambur, 1977) proposed subband coding algorithm. Pyramidal algorithm is especially suitable and widely used in image processing applications (Mallat, 2009).…”

Section: Wavelet Based Time Frequency Algorithms a Brief Introductionmentioning

confidence: 99%

Cutting-edge Mathematical Tools in Processing and Analysis of Signals in Marine and Navy

Vujović

Šoda

Kuzmanić

2012

ToMS

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Signal processing plays a pivotal role in information gathering and decision making. This paper presents and compares different signal processing techniques used in marine and navy applications, primarily based on using wavelets as kernel. The article covers Fourier transform, time frequency wavelet based techniques such as bandelets, contourlets, curvelets, edgelets, wedgelets, shapelets, and ridgelets. In the example section of the paper, several transform techniques are presented and commented on the harbour surveillance video stream example.

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Digital Coding of Speech in Sub-bands

Cited by 134 publications

References 4 publications

Efficient Implementation of Multistage Digital Interpolators Using Half Band Filters

Efficient Implementation of Multistage Digital Interpolators Using Half Band Filters

Semitone frequency mapping to improve music representation for nucleus cochlear implants

Cutting-edge Mathematical Tools in Processing and Analysis of Signals in Marine and Navy

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