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Determination of pitch marks (PMs) is necessary in clinical voice assessment for the measurement of fundamental frequency (F0) and perturbation. In voice with ambiguous F0, PM determination is crucial, and its validity needs special attention. The study at hand proposes a new approach for PM determination from Laryngeal High-Speed Videos (LHSVs), rather than from the audio signal. In this novel approach,...
We present a novel implementation of the spectral shaping approach for artificial bandwidth extension (ABE). The spectral envelope in the missing band is adaptively tuned by a set of controlled subband powers predicted by a feedforward neural network (FFNN) in conjunction with the use of spline interpolation. There are three main aspects to this study: First, objective quality measures are exploited...
Delay jitter in packet-switched networks has to be compensated by a playout buffer. The playout buffer algorithm plays an important role in real-time applications such as VoIP, in this, paper we introduce a method based on truncated Gaussians to calculate the playout delay for VoIP application. Our method out-performs the existing methods both in term of residual delay and packet loss. This method...
We present an algorithm to decompose speech into transient and non-transient components. Our algorithm, the joint time-frequency segmentation algorithm, uses the wavelet packet coefficients of the speech signal and represents them as tiles of a time-frequency representation adapted to the characteristics of the signal itself. Any wavelet packet coefficient, whose tiling height is larger than or equal...
Digital compensation of nonlinear systems is an important topic in many practical applications. This paper considers the problem of predistortion of nonlinear systems described using Volterra series by connecting in tandem an adaptive Volterra predistorter. The suggested direct learning architecture (DLA) approach utilizes the spectral magnitude matching (SMM) method that minimizes the sum squared...
Predistortion of parallel wiener-type systems is considered in this paper. The predistorter is first modeled as a Volterra series. In order to reduce computation complexity, a simplified predistorter model constructed using adaptive FIR filters is proposed. The coefficients of these two suggested predistorters are estimated using the nonlinear filtered-x least mean squares (NFtimesLMS) algorithm based...
This paper addresses the question of temporal learning in spatially distributed wireless sensor networks (WSN). We propose to fuse WSNs with the echo states network learning concepts to infer the spatio-temporal dynamics of the data collaboratively measured by sensors. We prove that a WSN topology described by a bidirected graph is strongly connected, which is a sufficient and necessary condition...
Human perception of Voice- and Video-over-IP connection quality is influenced by a lot of factors, first of all the network conditions like packet loss rate, delay and jitter but also others like the hard- and software (speech or video codec) in use. In this paper an experimental setup is developed which allows adjustment of certain network parameters to study their impact on the perceived conversational...
De-jitter buffer adds extra delay in real-time communications. An incomplete information of delay statistics makes design of de-jitter buffer hard. In this paper we propose maximum entropy method to calculate playout time for packets. We derive expression for delay distribution based on principle of maximum entropy and then calculate mean and variance of delay using packet delay percentile information...
We propose an improved noise reduction method for robust speech recognition based on a perceptually statistical wavelet filtering algorithm. Perceptual noise thresholds are estimated from the universal thresholds for each critical wavelet subband. Fast changes of background noise are tracked adaptively by improving our statistical percentile filtering method. Smoothed wavelet shrinkage is applied...
Mixed-signal systems combine analog and digital signal processing in one overall design that should be integrated as a single system on chip. At system level, the separation into isolated subsystem representations for analog and digital parts needs to be overcome by a unified formalism that can handle any mix of continuous-time, discrete-time, and hybrid systems. A second driving force in our contribution...
In this paper an enhanced noise reduction for robust speech recognition is implemented by means of a perceptual wavelet filtering algorithm. The psychoacoustic model is applied to map the universal thresholds to the perceptually universal thresholds for each critical wavelet subband. By improving our quantile filtering method, the change of noise level is tracked more adaptively. The denoising algorithm...
Distortion compensation of nonlinear systems is an important topic in many practical applications. This paper concerns with linearization of nonlinear systems which can be modeled using Volterra series by connecting two adaptive nonlinear Volterra filters. The first one is a training filter connected in parallel with the nonlinear system and its kernels are estimated recursively. The second adaptive...
This paper addresses parameter estimation of superimposed signals jointly with their number within the Bayesian framework. We combine sparse Bayesian machine learning methods with the state of the art SAGE-based parameter estimation algorithm. Existing sparse Bayesian methods allow to assess model order through priors over model parameters, but do not consider models nonlinear in parameters. SAGE-based...
Nonlinear behavioral models are advantageously used in system-level simulations to predict the generated distortion without the full computationally complexity of transistor- based circuit simulations. Such models are often described by two static nonlinearities called AM/AM and AM/PM-conversion. Because the modeling with purely static nonlinearities is not sufficient for wideband applications (no...
Wireless systems are subject to fading - time variations of the receiving conditions caused by multipath propagation and transceiver movements. Prediction of fading allows to 'learn' the channel state information (CSI) in advance and adjust the transmission scheme accordingly. In this contribution we consider a framework to handle predictions of general fast- and non-flat fading MIMO wireless channels...
RF power amplifiers (PA) of wireless communication systems are usually driven in their nonlinear region to obtain a higher efficiency. The price paid for the increased efficiency is the distortion of the transmission signal. To fulfill a given spectral mask for the transmission signal and to avoid an unacceptable high bit-error rate on the receiver side, the amplifier must be linearized. If wideband...
In this paper we address the application of a denoising algorithm based on wavelet packet decomposition and quantile noise estimation to noise suppression for automatic speech recognition. The denoising algorithm is adapted to suit the different requirements in machine recognition, as compared to human perception, and is tested in combination with state-of-the-art speech recognition systems. The results...
Wireless systems are subject to fading-time variations of the receiving conditions caused by multipath propagation and transceiver movements. Prediction of fading allows to 'learn' the channel state information (CSI) in advance and adjust the transmission scheme as required based on the future values of CSI. In this contribution we propose a framework to handle predictions of general fast- and non-flat...
We introduce a novel randomization method for time-interleaved analog-to-digital converters (TIADCs). In contrast to conventional randomization methods our method improves the signal-to-noise and distortion ratio (SINAD) and the spurious free dynamic range (SFDR) by combining randomization of channel ADCs and spectral shaping of timing mismatches. The new method can exploit information about timing...
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