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In this paper, the Artificial Neural Network (ANN) paradigm is applied to radar target classification. Radar returns are simulated via an e.m code and time-domain polarimetric target features are extracted by means of Prony's algorithm. Two different type of feedforward neural network has been adopted in order to classify the target echo, namely the Multi Layer Perceptron (MLP) and the Self Organizing...
The paper presents a very simple enhancement of joint coding of stereo and surround channels within a perceptual audio codec. Moreover, the paper proposes two improvements to standard parametric stereo and spatial audio compression in order to avoid the smearing of transients in the process of channel downmixing. The improvements consist in compensating of inter-channel delays prior to mixdown, as...
In this paper a new method of speech segmentation is suggested. It is based on power fluctuations of the wavelet spectrum for a speech signal. In most approaches to speech recognition, the speech signals are segmented using constant-time segmentation. Constant segmentation needs to use windows to decrease the boundary distortions. A more natural approach is to segment the speech signals on the basis...
In this paper, a system for reliable communication of coded grey-level face images over noisy channels is proposed. Principal Component Analysis (PCA) is used for face image coding and an unequal error protection (UEP) joint source channel coding scheme is proposed for mobile communication applications. Coded images are protected with convolutional codes for transmission over mobile channels. Recognition...
Synchrotron radiation 3D micro-CT providing quantitative images of bone samples opens new perspectives for assessing bone metabolism. The purpose of this paper is to evaluate the possibility of segmenting remodeling regions from such images acquired at a spatial resolution of 10 µm. Segmenting remodeling regions within the bone phase is not an easy task. Although remodeling regions can be visually...
Turbo equalization and frequency-domain equalization (FDE) have both been proved to be effective to combat frequency-selective fading channels. By combining the two techniques, we propose a low complexity Turbo space-frequency equalization (TSFE) structure for single-carrier (SC) multiple input multiple output (MIMO) systems, which provides close performance to its full complexity version with a huge...
Recently, we have proposed a particle filtering-type methodology, which we refer to as cost-reference particle filtering (CRPF). Its main feature is that it is not based on any particular probabilistic assumptions regarding the studied dynamic model. The concepts of particles and particle streams, however, are the same in CRPF as in standard particle filtering (SPF), but the probability masses of...
Wyner-Ziv (WZ) video coding - a particular case of distributed video coding (DVC) - is a new video coding paradigm based on two major Information Theory results: the Slepian-Wolf and Wyner-Ziv theorems. Recently, practical WZ video coding solutions were proposed with promising results. Many of the solutions available in the literature make use of a feedback channel (FC) to perform rate control at...
A novel color histogram equalization approach is proposed that not only takes into consideration the correlation between color components in the color space, but it is also enhanced by a multi-level smoothing technique adopted from the field of language modeling. In this way, the correlation between color components is taken into account and the problem of unseen values for a color component, either...
This paper describes an investigation into the repair of continuous tracheoesophageal (TE) speech. Our repair system resynthesises TE speech using a synthetic glottal waveform, reduces its jitter and shimmer and applies a novel spectral smoothing and tilt correction algorithm, derived from a comparative study of normal and TE spectral envelopes. The perceptual enhancement achieved by each correction...
We consider the problem of estimating a parameter θ of a signal s(x; θ) corrupted by noise when only 1-bit precision samples are allowed. We propose and analyze a new estimator based on dithered 1-bit samples. Our estimate is consistent and satisfies an asymptotic CLT for a wide class of dither distributions. In particular, uniformly distributed dither leads to only a logarithmic rate loss compared...
In this paper, we focus on a cellular system with M transmit antennas at the base station (BTS) and one receive antenna at the mobile (i.e. an M-input/single-output (MISO) channel), where the BTS commands each mobile to transmit its channel state information back to the BTS. Our main result is a specific feedback scheme with adaptive bit allocation, where a binary tree-structured vector quantizer...
Discrete multitone (DMT) systems have been widely adopted in broadband communications. When the transmission channel is frequency selective, there will be interblock interference (IBI). IBI can be avoided by zero-padding (ZP) [1]. Another solution is to allow IBI during transmission, and at the receiver the samples that contain IBI are removed by zero-jamming (ZJ) [2]. The ZP DMT system employs the...
Orthogonal frequency division multiplexing (OFDM) provides a viable solution to communicate over frequency selective fading channels. However, in the presence of frequency nulls in the channel response, the uncoded OFDM faces serious symbol recovery problems. As an alternative to previously reported error correction techniques in the form of pre-coding for OFDM, we propose the use of post-coding of...
A high speed VLSI image sensor including some preprocessing algorithms is described in this paper. The sensor implements some low-level image processing in a massively parallel strategy in each pixel of the sensor. Spatial gradients, various convolutions as Sobel or Laplacian operators are described and implemented on the circuit. Each pixel includes a photodiode, an amplifier, two storage capacitors...
Since the downlink has a difficult algebraic structure, it is more convenient to switch to the dual uplink problem which has better algebraic properties. We consider the uplink/downlink duality with respect to the mean square error (MSE), where our system model is as general as possible, i.e., we allow not only for correlations of the symbols and noise, but also model the precoders, the channels,...
Digital multimedia content (especially audio) is becoming a major part of the average computer user experience. Large digital audio collections of music, audio and sound effects are also used by the entertainment, music, movie and animation industries. Therefore, the need for identification and management of audio content grows proportionally to the increasing widespread availability of such media...
Sequential Monte Carlo (SMC) schemes have been recently proposed in order to perform optimal equalization of multiple input multiple output (MIMO) wireless channels. The main feaures of SMC techniques that make them appealing for the equalization problem are (a) their potential to provide asymptotically optimal performance in terms of bit error rate and (b) their suitability for implementation using...
This paper presents the design ofWARP, a custom platform for research in advanced wireless algorithms and applications. The platform consists of both custom hardware and FPGA implementations of key communications blocks. The hardware consists of FPGA-based processing boards coupled to wideband radios and other I/O interfaces; the algorithm implementations already include a flexible OFDM physical layer...
To minimize the risks involved in humanitarian demining requires a sensitivity setting close to unity, resulting in a very high false alarm rate. Nuclear quadrupole resonance detection, based on the spin echoes from nuclear spin relaxation, is a promising example of a highly specific detector that directly addresses the properties of the explosive rather than the mine casing. However, the data aquisition...
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