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This paper presents a deterministic space-time multipath Rayleigh fading channel model to study space-time correlation of the received signal waveforms to multi-antenna array receiver system. It can be considered as a modification of Lee's model, which is based on vector sum of fading waveforms, incorporating azimuth spread, time delay along the array, scatterers' location geometry and number of scatterers'...
Multiparty meetings common to many business environments often have participants who are generally stationary. Hence, active speakers can be disambiguated by location, and meeting analysis research groups have proposed the use of speaker location information (spatial cues) for meeting segmentation and higher level analysis. As the cues are estimated from multi-microphone recordings, this paper studies...
Several low frequency radio astronomy arrays are currently under development. For example the LOFAR array (with 13,000 dipole elements) will operate in the frequency range of 20MHz–240Mhz. At these frequencies the effect of the ionosphere cannot be ignored. Due to the fact that the size of the array is larger than the size of the irregularities in the ionosphere the calibration problem is direction...
This paper deals with high resolution bearing estimation in urban radiocommunication scenarii. Indeed, in such environments, scatterers local to the emitter engender diffuse paths that deteriorate the performances of conventional subspace-based algorithms. A deconvolution technique, involving Linear Prediction methods, is designed to characterize so called distributed sources by returning the mean...
In this paper, we present a method for estimating the signal sources steering vector using an arbitrary planar array with omnidirectional elements. The proposed method improves the initial estimation of the signal steering vector in two steps. In the first step of this algorithm we minimize of the distance between the steering vector and the signal subspace. The second step improves the estimation...
Top-k document retrieval, which returns highly relevant documents relative to a query, is an essential task for many applications. One of the promising index frameworks is built by FM-index and wavelet tree for supporting efficient top-k document retrieval. The index, however, has difficulty on handling document frequency (DF) at search time because indexed terms are all substrings of a document collection...
In this paper, we present a fast algorithm of time synchronization between User Equipment (UE) and Base Station (BS) which is suitable for Long Term Evolution (LTE) Random Access Channel (RACH). The algorithm reduces the complexity more than 1.5 times. Further, if the SNR is above a threshold, the algorithm allows to extremely reduce the complexity of synchronization more than 3 times. The presented...
Robot audition systems are expected to support a variety of civilian and rescue applications in hazardous situations. Sensed data can only be interpreted meaningfully when referenced to the location of the sensor, making localization an important area of research. In this paper, we have developed sound source localization system for our Fire Bird VI robot. Localization algorithms like cross correlation...
Depth estimation is one of the new functions provided by hand-held light field cameras. However, the quality of depth estimation is very sensitive to noise, which is especially a problem for scenes under low light conditions. In this paper, we propose a depth estimation flow for light field data, which can be fully-automated and no noise characteristics are required a priori. The results of Root Mean...
Active Speaker Detection(ASD) in a noisy environment is a challenging problem. Audio modality does not help significantly when the level of noise is high, so usage of bimodal information like vision and speech together for ASD in a meeting room scenario is explored in this work. The method proposed in this work uses an audio-visual sensor array placed in circular geometry. Time difference of arrival(TDOA)...
This paper studies the application of MUtiple Signal Classification (MUSIC) algorithm on Multiple Measurement Vector (MMV) problem for the purpose of frequency parameter estimation while s true frequencies are located in the continuum of a bounded domain and sensors are randomly selected from a Uniform Linear Array (ULA). The MUSIC algorithm amounts to identifying a noise subspace from measurements,...
In this paper we propose a systematic method to estimate SRAM array yield considering spatially-correlated process variation. Although many parameter variations have been shown to be spatially-correlated, this phenomenon has been neglected in SRAM yield estimation due to its small impact for small SRAMs. However, its impact on array yield is significant for SRAM arrays of realistic sizes. In this...
This paper presents a computationally efficient Direction-Of-Arrival (DOA) estimation algorithm by Uniform Linear Array (ULA), which is effective for highly-correlated sources but also works for uncorrelated sources. The proposed algorithm is basically based on the relation between the elements of array covariance matrix, does not need eigendecomposition, iteration or angular peak-search, and leads...
An efficient direction of arrival (DOA) estimation of multiple electromagnetic sources by using artificial neural network (ANN) approach is presented in the paper. Electromagnetic sources considered here are of stochastic radiation nature, mutually uncorrelated and at arbitrary angular distance. The approach is based on training of the ANN in which the calculation of correlation matrix in the far-field...
After over two decades of extensive research on branch prediction, branch mispredictions are still an important performance/power bottleneck for today's aggressive processors. In our prior work, to further understand the causes for mispredictions, we presented a source-code based classification of branch mispredictions extending the prior work on predictor-specific classification. Since source-code...
Different from phased-array radar, multiple-input multiple-output (MIMO) radar with colocated antennas would illuminate waveforms with different signatures into different spatial directions. In this paper, we study the waveform design problem for colocated MIMO radar and state the necessity to suppress sidelobes of returns of possible targets rather than the waveforms illuminated from antennas. A...
In the production and manufacturing industries, speed measurement plays a significant part in condition monitoring and motion control of mechanical machinery. During operation, the friction between the sliding part and the air generates electrostatic charge that can be used for measurement of the linear speed. This paper deals with non-contact measurement of strip speed using electrostatic sensing...
Large-scale antenna systems provide a promising way to increase spectral and energy efficiency with a very large number of antennas at the base station serving many tens of users simultaneously. However, to a large extent, the theoretical performance relies on some fundamental assumptions of the radio environment, which need to be validated in realistic propagation scenarios. In this study we focus...
In this paper, we have chronicled the development of sound localization system based on TDOA (Time Difference of Arrival). Acoustic Source Localization (ASL) is a technique used to track and locate the exact location of a sound source using an array of microphones. The concept of ASL uses sound signals captured from an array of microphones and they are processed using TDOA localization method to estimate...
This paper addresses sound source detection in an outdoor environment using a quadrotor with a microphone array. Since the previously reported method has a high computational cost, we proposed a sound source detection algorithm called MUltiple SIgnal Classification based on incremental Generalized Singular Value Decomposition (iGSVD-MUSIC), which detects sound source location and temporal activity...
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