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8 results on '"time-domain processing"'

1. High‐resolution time delay estimation via sparse parameter estimation methods.

Author

Park, Hyung‐Rae and Li, Jian

Abstract

This study addresses the high‐resolution time delay estimation (TDE) via sparse parameter estimation methods. Two representative algorithms, Sparse Asymptotic Minimum Variance (SAMV) and SParse Iterative Covariance‐based Estimation are devised in both the time and frequency domains for application to the TDE of spread‐spectrum signals and their performances are analysed in various multipath environments. The authors also proposes the combined approach of SAMV and weighted RELAX, referred to as SAMV‐WRELAX, to reduce the computational load. Numerical examples demonstrate that the frequency‐domain approaches with a proper type of snapshots not only outperform the corresponding time‐domain approaches but also mitigate the problem of the noise correlation encountered in time‐domain processing. They also show that the computational load of SAMV‐WRELAX with a grid size of 0.1Tc decreases up to a few tenths of that of SAMV with a fine grid, e.g. a size of 0.01Tc, without any performance degradations. [ABSTRACT FROM AUTHOR]

Published
2020
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2. An Improved Azimuth Angle Estimation Method with a Single Acoustic Vector Sensor Based on an Active Sonar Detection System.

Author

Anbang Zhao, Lin Ma, Xuefei Ma, and Juan Hui

Subjects
*AZIMUTH, *ESTIMATION theory, *SONAR detection, *COMPUTER simulation, *MATCHED filters
Abstract

In this paper, an improved azimuth angle estimation method with a single acoustic vector sensor (AVS) is proposed based on matched filtering theory. The proposed method is mainly applied in an active sonar detection system. According to the conventional passive method based on complex acoustic intensity measurement, the mathematical and physical model of this proposed method is described in detail. The computer simulation and lake experiments results indicate that this method can realize the azimuth angle estimation with high precision by using only a single AVS. Compared with the conventional method, the proposed method achieves better estimation performance. Moreover, the proposed method does not require complex operations in frequency-domain and achieves computational complexity reduction. [ABSTRACT FROM AUTHOR]

Published
2017
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3. Low-Complexity PAPR Reduction Scheme Without Side Information for OFDM Systems.

Author

Eom, Seung-Sik, Nam, Haewoon, and Ko, Young-Chai

Subjects
*ORTHOGONAL frequency division multiplexing, *TIME-domain analysis, *MEAN square algorithms, *AMPLITUDE modulation detectors, *BIT error rate measurement, *RAYLEIGH fading channels, *FOURIER transforms, *DATA transmission systems
Abstract

This paper proposes a novel peak to average power ratio (PAPR) reduction scheme that requires no side information in orthogonal frequency division multiplexing (OFDM) systems. Unlike the selective mapping (SLM) or the partial transmit sequence (PTS) scheme, the proposed scheme deals with post inverse fast Fourier transform (IFFT) symbols and thus requires only a single IFFT processor in the transmitter. Compared to other conventional schemes implemented with a single IFFT processor, such as the circularly shifted phase sequences (CSPS) or the optimised circularly shifted phase sequences (OCSPS) method, the proposed scheme achieves an even lower complexity since only phase rotation and cyclic shifting of OFDM symbols are performed. More importantly, the proposed scheme significantly outperforms the CSPS and the OCSPS methods in reducing PAPR as shown in simulation results. An added benefit of the proposed scheme is that it employs a linear receiver, such as a maximal likelihood (ML) detector, a minimum mean square error (MMSE) estimator, or a zero forcing (ZF) estimator, to demap quadrature amplitude modulation (QAM) symbols. Especially the ML detector demaps the QAM symbols with no side information. Simulation results also show that the bit error rate (BER) of the proposed scheme has no loss when the ML detector, the ZF or the MMSE estimator is used with hard-decision compared to that of the conventional OFDM system without any PAPR reduction scheme over Rayleigh fading channel. [ABSTRACT FROM PUBLISHER]

Published
2012
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4. A Low-Complexity Time-Domain Linear Symbol Combining Technique for PAPR Reduction in OFDM Systems.

Author

Alsusa, Emad and Lin Yang

Subjects
*ORTHOGONAL frequency division multiplexing, *FOURIER transforms, *DIGITAL signal processing, *ERRORS, *ERROR rates, *RADIO transmitter-receivers, *POWER spectra, *DIGITAL communications, *DATA transmission systems
Abstract

High peak-to-average-power ratio (PAPR) is a particular disadvantage of orthogonal frequency-division multiplexing (OFDM) systems and can significantly degrade the power efficiency at the transmitter. The aim of this paper is to propose a post-inverse fast Fourier transform (IFFT) PAPR reduction method based on intelligent linear symbol combining with the objective to minimize the PAPR at the transmitter. Unlike the methods so far reported in the literature, the proposed method has a relatively low complexity and does not require external randomization sequences. This paper will also investigate the impact of the proposed method on the system's bit error rate (BER) performance and provide a closed-form analytical expression that takes into account the BER dependency on the side information bits and multiblock combination. It will be shown that the proposed technique can provide significant PAPR reductions at manageable levels of signal processing requirements while the BER degradation is relatively small. [ABSTRACT FROM AUTHOR]

Published
2008
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5. Bayesian time-domain multiple sound source localization for a stochastic machine

Author

Emmanuel Mazer, Laurent Girin, Marvin Faix, Raphael Frisch, Jacques Droulez, Techniques of Informatics and Microelectronics for integrated systems Architecture (TIMA), Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA), Interaction située avec les objets et environnements intelligents (PERVASIVE), Inria Grenoble - Rhône-Alpes, Institut National de Recherche en Informatique et en Automatique (Inria)-Institut National de Recherche en Informatique et en Automatique (Inria)-Laboratoire d'Informatique de Grenoble (LIG), Université Pierre Mendès France - Grenoble 2 (UPMF)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut National Polytechnique de Grenoble (INPG)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Université Pierre Mendès France - Grenoble 2 (UPMF)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut National Polytechnique de Grenoble (INPG)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA), Institut des Systèmes Intelligents et de Robotique (ISIR), Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), CRISSP (GIPSA-CRISSP), Département Parole et Cognition (GIPSA-DPC), Grenoble Images Parole Signal Automatique (GIPSA-lab), Université Pierre Mendès France - Grenoble 2 (UPMF)-Université Stendhal - Grenoble 3-Université Joseph Fourier - Grenoble 1 (UJF)-Institut Polytechnique de Grenoble - Grenoble Institute of Technology-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Université Pierre Mendès France - Grenoble 2 (UPMF)-Université Stendhal - Grenoble 3-Université Joseph Fourier - Grenoble 1 (UJF)-Institut Polytechnique de Grenoble - Grenoble Institute of Technology-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Grenoble Images Parole Signal Automatique (GIPSA-lab), Université Pierre Mendès France - Grenoble 2 (UPMF)-Université Stendhal - Grenoble 3-Université Joseph Fourier - Grenoble 1 (UJF)-Institut Polytechnique de Grenoble - Grenoble Institute of Technology-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Université Pierre Mendès France - Grenoble 2 (UPMF)-Université Stendhal - Grenoble 3-Université Joseph Fourier - Grenoble 1 (UJF)-Institut Polytechnique de Grenoble - Grenoble Institute of Technology-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-GIPSA Pôle Parole et Cognition (GIPSA-PPC), Université Pierre Mendès France - Grenoble 2 (UPMF)-Université Stendhal - Grenoble 3-Université Joseph Fourier - Grenoble 1 (UJF)-Institut Polytechnique de Grenoble - Grenoble Institute of Technology-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Université Pierre Mendès France - Grenoble 2 (UPMF)-Université Stendhal - Grenoble 3-Université Joseph Fourier - Grenoble 1 (UJF)-Institut Polytechnique de Grenoble - Grenoble Institute of Technology-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA), Techniques de l'Informatique et de la Microélectronique pour l'Architecture des systèmes intégrés (TIMA), Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), Institut National de Recherche en Informatique et en Automatique (Inria)-Institut National de Recherche en Informatique et en Automatique (Inria)-Laboratoire d'Informatique de Grenoble (LIG ), Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), GIPSA - Cognitive Robotics, Interactive Systems, & Speech Processing (GIPSA-CRISSP), Grenoble Images Parole Signal Automatique (GIPSA-lab ), Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut Polytechnique de Grenoble - Grenoble Institute of Technology-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut Polytechnique de Grenoble - Grenoble Institute of Technology-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Grenoble Images Parole Signal Automatique (GIPSA-lab ), and Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut Polytechnique de Grenoble - Grenoble Institute of Technology-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut Polytechnique de Grenoble - Grenoble Institute of Technology-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])

Subjects
[INFO.INFO-AR]Computer Science [cs]/Hardware Architecture [cs.AR], Signal processing, Computer science, Bayesian probability, 020206 networking & telecommunications, Statistical model, specific hardware, 02 engineering and technology, Acoustic source localization, Bayesian stochastic machine, time-domain processing, Bayesian inference, Robustness (computer science), [INFO.INFO-SD]Computer Science [cs]/Sound [cs.SD], 0202 electrical engineering, electronic engineering, information engineering, 020201 artificial intelligence & image processing, Multiple sound source localization, Time domain, Algorithm, ComputingMilieux_MISCELLANEOUS
Abstract

We propose a time-domain multiple sound source localization (SSL) method based on Bayesian inference. This method is specifically designed to run on the stochastic machines (SM) that we are currently developing to perform efficient low-level sensor signal processing with ultra-low power consumption. The proposed SSL method is divided into two main parts. First, a probabilistic model is run on 50 very short time frames (3. 75ms each) of multichannel recorded signals. Second, the results obtained on the different frames are fused to obtain a final localization map. Using the system in a supervised way allows to extract estimated source locations by selecting as many maxima as there are sources in the room. We explain how this method is implemented on a SM. Experiments are presented to illustrate the performance and robustness of the resulting system.

Published
2019
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6. A novel approach to acoustic liquid density measurements using a buffer rod based measuring cell

Author

E. Bjorndal, K.-E. Froysa, and S.-A. Engeseth

Subjects
Acoustics and Ultrasonics, Microfluidics, law.invention, Pulse-echo mode, law, Reflection coefficient, Instrumentation, Equipment Design, Acoustic impedance, Pressure measurement, Transducer, Frequency domain, Buffer rod based measuring, Acoustic liquid density measurements, Density measurement, Algorithms, Density span, Domain integration signal processing approach, Materials science, Manometry, Time-domain processing, Acoustics, Transducers, Liquid transmission path, Sensitivity and Specificity, Specimen Handling, Time-domain analysis, Acoustic transducers, Optics, Calibration, Frequency-domain analysis, Electrical and Electronic Engineering, Distilled water, Interference reduction, Matematikk og Naturvitenskap: 400::Fysikk: 430 [VDP], Special density calibration oil qualities, business.industry, Attenuation, Transducer arrangement, Reproducibility of Results, Water, Equipment Failure Analysis, Acoustic measurement, Echo amplitudes, Pressure reflection coefficient measurement, l2-norm frequency, Ultrasonic sensor, Cell, business, Oils, Liquid acoustic impedance measurement, Densitometry
Abstract

A new method for measuring the pressure reflection coefficient in a buffer rod configuration is presented, together with experimental results for acoustic measurements of the liquid density, based on the measurement of the liquid's acoustic impedance. The method consists of using 2 buffers enclosing the liquid in a symmetrical arrangement with a transducer fixed to each buffer. One of the transducers is used in a pulse-echo mode while the other transducer operates as a receiver. The echo amplitudes leading to the pressure reflection coefficient as found by this method possess advantages such as reduced attenuation due to a shorter liquid transmission path and reduced interference, as compared with the ABC method. Measurements with distilled water and with special density calibration oil qualities have been performed using both the new method and the ABC method and are shown for the new method to give a density span within +/- 0.15% of the reference values. A comparison of the measured densities based on both a time-domain and a l(2)-norm frequency domain integration signal processing approach is given, along with a recommendation as to how the signal processing should be performed.

Published
2008
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7. A distributed approach to efficient time-domain SAR processing

Author

M. Jager, H. Przybyl, Andreas Reigber, Ronny Hänsch, Pau Prats, M. Weber, and A. Dietzsch

Subjects
Java, business.industry, Computer science, Distributed computing, Process (computing), Software development, Image processing, time-domain processing, Institut für Hochfrequenztechnik und Radarsysteme, Domain (software engineering), motion compensation, Factor (programming language), Computer graphics (images), Scalability, distributed processing, Time domain, business, computer, SAR processing, SAR-Technologie, computer.programming_language
Abstract

This paper presents a distributed approach for time- domain focusing, which significantly enhances the overall efficiency by distributing the computational load across a (potentially large) number of networked computers. The system described includes the so-called master, responsible for pre-processing, the distribution of fragments of raw-data data and the collection of processed image fragments. Fragments of raw-data are passed to so-called slaves, any number of which can be connected to the master, which are responsible for the focusing itself. Master and slave actively communicate over the network to organise the entire process in a scalable manner. In this way, time-domain processing can be accelerated by a factor that is virtually linear in the number of participating slaves. This paper summarises the current status of software development, realised in a platform-independent way using the IDL and Java languages. Additionally, some preliminary evaluations of performance, scalability and the required network infrastructure are given. Some examples of SAR data, acquired by the airborne sensor E-SAR of DLR, and processed with the system described are shown.

Published
2007
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8. MIMO-OFDM channel estimation - a pilot sequence design for time-domain processing

Author

Ribeiro, C. and Atilio Gameiro

Subjects
MIMO, pilot sequence design, ComputerSystemsOrganization_COMPUTER-COMMUNICATIONNETWORKS, pilot-aided channel estimation, Data_CODINGANDINFORMATIONTHEORY, time-domain processing, Computer Science::Information Theory, OFDM
Abstract

A pilot sequence design for MIMO-OFDM systems is investigated where all transmit antennas share the same sub-carriers to convey pilot symbols. The pilot sequences are endowed with phase-shifting properties, granting the receiver the possibility of extracting the impulse responses for all channels directly from the antennas’ time-domain received signals, without co-channel interference. A linear processing of the timedomain samples is all that is needed to get the channel impulse responses, resulting in an algorithm with very low computational load. The feasibility of the investigated method is substantiated by system simulation using indoor and outdoor broadband wireless channel models.

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