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International conference on Acoustics, Speech, and signal processing (ICASSP)

作者： F.T. Moller J.B. Andersen H.R. Jensen O. Olsen F.K. Fink Institute for Electronic Systems University of Aalborg Aalborg Denmark

This paper describes PSEUDEC, a dedicated co-processor and the rationale behind its design. The final goal of our work is to present a single chip solution with low power consumption for an advanced digital hearing aid based on a parameterized transformation of speech (PARTRAN). Characterization of the constituent parts of the PARTRAN algorithm shows that it is well suited for implementation on a heterogeneous architecture. The design strategy used identifies a subset for implementation on dedicated hardware, with a computational complexity roughly equivalent to the performance of a standard 10 MIPS DSP. The subset of PARTRAN implemented by PSEUDEC performs pseudo-decomposition of a 12th order LPC polynomial. An adapted algorithm displays improved dynamic range compared to the conventional solution for DSPs, calculating the amplitude spectrum rather than the power spectrum. Highly pipelined CORDIC-units optimized for the application replaces complex multiplication, trigonometric operations (for e/sup j/spl omega//) and square root (for |a|=/spl radic/(a/sub r//sup 2/+a/sub i//sup 2/)), exploiting the power of CORDIC operations in advanced DSP algorithms. PSEUDEC uses redundant data representation and bit-serial arithmetic, most significant digit first (on-line arithmetic) for efficient implementation of operators and for efficient (inter-operator) communication. The inherent nature of on-line arithmetic and the operators used allows for fast and efficient implementation even when using ordinary standard cells.

关键词： Digital signal processing Arithmetic Coprocessors Energy consumption Auditory system Speech Computer architecture Hardware Computational complexity Linear predictive coding

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Real-time signal preprocessor trade-off study

Real-time signal preprocessor trade-off study

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IEEE National conference on Aerospace and Electronics (NAECON)

作者： K.L. Hill L.C. Foti D.B. Zebe B.A. Box WL/AAAT-2 USA Lockheed Sanders Inc. USA Texas Instruments Inc. USA

signal preprocessing for avionics systems has typically consisted of custom hard-wired solutions which offer high performance but little design flexibility. Recently, a preprocessor trade-off study for an infrared (IR) application evaluated two advanced processing architectures both of which can provide not only high-performance, but also design flexibility. The objective of the study was to determine the best preprocessing solution for the Medium Wave IR Array (MIRA) system based on algorithm performance, processing density, "programmability", cost, and schedule. This study is based on the implementation of two IR algorithms each separately executed and evaluated on both of the architectures. The two architectures which were evaluated are the Lockheed Sanders Configurable-Hardware Algorithm-Mappable Preprocessor (CHAMP), developed under contract with the Wright Laboratory Avionics Directorate, and the Texas Instruments (TI) TMS320C80 Digital signal Processor. In the last decade, the hardware community has seen the introduction of the field programmable gate array (FPGA) which offers fast reconfigurability and high performance. The CHAMP preprocessor architecture, which is based on FPGA technology, was conceived to produce an alternative preprocessor that can provide high-performance, implementation flexibility, low cost, and a much reduced development cycle. CHAMP provides up to 4 BOPS on a double-sided 6U VME board. CHAMP technology is applicable to preprocessing for IR, forward looking IR (FLIR), imaging, including magnetic resonance imaging (MRI) and mammography, and automatic target recognition (ATR). Recent improvements in the DSP arena, particularly in packaging and performance, have made DSP architectures much more competitive. Texas Instruments (TI) has developed the Multimedia Video Processor (MVP) also known as the TMS320C80 Digital signal Processor. It is rated at 2 BOPS and is a fully programmable digital signal processor. The MVP architecture contains

关键词： signal processing algorithms Digital signal processors Field programmable gate arrays Magnetic resonance imaging Digital signal processing Aerospace electronics Costs Instruments signal design Scheduling algorithm

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On the convergence of traffic measurement and queueing analysis: a Statistical-MAtch Queueing (SMAQ) tool

On the convergence of traffic measurement and queueing analy...

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IEEE Annual Joint conference: INFOCOM, IEEE Computer and Communications Societies

作者： Chia-Lin Hwang San-qi Li Department of Electrical and Computer Engineering University of Technology Austin TX USA

ISBN: (纸本)081866990X

The analytical tool developed in this paper provides a general solution technique for the integration of traffic measurement and queueing analysis. The frequency-domain approach is used to combine the advanced techniques in two areas: signal processing and queueing analysis. Essentially, signal processing techniques are used to obtain the steady-state and second-order statistics of a traffic stream. The focus here is on the construction of a special class of Markov chains that can statistically match with each given traffic stream (or superposition of different traffic streams). The analytical queueing solutions can therefore be obtained by the folding-algorithm based on the Markov chain input modeling. Comprehensive numerical examples show the great potential of the SMAQ tool to solve measurement-based traffic management issues.

关键词： Queueing analysis Convergence Traffic control Higher order statistics signal processing algorithms Telecommunication traffic Steady-state Statistical distributions Frequency domain analysis Random processes

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Generalized interpolators for advanced movement-compensated 50 Hz-60 Hz conversion of interlaced sequences

Generalized interpolators for advanced movement-compensated ...

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IEEE International conference on Image processing

作者： L. Vandendorpe P. Delogne D. Boucquey Telecommunications and Remote Sensing Laboratory University College London Belgium

Several television standards exist for TV and for HDTV signals. The worldwide interchange of programs makes the conversion between them of critical importance. Conventional transcoders use a static interpolation filter which is not able to deal with incorrectly bandlimited television signals. Motion compensation has been introduced in order to adapt interpolation to the signal. This approach proposes movement-oriented filtering and has been shown to give significant improvement. However, the known algorithms do not offer a perfect reconstruction step when the desired pixels have to be interpolated. A new system is proposed for the conversion between the popular interlaced TV standards (625 lines, 50 fields/s or 525 lines, 60 fields/s). The key feature is the use of generalized interpolators that are based on nonuniform sampling theory. The performance is compared with alternative interpolation techniques. In addition, the attached motion estimation algorithm relies on segmentation in the target field (i.e. the unknown 60 Hz field) to avoid assignment problems.

关键词： Sampling methods TV Interpolation signal resolution Remote sensing Laboratories Telecommunication standards HDTV Filters Motion compensation

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A DSP-based position sensor elimination method with an on-line parameter identification scheme for permanent magnet synchronous motor drives

A DSP-based position sensor elimination method with an on-li...

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conference Record of the IEEE Industry Applications Society Annual Meeting (IAS)

作者： A.H. Wijenayake J.M. Bailey M. Naidu Advanced Architecture & Technology Allen-Bradley Company슠Inc. Milwaukee WI USA Department of Electrical & Com. Engineering University of Tennessee Knoxville TN USA Electrical & Electronics Department General Motors Research and Development Laboratories Warren MI USA

This paper presents a digital signal processor-based algorithm with an on-line parameter identification scheme for precision estimation of the rotor position and speed of a permanent magnet adjustable speed drive system by measuring stator currents, voltages and temperature. A modified d-q equivalent circuit model has been obtained to account for the core losses. Machine parameter variations due to saturation and temperature are included in the algorithm, which is valid for any speed, including zero speed. A simple hardware implementation to estimate the initial rotor position during the machine start-up and the implementation of position estimation algorithm, using a TMS320C25 DSP, is discussed. Because the estimation algorithm needs few instructions, it can easily be implemented in real-time vector control of permanent magnet synchronous drives. A complete vector-controlled drive system using an actively clamped resonant DC link inverter with the position estimator has been simulated, and results show that the estimated position is in close agreement with the actual rotor position of the machine.

关键词： signal processing algorithms Permanent magnets Magnetic sensors signal processing Parameter estimation Variable speed drives Current measurement Position measurement Velocity measurement Stator cores

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Time varying vector channel estimation for adaptive spatial equalization

Time varying vector channel estimation for adaptive spatial ...

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IEEE conference and Exhibition on Global Telecommunications (GLOBECOM)

作者： G.G. Raleigh A. Paulraj Information Systems Laboratory University of Stanford Stanford CA USA Advanced Wireless Research Group Watkins-Johnson Company Palo Alto CA USA Stanford University Stanford CA US Inf. Syst. Lab. Stanford Univ. CA USA

New blind adaptive spatial equalization techniques are proposed for severe multipath fading with co-channel interference. In rapidly fading environments, equalizer performance suffers with existing algorithms because the desired and interference channels change significantly over the update time interval. It is shown that for fast fading channels, conventional squared error equalizer cost functions can yield poor results. A new algorithm is proposed based on a variation of the SINR cost function coupled with optimal time varying channel estimation to improve signal tracking. In simulations, the algorithm achieves theoretically optimum time varying equalizer performance in extreme interference channels with narrow band FM signals and high velocity portables. These results are contrary to the widespread belief that high performance blind adaptive array processing is not possible for AMPS with severe combinations of Doppler spread, angle spread, and interference power.

关键词： Channel estimation Fading Interference channels Cost function Adaptive equalizers Blind equalizers Interchannel interference signal to noise ratio Narrowband Array signal processing

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Forecasting by density shaping using neural networks

Forecasting by density shaping using neural networks

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Proceedings of the IEEE/IAFE Computational Intelligence for Financial Engineering (CIFEr)

作者： Y. Baram Z. Roth Department of Computer Science Technion-Israel Institute of Technology Haifa Israel Ames Research Center NASA CA USA Advanced Technology Center Qualcomm Haifa Israel

An estimate of the probability density function of a random vector is obtained by maximizing the output entropy of a feedforward network of sigmoidal units with respect to the input weights. A normalized version of the sigmoidal transfer function simplifies the algorithm considerably and leads to a maximum entropy estimate of the input density under a certain model. Newton's method, applied to the estimated density, yields a recursive estimator for a random variable or a random sequence. A constrained connectivity structure yields a linear estimator, which is particularly suitable for "real time" prediction.

关键词： Neural networks Entropy Function approximation Recursive estimation Probability density function Transfer functions Yield estimation signal processing algorithms Feedforward systems Random variables

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advanced READ CHANNELS FOR MAGNETIC DISK DRIVES

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IEEE TRANSACTIONS ON MAGNETICS 1994年第6期30卷 3807-3812页

作者： HOWELL, TD ABBOTT, WL FISHER, KD Quantum Corporation Milpitas CA USA

advanced read channels which sample the read signal and process those samples using algorithms borrowed from the communications industry allow us to reach higher storage densities and faster data rates than ever before. In this paper we describe some of the design issues involved in using a PRML (partial-response, maximum-likelihood) channel in a disk drive employing thin-film heads, zoned-recording, and embedded servo sectors. We discuss the effect of high transition densities required far a PRML channel on the design of heads and media. Finally, we survey some additional: signal processing methods which might-lead to even higher performance in the future.

关键词： Disk drives Magnetic heads signal processing Maximum likelihood detection Servomechanisms Detectors Magnetic recording Decision feedback equalizers Transistors Intersymbol interference

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CONTRIBUTION OF THE POLARIZATION DIVERSITY IN HF DIRECTION FINDING SYSTEMS

CONTRIBUTION OF THE POLARIZATION DIVERSITY IN HF DIRECTION F...

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5th SPIE conference on advanced signal processing - algorithms, Architectures, and Implementations

作者： ERHEL, Y EDJEOU, A BERTEL, L CTR RECH ECOLES COETQUIDAN F-56381 GUERFRANCE

ISBN: (纸本)0819416207

The aim of the paper is to estimate the contribution of the polarization diversity in high frequency (3 - 30 MHz) direction finding systems. We first describe the peculiarities of H.F. propagation and the resulting signal model involved in computer simulations. Next, we analyze the behavior of some particular direction finding systems using linear and circular geometries and polarization diversity. Some algorithms (non linear frequential analysis, M.U.S.I.C.) are tested in several conditions (narrowband or broadband signals, polarization filtering reiterated or no, sub-sampling). Theoretical and experimental results show that polarization diversity based upon the knowledge of the antenna complex responses improves greatly the efficiency of direction finding.

关键词： DIRECTION FINDING POLARIZATION ARRAY processing HIGH RESOLUTION algorithms HF PROPAGATION

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SCALABLE PARALLEL IMPLEMENTATIONS OF PERCEPTUAL GROUPING ON CONNECTION MACHINE CM-5 12

SCALABLE PARALLEL IMPLEMENTATIONS OF PERCEPTUAL GROUPING ON ...

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conference C on signal processing and conference D on Parallel Computing, at the 12th IAPR International conference on Pattern Recognition

作者： PRASANNA, VK WANG, CL UNIV SO CALIF DEPT EE SYSTLOS ANGELESCA 90089

ISBN: (纸本)0818662751

Perceptual grouping is a key step in vision to organize image data into structural hypotheses to be used for high level analysis. In this paper, we propose data allocation and load balancing strategies which reduce the communication cost and evenly distribute the grouping operations among the processors. These techniques result in scalable algorithms for performing perceptual grouping on CM-5. The performance of our algorithms depends only on the total grouping operations generated by the image data and is independent of the distribution of the data among the processors. Our implementations show that given a 1K × 1K input image, extraction of line segments and several perceptual grouping steps can be performed in 5.0 seconds using a partition of CM-5 having 32 processing nodes. A serial implementation of these steps on a Sun Sparc 400 takes more than 2 minutes. © 1994 IEEE.

关键词： Parallel processing systems

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