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Theoretical assessment of a synthetic aperture beamformer for real-time 3-D imaging

IEEE TRANSACTIONS ON ULTRASONICS FERROELECTRICS AND FREQUENCY CONTROL 1999年第4期46卷 972-980页

作者： Hazard, CR Lockwood, GR Cleveland Clin Fdn Dept Biomed Engn Cleveland OH 44195 USA

A real-time 3-D imaging system requires the development of a beamformer that can generate many beams simultaneously, In this paper, we discuss and evaluate a suitable synthetic aperture beamformer. The proposed beamformer is based on a pipelined network of high speed digital signal processors (DSP). By using simple interpolation-based beamforming, only a few calculations per pixel are required for each channel, and an entire 2-D synthetic aperture image can be formed in the time of one. transmit event. The performance of tl lis beamformer was explored using a computer simulation of the radiation pattern. The simulations were done for a full 64-element array and a sparse array with the same receive aperture but only five transmit elements. Mio assessed the effects of changing the sampling rate and amplitude quantization by comparing the relative levels of secondary lobes in the radiation patterns. The results show that the proposed beamformer produces a radiation pattern equivalent, to a conventional beamformer using baseband demodulation, provided that the sampling rate is approximately 10 times the center frequency of the transducer (34% bandwidth pulse), The simulations also show that the sparse array is not significantly more sensitive to delay or amplitude quantization than the full array.

关键词： Brain modeling Sampling methods Quantization Real time systems Digital signal processors Digital signal processing Array signal processing Pixel Computer simulation Computational modeling

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Synthesis of DSP soft real-time multiprocessor systems-on-silicon

Synthesis of DSP soft real-time multiprocessor systems-on-si...

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IEEE International Conference on Acoustics, Speech, and signal processing (ICASSP 99)

作者： Kirovski, D Potkonjak, M Univ Calif Los Angeles Dept Comp Sci Los Angeles CA 90095 USA

ISBN: (纸本)0780350413

The recent convergence of applications (Internet and embedded applications) and technology (reuse and very high integration level) trends resulted in a strong need for design of soft real-time DSP systems on silicon. We developed a new hierarchical modular approach for synthesis of area efficient soft real-time DSP systems on silicon. This synthesis strategy employs a number of optimization intensive scheduling, performance monitoring, and allocation steps. The backbone of the optimization approach is a novel online scheduling algorithm which uses meta-algorithmic techniques for on-the-fly heuristic selection and parameter tuning. Resource allocation refers to a predetermined lower-bound system performance, to perform a branch-and-bound resource allocation search for an area-efficient multiprocessor configuration where each processor has local instruction and data cache. In order to bridge the gap between the profiling, modeling, and synthesis tools of the two traditionally independent synthesis domains (architecture and CAD), we develop a new synthesis and evaluation platform which integrates the existing modeling, profiling, and simulation tools with the new developed system-level synthesis tools. The effectiveness of the approach is demonstrated on the industrial strength MediaBench benchmark suite.

关键词： Silicon

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Imaging infrared seeker processing overview: image processing, adaptive thresholding, and track processing

Imaging infrared seeker processing overview: image processin...

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Proceedings of the 1999 Infrared Imaging systems: Design, Analysis, modeling and Testing X

作者： Kemper Jr., Paul J. Dimarco, John S. Georgia Tech Research Inst Atlanta GA United States

ISBN: (纸本)0819431753

processing images from an infrared imaging seeker for automatic target detection is an extremely complex issue. Many algorithms exist for image feature enhancement, adaptive thresholding, and track file processing. The authors present an overview of imaging signal processing algorithms, including image processing, image segmentation, and track processing with the intent of highlighting the interrelationship between algorithms and the necessity of evaluating seeker algorithms as a whole. The paper also discusses performance metrics for seeker-intercept geometries and the evaluation of metrics in a closed-loop aircraft-intercept simulation.

关键词： Infrared imaging

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Utilizing COTS software for the infrared scene generation process used in weapon system simulation

Utilizing COTS software for the infrared scene generation pr...

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Conference on Technologies for Synthetic Environments - Hardware-in-the-Loop Testing IV

作者： Ammon, J Raytheon Missile Syst Co Tucson AZ 85734 USA

ISBN: (纸本)0819431710

Raytheon Missile systems Company (RMSC) operates all digital and real-time Hardware-In-The-Loop (HWIL) simulations in support of infrared guided missile development. These simulations exercise the missile guidance algorithms with inputs reflective of an engagement scenario. When an air to air weapon system is activated it receives pointing cues from the launcher and the infrared (IR) seeker slaves to acquire the target image within its field of view. The images are processed by the tracker algorithms to locate salient features in the scene. The resulting target track provides a precise target-relative position update for missile guidance. The image generation portion of the simulation provides scenes appropriate for closed loop operation. Seeker location and orientation, target location and orientation, counter measure and background location are provided by a 6 Degree Of Freedom (6-DOF) simulation. These locations are input to a 3-D rendering program to generate a spatially correct 2-D image at the seeker's resolution. This must be done in the IR spectral band-pass of the seeker's sensor. image generation requires background capability if the simulation is to provide missile system performance evaluation. Radiometrically and spatially correct images must be provided to the seeker/tracker system. This paper details the methods used at Raytheon to generate these backgrounds for missile simulation. The paper exemplifies the process in which radiometric imagery is derived from aerial photography and is manipulated to produce scenes that are accurate for the diurnal cycle of a given area. A large portion of the task is processed up-front before simulation to produce the data bases needed for real-time rendering during a missile simulation. The process described utilizes Commercial Off The Shelf (COTS) software running on an SGI ONYX computer system. The techniques employed in achieving this scene generation capability should be applicable to many systems employing infra

关键词： Databases image processing Infrared imaging Missiles Sensors Atmospheric modeling Computer simulations Data modeling Weapons Electro optical modeling

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GLLS for optimally sampled continuous dynamic system modeling: theory and algorithm

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COMPUTER METHODS AND PROGRAMS IN BIOMEDICINE 1999年第1期59卷 31-43页

作者： Feng, D Ho, D Lau, KK Siu, WC Hong Kong Polytech Univ Dept Elect & Informat Engn Ctr Multimedia Digital Signal Proc Hong Kong Peoples R China Univ Sydney Dept Comp Sci Biomed & Multimedia Informat Technol Grp Sydney NSW 2006 Australia

The original generalized linear least squares (GLLS) algorithm was developed for non-uniformly sampled biomedical system parameter estimation using finely sampled instantaneous measurements (D. Feng, S.C. Huang, Z. Wang, D. Ho, An unbiased parametric imaging algorithm for non-uniformly sampled biomedical system parameter estimation, IEEE Trans. Med. Imag. 15 (1996) 512-518). This algorithm is particularly useful for image-wide generation of parametric images with positron emission tomography (PET), as it is computationally efficient and statistically reliable (D. Feng, D. Ho, Chen, K., L.C. Wu, J.K. Wang, R.S. Liu, S.H. Yeh, An evaluation of the algorithms for determining local cerebral metabolic rates of glucose using positron emission tomography dynamic data, IEEE Trans. Med. Imag. 14 (1995) 697-710). However, when dynamic PET image data are sampled according to the optimal image sampling schedule (OISS) to reduce memory and storage space (X. Li, D. Feng, K. Chen, Optimal image sampling schedule: A new effective way to reduce dynamic image storage space and functional image processing time, IEEE Trans. Med. Imag. 15 (1996) 710-718), only a few temporal image frames are recorded (e.g. only four images are recorded for the four parameter fluoro-deoxy-glucose (FDG) model). These image frames are recorded in terms of accumulated radio-activity counts and as a result, the direct application of GLLS is not reliable as instantaneous measurement samples can no longer be approximated by averaging of accumulated measurements over the sampling intervals. In this paper, we extend GLLS to OISS-GLLS which deals with the fewer accumulated measurement samples obtained from OISS dynamic systems. The theory and algorithm of this new technique are formulated and studied extensively. To investigate statistical reliability and computational efficiency of OISS-GLLS, a simulation study using dynamic PET data was performed. OISS-GLLS using 4-measurement samples was compared to the non-li

关键词： positron emission tomography optimal sampling parameter estimation

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A software simulation testbed for third generation CDMA wireless systems 33

A software simulation testbed for third generation CDMA wire...

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33rd Asilomar Conference on signals, systems, and Computers, ACSSC 1999

作者： Sundaramurthy, V. Cavallaro, J. Dept. of Electr. and Comput. Eng. Rice Univ. 6100 Main Street HoustonTX United States

ISBN: (纸本)0780357000

This paper describes a testbed which simulates a third generation code division multiple access (CDMA) wireless link. The designer of next generation wideband CDMA systems has the choice of a wide array of advanced signal processing algorithms and a variety of operating environments. The Rice testbed is a tool to evaluate these design options and trade-offs in different system scenarios. The backbone of this testbed is a wireless CDMA multiuser link built using Simulink and Matlab. An efficient method of system modeling is used to accelerate the simulations. The testbed also uses a method for rapid prototyping of algorithms and DSP-based simulation acceleration for the new algorithm complexity and performance evaluation. © 1999 IEEE.

关键词： Testbeds

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performance evaluation of motion estimation algorithms for digital signal processors

Performance evaluation of motion estimation algorithms for d...

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IEEE Workshop on signal processing systems (SIPS)

作者： S. Reader T. Meng Center for Integrated Systems University of Stanford Stanford CA USA

Current implementations of MPEG2 encoders are specially designed in order to perform a huge number of operations, most of which occur during motion estimation. Many fast algorithms have been proposed to reduce the processing power necessary. This paper examines the results achieved by several methods that show promise for reducing computation while sacrificing as little image quality as possible. Methods that achieve these goals are desirable for use in future encoders that will be implemented on generic digital signal processors (DSPs).

关键词： Motion estimation signal processing algorithms Digital signal processors Computational modeling image quality Video compression Video sequences Discrete cosine transforms Transform coding Encoding

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A software simulation testbed for third generation CDMA wireless systems

A software simulation testbed for third generation CDMA wire...

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Asilomar Conference on signals, systems & Computers

作者： V. Sundaramurthy J. Cavallaro Department of Electrical and Computer Engineering Rice University Houston TX USA

关键词： Software testing Multiaccess communication signal processing algorithms signal design Algorithm design and analysis Wideband System testing Spine modeling Acceleration

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Synthesis of DSP soft real-time multiprocessor systems-on-silicon

Synthesis of DSP soft real-time multiprocessor systems-on-si...

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

作者： D. Kirovski M. Potkonjak Computer Science Department University of California Los Angeles CA USA

The convergence of applications (Internet and embedded applications) and technology (reuse and very high integration level) trends resulted in a strong need for design of soft real-time DSP systems-on-silicon. We developed a new hierarchical modular approach for synthesis of area efficient soft real-time DSP systems-on-silicon. This synthesis strategy employs a number of optimization intensive scheduling, performance monitoring, and allocation steps. The backbone of the optimization approach is a novel online scheduling algorithm which uses meta-algorithmic techniques for on-the-fly heuristic selection and parameter tuning. Resource allocation refers to a predetermined lower-bound system performance, to perform a branch-and-bound resource allocation search for an area-efficient multiprocessor configuration where each processor has local instruction and data cache. In order to bridge the gap between the profiling, modeling, and synthesis tools of the two traditionally independent synthesis domains (architecture and CAD), we develop a new synthesis and evaluation platform which integrates the existing modeling, profiling, and simulation tools with the new developed system-level synthesis tools. The effectiveness of the approach is demonstrated on the industrial strength MediaBench benchmark suite.

关键词： Digital signal processing Real time systems Multiprocessing systems Resource management Internet Job shop scheduling Monitoring Spine Scheduling algorithm System performance

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A detailed analysis of MediaBench

A detailed analysis of MediaBench

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IEEE Workshop on signal processing systems (SIPS)

作者： B. Bishop T.P. Kelliher M.J. Irwin Department of Computer Science and Engineering Microsystems Design Laboratory University Park PA USA Department of Mathematics & Computer Science Goucher College Baltimore MD USA

In this paper, we present a detailed analysis of the MediaBench benchmark suite. MediaBench consists of a number of popular embedded applications for communications and multimedia. MediaBench performance characteristics were examined by running MediaBench under the SimpleScalar simulation environment. Characteristics such as instruction mix, branch prediction accuracy, cache hit rates, memory usage, and integer bit utilization were considered. This information can be of use in designing embedded systems targeted at multimedia applications.

关键词： Decoding image coding Cryptography Multimedia communication Computational modeling Computer science Embedded system Multimedia systems Speech analysis Transform coding

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