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IEEE Radio and Wireless Symposium (RWS formerly RAWCON)

作者： Atsushi Yamaoka Keiichi Yamaguchi Ichiro Seto Corporate Research & Development Center TOSHIBA Corporation Kawasaki Kanagawa Japan

In recent mobile communication systems, impairments in analog circuits cannot be disregarded owing to the need to achieve high performance. Errors in analog circuits consist of a distortion of a power amplifier(PA), gain and phase imbalance in a quadrature modulator(QMOD) and a quadrature demodulator(QDEMOD), dc offset, frequency offset, and so on. Because of high accuracy of compensation, many techniques of error compensation by using digital signal processing have been studied recently. Digital predistorter(DPD), which can eliminate odd-order distortion caused by PA nonlinearity, is one of the compensation techniques. However, in the case that direct conversion architecture is used in a loop-back path, errors in a QMOD and a QDEMOD affect the performance of DPD. Previously, we proposed an error estimation technique for a QMOD and a QDEMDO by using a variable phase shifter and evaluated the performance through computer simulation. In this paper, we evaluate the performance through an experiment by image rejection ratio(IRR) and error vector magnitude(EVM) in the case that the output of a QMOD is directly connected to the input of a QDEMOD. The results show that IRR improvement after compensation is 10 dB at the output of the QMOD and EVM improvement after compensation is 10 dB at the output of the QMOD and 20 dB at the output of the QDEMOD.

关键词： Error analysis Demodulation Analog circuits Computer errors Mobile communication Phase distortion Power amplifiers Phase modulation Frequency Error compensation

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Aberration evaluation of alignment optics in lithographic tools by use of a step-height structure highly sensitive to the asymmetry of an optical image

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APPLIED OPTICS 2007年第17期46卷 3485-3492页

作者： Ina, Hideki Takeda, Mitsuo Univ Electrocommun Dept Informat & Commun Engn Lab Informat Photon & Wave Signal Proc Tokyo 1828585 Japan Canon Inc Nanotechnol & Syst Res Labs Utsunomiya Tochigi 3213292 Japan

To satisfy the increasing demand for extremely tight overlay accuracy in semiconductor manufacturing processes, all the measurement error factors in alignment systems and overlay measurement tools need be identified and eliminated. The principle of most alignment systems is based on image processing of target marks on the wafer under bright-field illumination. Although the phenomenon that the sensitivity to the alignment error varies with the step height (SH) of the mark has been known and used for evaluating the performance of the alignment optics, no investigation has been made into the origin and the physical mechanism of the phenomenon. We propose a simplified optical model that can account for the origin of the asymmetric image and clarify its relation to the SHs. The model is validated with simulation and experimental results. The improved performance of an alignment system using marks with optimally designed SHs is demonstrated. (C) 2007 Optical Society of America.

关键词： Computer simulation Fast Fourier transforms image processing Optical design software Optical testing Silicon on insulator

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Mesoscopic-level simulation of dynamics and interactions of biological molecules using Monte Carlo simulation

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Journal of VLSI signal processing systems for signal, image, and Video Technology 2007年第3期48卷 287-299页

作者： Yamaguchi, Yoshiki Maruyama, Tsutomu Yasunaga, Moritoshi Azuma, Ryuzo Konagaya, Akihiko Graduate School of Systems and Information Engineering University of Tsukuba 1-1-1 Tenoudai Tsukuba Ibaraki 305-8573 Japan RIKEN Genomic Sciences Center 1-7-22 Suehiro-cho Yokohama Kanagawa 230-0045 Japan Department of Mathematics and Computing Sciences Tokyo Institute of Technology 2-21-1 Ookayama Meguro Tokyo 152-8552 Japan

A mesoscopic-level method for clarifying living cell dynamics is described that uses Monte Carlo simulation of biological molecule interactions. The molecules are described as particles that take a random walk in 3-dimensional discrete space. Many kinds of molecules (including complex forms) are supported, so complex reactions with enzymes can be simulated. Also described is an field programmable gate array system with reconfigurable hardware that that will support complete modeling of an entire cell. Two-phase processing (migration and reaction) is used to simulate the complex reactions, so the method can be implemented in a limited amount of hardware. The migration and reaction circuits are deeply pipelined, resulting in high performance. Estimated performance is 30 times faster than with a 3.2-GHz Pentium 4 computer. This approach should make it possible to eventually simulate cell interactions involving one billion particles. © 2007 Springer Science + Business Media, LLC.

关键词： Biomolecules

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MDST: Multiprocessor DSP simulation Toolkit for Voice processing Applications

MDST: Multiprocessor DSP Simulation Toolkit for Voice Proces...

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15th IEEE International Symposium on modeling, Analysis and simulation of Computer and Telecommunication systems

作者： Sedaghati-Mokhtari, Naser Bojnordi, Mahdi Nazm Fakhraie, Sied Mehdi Univ Tehran Sch ECE Silicon Intelligence & VLSI Signal Proc Lab Tehran 14395515 Iran

ISBN: (纸本)9781424418534

In this paper, we propose a multiprocessor DSP simulation toolkit suitable for performance evaluation of data-parallel applications like voice processing. The proposed toolkit uses the benefits of multi-level parallelism and clustering. Different DSP clusters are considered for the multiprocessor DSP simulation engine in which the DSP processors are grouped to cooperate. Satisfying the communication requirements, two global and local communication engines (GCE and LCE) implement the real behavior of intra- and inter-cluster communications. Using efficient abstraction levels for interconnections reduces the simulation time significantly. Abstract communication modeling, cycle-accurate behavior, and mull-level controlling are the most important features of the proposed simulation platform. performance of the simulator is verified by standard single- and mull-channel voice processing applications such as ITU-T G.729a speech codec.

关键词： MDST Multiprocessor DSP simulation toolkit Voice processing applications

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Advances in simulation tools and their applications to CT, PET/CT and SPECT/CT

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MEDICAL PHYSICS 2007年第6期34卷 2646-2647页

作者： Tsui, B. M. W. Johns Hopkins Univ Baltimore MD USA

In CT, PET/CT and SPECT/CT imaging research, we are often involved in the design, development and evaluation of instrumentation, data acquisition methods, and image reconstruction and processing techniques. Ideally, clinical trials using patient images from actual imaging systems should be used in the evaluation studies. In practice, clinical trials are difficult to perform due to the difficulties and the high costs in acquiring ‘good quality’ clinical images and physicians' time to read them. Most importantly, there is a lack of known ‘truth’ in most clinical images. In the past, although computer simulation methods allowed generation of a large number of images with known ‘truth’, they suffered from the availability of computer generated phantoms that realistically model human anatomy and physiological functions and the ability to generate simulate data that accurately represent data acquired from actual medical imaging systems. We have developed a 4D computer generated phantom that are based on the Visible Human data and cardiac and respiratory gated MRI and CT data from normal human subjects. The non-uniform rational b-splines (NURB) computer graphics tools were used to allow accurate modeling of the shapes of 3D anatomical structures and generation of collections of phantoms that represent variations in anatomical structures and physiological functions found in different patient populations. Also, analytical and Monte Carlo simulation methods have been developed to provide data that accurately model the imaging system geometry, and photon interactions in the phantom and within the imaging system. Applications of the simulation tools to CT, PET/CT and SPECT/CT imaging research will be demonstrated with sample research projects. They demonstrate the potential utility of the simulation tools in a wide variety of applications in the research and development of instrumentation, image reconstruction and processing methods of different medical imaging modalities in th

关键词： Medical imaging Computed tomography signal generators Medical image reconstruction Computer simulation Single photon emission computed tomography Biomedical modeling Computer modeling Data acquisition Medical image quality

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A modular coprocessor architecture for embedded real-time image and video signal processing

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International Conference on Embedded Computer systems - Architectures, modeling and simulation

作者： Flatt, Holger Hesselbarth, Sebastian Fluegel, Sebastian Pirsch, Peter Leibniz Univ Hannover Inst Mikroelekt Syst Appelstr 4 D-30167 Hannover Germany

ISBN: (纸本)9783540736226

This paper presents a modular coprocessor architecture for embedded real-time image and video signal processing. Applications are separated into high-level and low-level algorithms and mapped onto a RISC and a coprocessor, respectively. The coprocessor comprises an optimized system bus, different application specific processing elements and I/O interfaces. For low volume production or prototyping, the architecture can be mapped onto FPGAs, which allows flexible extension or adaption of the architecture. Depending on the complexity of the coprocessor data paths, frequencies up to 150 MHz have been achieved on a Virtex II-Pro FPGA. Compared to a RISC processor, the performance gain for an SSD algorithm is more than factor 70.

关键词： Video signal processing

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Case study:: performance evaluation for communication strategies in distributed embedded systems

Case study:: Performance evaluation for communication strate...

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European simulation and Modelling Conference (ESM 2007)

作者： Berger, Falk Daene, Bernd Pacholik, Alexander Fengler, Wolfgang Tech Univ Ilmenau Dept Comp Architecture D-98684 Ilmenau Germany

ISBN: (纸本)9789077381366

To analyze common topologies of communication systems there are several probabilistic analysis strategies existing. Regarding the analysis of the influence of routing strategies probabilistic assumption is hard to validate. We used a discrete event simulation based analysis method to examine the influence of routing strategies within communication structures using a ring topology. By modeling the routing strategy in detail we are able to easily determine a realistic performance behavior under different load conditions.

关键词： signal processing computer networks discrete event simulation performance analysis queueing

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Mapping and performance evaluation for heterogeneous MP-SoCs via packing

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International Conference on Embedded Computer systems - Architectures, modeling and simulation

作者： Ristau, Bastian Fettweis, Gerhard Tech Univ Dresden Vodafone Chair Mobile Commun Syst D-01062 Dresden Germany

ISBN: (纸本)9783540736226

The computational demand of signal processing algorithms is rising continuously. Heterogeneous embedded multiprocessor systems-on-chips are one solution to tackle this demand. But to be able to take advantage of the benefits of these systems, new strategies are required how to map applications to such a system and how to evaluate the system's performance at a very early design stage. We will present a static, analytical, bottom-up methodology for temporal and spatial mapping of applications to MP-SoCs based on packing. Furthermore we will demonstrate how the result can be used for performance evaluation and system improvement without the need for simulations.

关键词： Embedded systems

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Rapid abstract control model for signal processing implementation

Rapid abstract control model for signal processing implement...

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IEEE Workshop on signal processing systems

作者： Gaddam, Kannan Chandrachoodan, Nitin Srinivasan, S. Indian Inst Technol Madras HCL Technol Ltd Madras 600036 Tamil Nadu India Indian Inst Technol Madras Tamil Nadu India

ISBN: (纸本)9781424412211

Evaluating different architectures is an important step in implementing signal processing algorithms in hardware. Often specific resource or memory requirements and performance can be estimated only through simulation. This can be difficult when detailed system descriptions are used. There is a need for quick simulation and estimation of performance. The Rapid Abstract Control (RAC) model is presented as an approach to solve this problem. Simple primitives are defined that can be used to construct models for simulation. The Single Scale Retinex (SSR) algorithm is used to demonstrate the effectiveness of the modeling approach.

关键词： architecture design automation data flow analysis image processing field programmable gate arrays

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PEPA Analysis of MAP Effects in Hierarchical Mobile IPv6

PEPA Analysis of MAP Effects in Hierarchical Mobile IPv6

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15th IEEE International Symposium on modeling, Analysis and simulation of Computer and Telecommunication systems

作者： Wang, Hao Laurenson, Dave Hillston, Jane Univ Edinburgh Sch Engn & Elect Joint Res Inst Signal & Image Proc Inst Digital Commun Edinburgh EH8 9YL Midlothian Scotland Univ Edinburgh Sch Informat Lab Fdn Comp Sci Edinburgh EH8 9YL Midlothian Scotland

ISBN: (纸本)9781424418534

To overcome the drawbacks of the Mobile IPv6 protocol on handling local mobility management, IETF proposed the HMIPv6 protocol which introduces an intermediate mobility anchor point (MAP) to hide the movement of a mobile node within a local area. However, the MAP forms a bottleneck in the network since all the traffic destined for its served nodes has to go through it Most research on HMIPv6 focuses on protocol optimisation, and performance analysis of HMIPv6 is usually simulation-based. In this paper, we employ a performance evaluation formalism named PEPA to investigate the performance tradeoffs of MAPS in HMIPv6. performance measures such as response time and MAP utilisation are presented.

关键词： Mobile telecommunication systems

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