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1st Annual International Conference on Sensor Networks and Signal Processing (SNSP)

作者： Lu, Sheng Tao, Jianbo Wang, Wennai Nanjing Univ Posts & Telecommun Sch Commun & Informat Engn Nanjing 210003 Peoples R China

ISBN: (纸本)9781538674130

In this paper, we provide a solution to achieve the robustness of geometric calibration of distributed microphone arrays, under the condition that each microphone array has a non-ideal knowledge of the position of the microphones. We consider two microphone arrays located in arbitrary positions and propose a robust algorithm for sound source mapping based on cross-correlation function by placing a sound source in N different positions in the visual range of the two microphone arrays. An estimation is provided also on the rotation matrix R and translation vector t, which can represent the position and direction between two microphone arrays, using the techniques of Computer Vision. Experimental results demonstrate that the calibration algorithm based on cross-correlation function still performs well even in presence of a high microphone position error.

关键词： microphone array geometric calibration distributed array cross-correlation

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Joint Measurement of Target Angle and Angular Velocity Using Interferometric Radar with FM Waveforms

Joint Measurement of Target Angle and Angular Velocity Using...

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IEEE Radar Conference (RadarConf)

作者： Merlo, Jason Nanzer, Jeffrey A. Michigan State Univ Dept Elect & Comp Engn E Lansing MI 48824 USA

ISBN: (纸本)9781728189420

An architecture for a direct-downconversion complex correlation interferometric radar capable of the direct, joint measurement of angle and angular velocity of a point-target is presented. Due to the simplicity of the system, this technique can be implemented on existing radars with distributed receivers and a transmitter capable of frequency modulation. Derivations for the interferometric measurement of angle and angular velocity and guidelines for the design of such a system are presented. Simulations are provided for the proposed system with varying pulse-width, antenna baseline, and pulse center frequency. The results for all simulations show a low root-mean-square error which demonstrates the feasibility of the proposed system.

关键词： Correlation Interferometry Angle Estimation Angular Velocity Estimation distributed array distributed Radar

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Versioning Architectures for Local and Global Memory 21

Versioning Architectures for Local and Global Memory

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21st IEEE International Conference on Parallel and distributed Systems ICPADS

作者： Fujita, Hajime Iskra, Kamil Balaji, Pavan Chien, Andrew A. Intel Corp Santa Clara CA 95051 USA Univ Chicago Chicago IL 60637 USA Argonne Natl Lab Argonne IL 60439 USA

ISBN: (纸本)9780769557854

Future supercomputer systems will face serious reliability challenges. Among failure scenarios, latent errors are some of the most serious and concerning. Preserving multiple versions of critical data is a promising approach to deal with such errors. We are developing the Global View Resilience (GVR) library, with multi-version global arrays as one of the key features. This paper presents three array versioning architectures: flat array, flat array with change tracking, and log-structured array. We use a synthetic workload that mimics the memory access patterns of radix sort, N-body simulation, and matrix multiplication, comparing the three array architectures in terms of runtime performance, memory requirements, and version restoration costs. The experiments show that the flat array with change tracking is the best architecture in terms of runtime performance, for versioning frequencies of 10 (5) ops (1) or higher matching the second best architecture or beating it by up to 23 times, whereas the log-structured array is preferable for low memory usage, since it saves up to 98% of memory compared with a flat array.

关键词： Global View Resilience multi-versioning distributed array change tracking log-based data structures

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CRAMER-RAO BOUND ANALYSIS OF distributed DOA ESTIMATION EXPLOITING MIXED-PRECISION COVARIANCE MATRIX 47

CRAMER-RAO BOUND ANALYSIS OF DISTRIBUTED DOA ESTIMATION EXPL...

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47th IEEE International Conference on Acoustics, Speech and Signal Processing (ICASSP)

作者： Chowdhury, Md Waqeeb T. S. Zhang, Yimin D. Temple Univ Dept Elect & Comp Engn Philadelphia PA 19122 USA

ISBN: (纸本)9781665405409

In this paper, we analyze the Cramer-Rao bound of the distributed direction-of-arrival (DOA) estimation problem where the covariance matrix is formulated in a mixed-precision manner. In this scheme, the self-covariance matrix of a subarray is locally computed using the full-precision data received at the subarray, whereas one-bit data are exploited at the fusion center to compute the cross-covariance matrices between different subarrays. As such, the resulting covariance matrix of the distributed array consists of full-precision subarray self-covariance matrices and low-precision cross-covariance matrices between subarrays, thus termed as a mixed-precision covariance matrix. Such distributed DOA estimation scheme offers substantial reduction of the network communication overhead while maintaining the degrees of freedom offered by the distributed array. We provide the Cramer-Rao bound analysis which enables us to understand the importance of the self- and cross-covariance matrices and optimize the array parameters. The CRB analysis results are compared with the root mean-square error performance of the estimated signal DOAs.

关键词： Direction-of-arrival estimation Cramer-Rao bound mixed-precision covariance matrix one-bit quantization distributed array

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distributed interference cancellation for dynamic spectrum sharing

Distributed interference cancellation for dynamic spectrum s...

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IEEE International Conference on Communications (ICC 2008)

作者： Nishimori, Kentaro Yomo, Hiroyuki Popovski, Petar Takatori, Yasushi Prasad, Ramjee Kubota, Shuji NTT Corp NTT Network Innovat Labs 1-1 Hikari No Oka Yokosuka Kanagawa 2390847 Japan Aalborg Univ Dept Elect Syst DN-9220 Aalborg Denmark

ISBN: (纸本)9781424420742

This paper proposes a novel interference cancellation technique using the concept of a distributed array, for the secondary use of the frequency resources in frequency division duplexing (FDD) based cellular systems. In order to achieve efficient distributed interference cancellation, the secondary system exploit intervals for periodic training signals transmitted by FDD-time division multiple access (TDMA) based cellular systems. We show that an efficient interference cancellation can be achieved by introducing helpers that decode the interference and transfer it to the secondary nodes. We take advantage of the high-speed links within the secondary system and devise a data compressing scheme that reduces time for transferring the decoded interference. We clarify the effectiveness of the proposed scheme by using computer simulation. As a parameter, the transmission quality between the helper and secondary nodes is varied. The results indicate that the proposed distributed interference cancellation is effective compared to a conventional adaptive array using a zero forcing algorithm, when the signal to noise ratio between the helper and the target secondary node is greater than 20 dB.

关键词： secondary spectrum usage periodic tracing signal FDD systems distributed array interference information transfer

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Design and Qualitative/Quantitative Analysis of Multi-Agent Spatial Simulation Library

Design and Qualitative/Quantitative Analysis of Multi-Agent ...

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作者： Chuang, Timothy University of Washington

学位级别：Master's

Integrating sensor networks in cloud computing gives new opportunities of using as many cloud-computing nodes as necessary to analyze real-time sensor data on the fly. However, most cloud services for parallelization such as OpenMP, MPI, and MapReduce are not always suitable for on-the-fly sensor-data analyses that are implemented as model-based, entity-based, and multi-agent simulations. To address this semantic gap between analyzing algorithms and their actual implementations, we have designed and implemented MASS: a library for multi-agent spatial simulation that composes of a user application of distributed array elements and multi-agents, each representing an individual simulation place or an active entity. All computation is enclosed in each of elements and agents that are automatically distributed over different computing nodes. Their communication is then scheduled as periodic data exchanges among those entities using their logical indices. This thesis presents the design, implementation and evaluation of the MASS library.

关键词： distributed array Multi-Agent Multi-Process Multi-Threaded Parallel Computing Spatial Data Analysis Computer science

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Effects of local oscillator errors on digital beamforming

Effects of local oscillator errors on digital beamforming

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作者： Marcos Chi Lim Siu US Naval Postgraduate School

学位级别：硕士

Digital phased array antennas are sensitive to phase error among elements because it affects the coherence necessary to create the array factor. There are many sources for phase errors: local oscillators and clocks, quadrature modulators and demodulators, non-linear components, and so forth. Additionally, phased arrays are sensitive to element mislocation, which introduces another source of phase error. In this research, three types of phase errors were studied: phase noise, gain unbalance in quadrature modulators and demodulators, and element mislocation. Modifications to the traditional array pattern expression were proposed to account for these errors, and equations were programmed in MATLAB to perform parametric simulations to generate information regarding gain loss, beam pointing error, pattern distortions, and degradation in sidelobe levels. The objective is to aid array designers in setting acceptable tolerance limits for these types of errors.

关键词： radar distributed array phased array phase synchronization digital array digital beamforming (dbf) wireless sensor network transmit/receive (t/r) module local oscillator phase noise

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A distributed subarray position optimization method based on DE-MIFT algorithm

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DIGITAL SIGNAL PROCESSING 2023年 143卷

作者： Qi, Keyan Jiang, Chaoshu Lin, Jie Deng, Xiaobo Hu, Qinzhen Chen, Fengfeng Univ Elect Sci & Technol China Sch Informat & Commun Engn Chengdu 611731 Sichuan Peoples R China Xihua Univ Sch Aeronaut & Astronaut Chengdu 610039 Sichuan Peoples R China Xihua Univ Engn Res Ctr Intelligent Air Ground Integrat Vehic Minist Educ Chengdu 610039 Sichuan Peoples R China China Leihua Elect Technol Res Inst Wuxi 214063 Jiangsu Peoples R China

distributed array radar is a next generation radar that has been a hot research direction due to its high maneuverability, low cost, and high reliability. However, the synthesized beam pattern of the distributed array usually has some high sidelobes and grating lobes, which reduce the system performance. In this paper, a hybrid algorithm based on the differential evolution algorithm and modified iterative Fourier transform algorithm called DE-MIFT is proposed for optimizing subarray positions in a distributed array model. This distributed array model is based on a uniform linear subarray with equal amplitude excitation. Moreover, an integer coding method based on the minimum spacing between subarrays is adopted in the proposed algorithm to encode and initialize population, then the two algorithms are used to optimize in parallel. Then a variable selection factor is used to select dominant individuals from the parallel optimization results, and the subarray position design of distributed array is obtained through iterations. It is shown by simulation results that the proposed algorithm can effectively suppress system grating lobes, reduce sidelobe levels, and has powerful global search capability and fast convergence speed.

关键词： distributed array Subarray position optimization Sidelobe and grating lobe suppression Improved iterative Fourier algorithm Differential evolution algorithm

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Experimental System and Results for distributed VHF Radar

Experimental System and Results for Distributed VHF Radar

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CIE International Conference on Radar (RADAR)

作者： Yang, Minglei Wang, Jing Chen, Baixiao Wang, Yi Xidian Univ Natl Lab Radar Signal Proc Xian Peoples R China

ISBN: (纸本)9781509048281

To solve the shortcomings of the Very High Frequency (VHF) radar, such as wide beam-width, low angular resolution and weak transportability, we propose a novel distributed VHF radar which consists of two identical VHF digital array radars. The system scheme of the experimental system and the main functions of the subsystems are given in this paper. We also design the signal processing method for the real data of the distributed VHF radar. The results of the real data show that the beam width of the distributed array is much narrower than that of the sub-arrays. And the accuracy of the angle estimation is around 1/10 that of the sub-arrays. Therefore, the proposed system can reach a high angle estimation accuracy with a relatively low cost and high transportability.

关键词： distributed array distributed aperture coherence-synthesizing radar Digital array module Experimental system Angle estimation

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PATH UNCERTAINTY ROBUST BEAMFORMING

PATH UNCERTAINTY ROBUST BEAMFORMING

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European Signal Processing Conference

作者： Richard Stanton Mike Brookes Imperial College London

ISBN: (纸本)9781479946037

Conventional beamformer design assumes that the phase differences between the received sensor signals are a deterministic function of the array and source geometry. In fact however, these phase differences are subject to random variations arising both from source and sensor position uncertainties and from fluctuations in sound velocity. We present a framework for modelling these uncertainties and show that improved beamformers are obtained when they are taken into account.

关键词： Robust beamforming distributed array SNR beamformer Steering vector mismatch

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