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Scheduling block-cyclic array redistribution

IEEE TRANSACTIONS ON PARALLEL AND distributed SYSTEMS 1998年第2期9卷 192-205页

作者： Desprez, F Dongarra, J Petitet, A Randriamaro, C Robert, Y Ecole Normale Super Lyon LIP F-69364 Lyon 07 France Univ Tennessee Dept Comp Sci Knoxville TN 37996 USA Oak Ridge Natl Lab Math Sci Sect Oak Ridge TN 37831 USA

This article is devoted to the run-time redistribution of one-dimensional arrays that are distributed in a block-cyclic fashion over a processor grid. While previous studies have concentrated on efficiently generating the communication messages to be exchanged by the processors involved in the redistribution, we focus on the scheduling of those messages: how to organize the message exchanges into "structured" communication steps that minimize contention. We build upon results of Walker and Otto, who solved a particular instance of the problem, and we derive an optimal scheduling for the most general case, namely, moving from a CYCLIC (r) distribution on a P-processor grid to a CYCLIC (s) distribution on a Q-processor grid, for arbitrary values of the redistribution parameters P, Q, r, and s.

关键词： distributed arrays redistribution block-cyclic distribution scheduling MPI HPF

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Can GPGPU Programming Be Liberated from the Data-Parallel Bottleneck?

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COMPUTER 2012年第8期45卷 42-52页

作者： Gaster, Benedict R. Howes, Lee Advanced Micro Devices

Heterogeneous parallel primitives (HPP) addresses two major shortcomings in current GPGPU programming models: it supports full composability by defining abstractions and increases flexibility in execution by introduci... 详细信息

关键词： Graphics Processing Unit Programming Performance Evaluation Parellel Processing Indexes Hardware Multithreading Hardware Massively Threaded Computing Systems Heterogeneous Parallel Primitives Braided Parallelism Persistent Threading GPGPU Programming Data Parallel Execution distributed arrays

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Analysis of Element Failures in Active Incoherent Microwave Imaging arrays Using Noise Signals

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IEEE MICROWAVE AND WIRELESS COMPONENTS LETTERS 2019年第2期29卷 161-163页

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

An analysis of the effects of receiver element failures in active incoherent microwave imaging arrays is presented. Active incoherent microwave imaging is a new imaging method that uses transmission of noise signals combined with a sparse array using interferometric processing. In this method, the failure of individual receiver array elements results in gradual degradation of the image, rather than losses of pixels. This letter analyzes the image degradation in terms of the root-mean-square error (RMSE) of the image formed with randomly failed elements compared to the image formed with all elements. Measured data using a 5.85-GHz experimental imaging system show that RMSE below 10% can be maintained with failure rates extending up to 25%. Modeled image formation performance and the sidelobe level of the point spread function is shown to track well with the measured data for up to 50% element failures, indicating a robust method for predicting imaging performance.

关键词： distributed arrays distributed radar failure analysis interferometric imaging radar imaging

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Two-Dimensional Beam Pattern Synthesis for Phased arrays With Arbitrary Element Geometry via Magnitude Least Squares Optimization

IEEE JOURNAL OF MICROWAVES

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IEEE JOURNAL OF MICROWAVES 2022年第2期2卷 337-346页

作者： Kenney, Russell H. Salazar-Cerreno, Jorge L. Mcdaniel, Jay W. Univ Oklahoma Sch Elect & Comp Engn Norman OK 73019 USA Univ Oklahoma Adv Radar Res Ctr Norman OK 73019 USA

In this paper, an optimization procedure for synthesizing shaped beams with an arbitrary geometry phased array system with real-time capability is presented. The algorithm involves a combination of an arbitrary extension of the Woodward-Lawson synthesis procedure with the magnitude least-squares optimization method. This simple combination significantly reduces the optimization time, enabling real-time beam shaping in response to changing requirements on beam shape or evolving geometry in distributed arrays. The technique places no restrictions on element positioning in all three spatial dimensions and is demonstrated to accurately reproduce the desired beam shape in both angular dimensions. The algorithm is demonstrated for multiple beam cases with a large, randomly generated array in computational simulation. The applicability of the algorithm to practical phased array hardware is also demonstrated using full-wave electromagnetic simulations and measurements of a realized arbitrary phased array system using a near-field scanner in an anechoic chamber.

关键词： Phased arrays array pattern synthesis beam-forming conformal arrays distributed arrays magnitude least-squares optimization

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Calibration and Direction of Arrival Performance of Sonar arrays Composed of Multiple Sub-arrays

Calibration and Direction of Arrival Performance of Sonar Ar...

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Conference on OCEANS MTS/IEEE Charleston

作者： Ganti, Anil Duke Univ Elect & Comp Engn Durham NC 27708 USA

ISBN: (纸本)9781538648148

distributed sonar arrays are promising in achieving high resolution acoustic imaging. For such arrays, however, the array manifold must be estimated from observations using calibration sources. This paper investigates the performance bounds on jointly estimating the manifold parameters of a distributed array as well as the direction of arrival of an unknown target. Simulations use two calibration sources with known bearings and a single target with an unknown bearing. It is shown that for a system of two uniform linear arrays in channels with exponentially decaying spatial coherence, there are predictable optimal separations between the sub-arrays. Furthermore, the optimal separation is shown to be nearly invariant to source calibration and target parameters.

关键词： passive sonar distributed arrays array calibration sub-arrays Cramer-Rao bounds

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MMSE-BASED SOURCE EXTRACTION USING POSITION-BASED POSTERIOR PROBABILITIES

MMSE-BASED SOURCE EXTRACTION USING POSITION-BASED POSTERIOR ...

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

作者： Taseska, Maja Habets, Emanuel A. P. Int Audio Labs Erlangen D-91058 Erlangen Germany

ISBN: (纸本)9781479903566

A scenario with multiple talkers and additive background noise is considered, where some talkers are active simultaneously and the activity of the talkers changes with time. We propose an MMSE-based method to blindly extract any talker using bin-wise position estimates obtained from distributed microphone arrays. In order to distinguish between different talkers, the position estimates are clustered using the expectation maximization algorithm. The resulting posterior probabilities allow to estimate the PSD matrices of the talkers and compute an MMSE-optimal linear filter for extracting each talker. We evaluate the performance of the proposed method in terms of noise and interference reduction and distortion of the desired speech signal at the output of a multichannel Wiener filter.

关键词： speech separation PSD matrix estimation distributed arrays expectation maximization

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A Digital Interferometric Array with Active Noise Illumination for Millimeter-Wave Imaging at 13.7 fps

A Digital Interferometric Array with Active Noise Illuminati...

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IEEE/MTT-S International Microwave Symposium (IMS)

作者： Vakalis, Stavros Nanzer, Jeffrey A. Michigan State Univ Elect & Comp Engn E Lansing MI 48824 USA

ISBN: (纸本)9781728168159

We present millimeter-wave imagery at 13.7 frames-per-second (fps) using a digital 16-element interferometric antenna array operating at 37 GHz. The scene is illuminated incoherently using three low-cost noise transmitters, mimicking the properties of thermal radiation. The array is based on commercial components and 3D-printed horn antennas. The system architecture is presented, along with the signal processing algorithm, and real-time imaging results.

关键词： Millimeter-wave imaging computational imaging digital antenna arrays distributed arrays noise radar

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Efficient update of ghost regions using active messages

Efficient update of ghost regions using active messages

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19th International Conference on High Performance Computing (HiPC)

作者： Milthorpe, Josh Rendell, Alistair P. Australian Natl Univ Res Sch Comp Sci Canberra ACT Australia

ISBN: (纸本)9781467323703;9781467323727

The use of ghost regions is a common feature of many distributed grid applications. A ghost region holds local read-only copies of remotely-held boundary data which are exchanged and cached many times over the course of a computation. X10 is a modern parallel programming language intended to support productive development of distributed applications. X10 supports the "active message" paradigm, which combines data transfer and computation in one-sided communications. A central feature of X10 is the distributed array, which distributes array data across multiple places, providing standard read and write operations as well as powerful high-level operations. We used active messages to implement ghost region updates for X10 distributed arrays using two different update algorithms. Our implementation exploits multiple levels of parallelism and avoids global synchronization;it also supports split-phase ghost updates, which allows for overlapping computation and communication. We compare the performance of these algorithms on two platforms: an Intel x86-64 cluster over QDR InfiniBand, and a Blue Gene/P system, using both stand-alone benchmarks and an example computational chemistry application code. Our results suggest that on a dynamically threaded architecture, a ghost region update using only pairwise synchronization exhibits superior scaling to an update that uses global collective synchronization.

关键词： parallel programming models Partitioned Global Address Space (PGAS) X10 language active messages structured grids distributed arrays ghost regions lattice Boltzmann method Smooth Particle Mesh Ewald method

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A Modular, distributed and Scalable DOA Estimator for MIMO Systems

A Modular, Distributed and Scalable DOA Estimator for MIMO S...

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IEEE/MTT-S International Microwave Symposium (IMS)

作者： Assoa, Adou Sangbone Bhat, Ashwin Ryu, Sigang Raychowdhury, Arijit Georgia Inst Technol Atlanta GA 30332 USA

ISBN: (纸本)9798350375053;9798350375046

This paper proposes a hybrid model-based and data-driven approach for scalable DOA processors. A proxy spectrum computed from the sampled covariance matrix of the antenna array is fed to a Convolutional Neural Network (CNN) for DOA estimation. This input proxy being of fixed size makes the neural network input invariant of the array size, enabling it to handle multiple array sizes without requiring any modification of the neural network structure or model parameters. To reduce the computation of the covariance matrix and proxy spectrum, we employ a system of subarrays with Nearest-Neighbor communication. The solution was implemented on a Xilinx ZCU102 FPGA targeting 100 MHz frequency for 8 to 64-element arrays. We achieve a low latency of 650 mu s for an array of 64 antennas.

关键词： Direction-of-Arrival distributed arrays MIMO Neural Network

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Null Forming in distributed Transmit Array Patterns 6

Null Forming in Distributed Transmit Array Patterns

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IEEE Future Networks World Forum (FNWF)

作者： Lipski, Michael V. US Naval Res Lab Div Informat Technol Washington DC 20375 USA

ISBN: (纸本)9798350324587

Collaborative transmit beamforming using coherent distributed arrays is a method by which multiple wireless nodes synchronize their transmissions in order to synthesize a virtual antenna array. This technique gives directional transmit ability to disadvantaged nodes in a wireless network that have size, weight, and power (SWaP) constraints, which in turn would allow the network to communicate over longer ranges and with greater efficiency. The distributed array gain in arbitrary directions outside of the main beam is aperiodic and unpredictable for an aperiodic sparse array, which represents the configuration of a typical wireless sensor network (WSN) or mobile ad hoc network (MANET). In this paper, we examine a null forming approach for planar distributed arrays that uses global heuristic optimization to adjust the positions of nodes to minimize radiation in a specified direction while maintaining the main beam. Simulations are used to track null depth and width over several scenario iterations. We also examine how node localization uncertainty affects manufactured nulls.

关键词： distributed arrays collaborative beamforming coherent arrays mobile ad hoc networks optimization

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