Implementation of FIR filters for fast multi-channel processing

Digital signal processors are ubiquitous in electronics, with applications ranging from sound processing to software-defined radio. Finite impulse response (FIR) filters are among the components that are used for the processing; the implementation is tailored to the user’s needs, whether they specifically need performance or configurability. Handling numerous channels in a single filter block can be achieved in hardware by running multiple filters in parallels, with a high space expense and controller overhead. This project proposes and discusses an implementation template for a pipeline that simultaneously processes a desired number of channels, while keeping coefficients configurability. The implementation we propose is economic in terms of area while meeting the theoretical timing requirements to process long filters

Hardware And Software For Reproducible Research In Audio Array Signal Processing

In our demo, we present two hardware platforms for prototyping audio array signal processing. Pyramic is a 48-channel microphone array fitted on an FPGA and Compact Six is a portable microphone array with six microphones, closer to the technical constraints of consumer electronics. A browser based interface was developed that allows the user to interact with the audio stream from the arrays in real time. The software component of this demo is a Python module with implementations of basic audio signal processing blocks and popular techniques like STFT, beamforming, and DoA. Both the hardware design files and the software are open source and freely shared. As part of a collaboration with IBM Research, their beamforming and imaging technologies will also be portrayed. The hardware will be demonstrated through an installation processing the microphone signals into light patterns on a circular LED array. The demo will be interactive and let visitors play with different algorithms for DoA (SRP, FRIDA [1], Bluebild) and beamforming (MVDR, Flexibeam [2]). The availability of an open platform with reference implementations encourages reproducible research and minimizes setup-time when testing and benchmarking new audio array signal processing algorithms. It can also serve as a useful educational tool, providing a means to work with real-life signals

Extension board for CycloneV : Multi microphone acquisition - Signal Analysis (Extending the Pyramic Array)

The Pyramic architecture is a flexible 48-microphone array mounted on a powerful FPGA-SoC system. It allows to do massively multi-channel audio processing in real-time. This project implements an extension to the original system. In the original system, audio output is not allowed from the hardware processor system of the SoC, thus we cannot perform simultaneous capture and output. We implemented this through the design of an audio output controller, as well as a library (libpyramicio) that drives the capture and output from the software part and makes it easy for application developers to create algorithms that run on the Pyramic array

Maximal Atomic irRedundant Sets: a Usage-based Dataflow Partitioning Algorithm

International audiencePrograms admitting a polyhedral representation can be transformed in many ways for locality and parallelism, notably loop tiling. Data flow analysis can then compute dependence relations between iterations and between tiles. When tiling is applied, certain iteration-wise dependences cross tile boundaries, creating the need for inter-tile data communication. Previous work computes it as the flow-in and flow-out sets of iteration tiles. In this paper, we propose a partitioning of the flow-out of a tile into the maximal sets of iterations that are entirely consumed and incur no redundant storage or transfer. The computation is described as an algorithm and performed on a selection of polyhedral programs. We then suggest possible applications of this decomposition in compression and memory allocation

Maximal Atomic irRedundant Sets: a Usage-based Dataflow Partitioning Algorithm

International audiencePrograms admitting a polyhedral representation can be transformed in many ways for locality and parallelism, notably loop tiling. Data flow analysis can then compute dependence relations between iterations and between tiles. When tiling is applied, certain iteration-wise dependences cross tile boundaries, creating the need for inter-tile data communication. Previous work computes it as the flow-in and flow-out sets of iteration tiles. In this paper, we propose a partitioning of the flow-out of a tile into the maximal sets of iterations that are entirely consumed and incur no redundant storage or transfer. The computation is described as an algorithm and performed on a selection of polyhedral programs. We then suggest possible applications of this decomposition in compression and memory allocation

Increasing FPGA Accelerators Memory Bandwidth with a Burst-Friendly Memory Layout

International audienc

Pyramic: Full Stack Open Microphone Array Architecture And Dataset

In this paper we introduce an open source and reproducible microphone array hardware design and an anechoic dataset recorded with this array. The Pyramic array has 48 microphones spread onto six identical modules connected to an FPGA-ARM combo. The arrangement of the six modules can be reconfigured to create a large number of geometries. We describe in detail the architecture of the array and make openly available all necessary hardware design files, VHDL code, and C libraries together with extensive documentation. This effectively enables replicability of part or all of the array.The curated dataset of anechoic measurements done using the Pyramic array comprises source locations with dense azimuth sampling at multiple heights, playing both test and speech signals. The manual calibration of source and microphone locations is assessed and improved upon using time-difference of arrival methods. The array response to each source location is also provided. Finally, the dataset is used to assess the performance of two well-known direction of arrival estimation algorithms on the Pyramic architecture

High-frequency internal wave motions at the ANTARES site in the deep western mediterranean

[EN] High-frequency internal wave motions of periods down to 20 min have been observed in a yearlong record from the deep Western Mediterranean, mainly in vertical currents. The observations were made using the ANTARES neutrino telescope infrastructure. One line of the telescope is instrumented with environmental monitoring devices, and in particular with an Acoustic Doppler Current Profiler that was used to measure currents around 2,200 m. Such high-frequency internal waves are commonly observed much closer to the sea surface where the vertical density stratification is more stable than in the deep sea. In this paper, they are supported by the relatively large stratification following newly formed dense water. During the severe winters of 2005 and 2006, deep dense-water formation occurred in the Ligurian subbasin. Its collapse and spread over the sea floor across the basin remained detectable for at least 3 years as deduced from the present yearlong current record, which is from 2008. The observed high-frequency internal waves match the occasional density stratification observed in ¡«1-m-thin layers using previous shipborne conductivity¿C temperature¿C depth measurements. Such layers and waves are relatively unusual in the deep Mediterranean, where commonly several hundreds-ofmeters- thick near-homogeneous layers dominate. Such thick near-homogeneous layers provide about a half-decade narrow internal wave band around the inertial frequency (f). In contrast, the presently observed vertical currents occasionally show a ¡°small-scale¡± internal wave band that is on average 1.5 decades wide, associated with thin-layer stratification. In spite of its relatively largewidth, this band still shows variance peaking near f rather than near the large-scale buoyancy frequency N (= 2.3 4.5f) and this variance is found to increase with increasing N.The CTD observations were made in the framework of "Gyroscop" and "Gyroscop-2" for which we acknowledge Claude Millot and the Netherlands Organisation for the Advancement of Scientific Research, NWO, and Centre National de la Recherche Scientifique, CNRS, for support (French-Dutch collaboration). The authors acknowledge the financial support of the funding agencies: Centre National de la Recherche Scientifique (CNRS), Commissariat a l'energie atomique et aux energies alternatives (CEA), Commission Europeenne (FEDER fund and Marie Curie Program), Region Alsace (contrat CPER), Region Provence-Alpes-Cote d'Azur, Departement du Var and Ville de La Seyne-sur-Mer, France; Bundesministerium fur Bildung und Forschung (BMBF), Germany; Istituto Nazionale di Fisica Nucleare (INFN), Italy; Stichting voor Fundamenteel Onderzoek der Materie (FOM) and NWO, the Netherlands; Council of the President of the Russian Federation for young scientists and leading scientific schools supporting grants, Russia; National Authority for Scientific Research (ANCS - UEFISCDI), Romania; Ministerio de Ciencia e Innovacion (MICINN), Prometeo of Generalitat Valenciana and MultiDark, Spain; Agence de l'Oriental and CNRST, Morocco. 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