agenda

Signal Processing Seminar

Rob Remis

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Signal Processing Seminar

Jamal Amini

Jamal is going to present his recent research.

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Signal Processing Seminar

Millad Sardarabadi

Millad is going to present his recent research.

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Signal Processing Seminar

3D direction of arrival estimation of multiple audio sources with spherical microphone arrays

Despoina Pavlidi
University of Crete, Department of Computer Science, Heraklion, Crete, Greece

Abstract: Direction of arrival estimation plays a central role in numerous signal-processing applications, such as smart home automation, surveillance systems, etc. Until recently the research community was mainly interested in single-dimensional direction of arrival (DOA) estimation by deploying linear or planar microphone arrays. Nowadays the focus has turned also towards spherical microphone arrays, which enable the more accurate capturing of the acoustic wavefield, hence enabling two-dimensional DOA estimation, i.e., the azimuth and elevation of an active audio source. In this talk we will present our proposed methodologies for DOA estimation in the 3D space. Our first proposed method relies on energetic analysis. We estimate the sound intensity vector on selected time-frequency elements of the spectrum and post-process the estimates utilizing 2D histogram representations. We enhance our approach by applying beamforming around local intensity vector directions. We call our hybrid approach spatially constrained beamforming (SCB). Our second proposed method improves the performance of two grid-based approaches, namely the steered response power (SRP) and the multiple signal classification (MUSIC) algorithm, both formulated in the spherical harmonic domain. We propose to derive local DOA estimates from the power map for SRP and the pseudospectrum for MUSIC. From these local DOA estimates we form a 2D histogram that we process to derive the final multiple sources directions.


Signal Processing Seminar

Shahrzad Naghibzadeh

Shahrzad is going to present her recent research.

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Signal Processing Seminar

Pim van der Meulen

Pim is going to present his recent research.

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Signal Processing Seminar

Image domain gridding for radio astronomy

Bas van der Tol
ASTRON

Fast implementations of a "non-uniform FFT" operation

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MSc CE Thesis Presentation

An Accurate System-Level Device Aging Assessment and Mitigation Simulation Framework

Evelyn Rashmi Jeyachandra

As technology scaling enters the nanometer regime, device aging effects cause quality and reliability issues in CMOS Integrated Circuits (ICs), which in turn shorten its lifetime. Evaluating system aging through circuit simulations is very complex and time consuming. In this thesis, a framework is proposed, which allows for the evaluation of long-term aging effects of ICs and the corresponding measures to counteract premature failure. The focus of this work lies in the abstraction of low-level aging models to system-level models, in order to facilitate swift high-level simulation, without any knowledge of underlying circuit dynamics.

Two major aging mechanisms, namely Negative Bias Temperature Instability (NBTI) and Channel Hot Carrier (CHC) degradation are considered for analysis. System-level aging management is performed with the prototype of a System-on-Chip (SoC) including a Management Unit (MU), which counteracts aging by employing Dynamic Voltage Scaling (DVS), Dynamic Frequency Scaling (DFS), and Adaptive Body Biasing (ABB). The simulation platform prototype is based on System-C and a 65-nm technology library. This SoC simulation computes path delay using characterized models, which represent the aged behaviour of individual circuit elements. Results show that the obtained values are within 2% of circuitlevel simulation values.

Furthermore, the System-C implementation has a shorter execution time with an approximate speedup of 15 times over conventional circuit simulators (e.g. Cadence NCSim).

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Signal Processing Seminar

Bahareh Abdikivanani

Bahareh is going to present her recent research.

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Signal Processing Seminar

Jie Zhang

Jie is going to present his recent research.

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Signal Processing Seminar

Thomas Sherson

Thomas is going to present his recent research.

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