Publications by Reza Parhizkar

Ad Hoc Microphone Array Calibration: Euclidean Distance Matrix Completion Algorithm and Theoretical Guarantees

Hervé Bourlard, Reza Parhizkar, Afsaneh Asaei, Mohammadjavad Taghizadeh, Philip Neil Garner

This paper addresses the problem of ad hoc microphone array calibration where only partial information about the distances between the microphones is available. We construct a matrix consisting of the pairwise distances and propose to estimate the missing ...

2015

Sequences with Minimal Time-Frequency Uncertainty

Martin Vetterli, Yann Barbotin, Reza Parhizkar

A central problem in signal processing and communications is to design signals that are compact both in time and frequency. Heisenberg's uncertainty principle states that a given function cannot be arbitrarily compact both in time and frequency, defining a ...

Elsevier2015

Euclidean Distance Matrices: Essential Theory, Algorithms and Applications

Martin Vetterli, Reza Parhizkar, Juri Ranieri, Ivan Dokmanic

Euclidean distance matrices (EDMs) are matrices of the squared distances between points. The definition is deceivingly simple; thanks to their many useful properties, they have found applications in psychometrics, crystallography, machine learning, wireles ...

2015

Indoor localization method and system

Martin Vetterli, Gilles Baechler, Reza Parhizkar

An indoor localization method for estimating the location of nodes (n1, n2), at least one node (n1) being connected to at least another node (n2) by at least two different channels (ch1, ch1′), comprising the following steps: measuring a distance between t ...

2015

Single-Channel Indoor Microphone Localization

Martin Vetterli, Reza Parhizkar, Ivan Dokmanic

We propose a novel method for single-channel microphone localization inside a known room. Unlike other approaches, we take advantage of the room reverberation, which enables us to use only a single fixed loudspeaker to localize the microphone. Our method u ...

IEEE2014

Calibration Using Matrix Completion with Application to Ultrasound Tomography

Martin Vetterli, Amin Karbasi, Reza Parhizkar

We study the calibration process in circular ultrasound tomography devices where the sensor positions deviate from the circumference of a perfect circle. This problem arises in a variety of applications in signal processing ranging from breast imaging to s ...

Institute of Electrical and Electronics Engineers2013

Sequences with Minimal Time-Frequency Spreads

Martin Vetterli, Yann Barbotin, Reza Parhizkar

For a given time or frequency spread, one can always find continuous- time signals, which achieve the Heisenberg uncertainty principle bound. This is known, however, not to be the case for discrete-time sequences; only widely spread sequences asymptoticall ...

Ieee2013

Euclidean Distance Matrices : Properties, Algorithms and Applications

Reza Parhizkar

Euclidean distance matrices (EDMs) are central players in many diverse fields including psychometrics, NMR spectroscopy, machine learning and sensor networks. However, they are not often exploited in signal processing. In this thesis, we analyze attributes ...

EPFL2013

Acoustic Echoes Reveal Room Shape

Martin Vetterli, Reza Parhizkar, Yue Lu, Andreas Walther, Ivan Dokmanic

Imagine that you are blindfolded inside an unknown room. You snap your fingers and listen to the room’s response. Can you hear the shape of the room? Some people can do it naturally, but can we design computer algorithms that hear rooms? We show how to com ...

National Academy of Sciences2013

Calibration in Circular Ultrasound Tomography Devices

Martin Vetterli, Amin Karbasi, Reza Parhizkar

We consider the position calibration problem in circular tomography devices, where sensors deviate from a perfect circle. We introduce a new method of calibration based on the time-of-flight measurements between sensors when the enclosed medium is homogene ...

Ieee Service Center, 445 Hoes Lane, Po Box 1331, Piscataway, Nj 08855-1331 Usa2011

Sound Speed Estimation Using Wave-based Ultrasound Tomography: Theory and GPU Implementation

Martin Vetterli, Olivier Roy, Ivana Jovanovic, Ali Hormati, Reza Parhizkar

We present preliminary results obtained using a time domain wave-based reconstruction algorithm for an ultrasound transmission tomography scanner with a circular geometry. While a comprehensive description of this type of algorithm has already been given e ...

Spie-Int Soc Optical Engineering, Po Box 10, Bellingham, Wa 98227-0010 Usa2010