ISL Highlighted Publications

On the Distribution of Indefinite Quadratic Forms in Gaussian Random Variables

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T. Y. Al-Naffouri and M. Moinuddin and N. Ajeeb and B. Hassibi and A. L. Moustakas, "On the Distribution of Indefinite Quadratic Forms in Gaussian Random Variables", IEEE Transactions on Communications. vol. 64 , pp. 153-165, Jan 2016. Abstract: In this work, we propose a unified approach to evaluating the CDF and PDF of indefinite quadratic forms in Gaussian random variables. Such a quantity appears in many applications in communications, signal processing, information theory, and adaptive filtering. For example, this quantity appears in the mean-square-error (MSE) analysis of the normalized

Compressive Sensing for Millimeter Wave Antenna Array Diagnosis

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M. E. Eltayeb, T. Y. Al-Naffouri and R. W. Heath, "Compressive Sensing for Millimeter Wave Antenna Array Diagnosis", IEEE Transactions on Communications. pp. 1-Jan, Jan 2018. Abstract: The radiation pattern of an antenna array depends on the excitation weights and the geometry of the array. Due to wind and atmospheric conditions, outdoor millimeter wave antenna elements are subject to full or partial blockages from a plethora of particles like dirt, salt, ice, and water droplets. Handheld devices are also subject to blockages from random finger placement and/or finger prints. These blockages

Impulse Noise Estimation and Removal for OFDM Systems",  IEEE Transactions on Communications

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T. Y. Al-Naffouri and A. A. Quadeer and G. Caire, "Impulse Noise Estimation and Removal for OFDM Systems", IEEE Transactions on Communications. vol. 62 , pp. 976-989, Mar 2014 Abstract: Orthogonal Frequency Division Multiplexing (OFDM) is a modulation scheme that is widely used in wired and wireless communication systems. While OFDM is ideally suited to deal with frequency selective channels and AWGN, its performance may be dramatically impacted by the presence of impulse noise. In fact, very strong noise impulses in the time domain might result in the erasure of whole OFDM blocks of symbols

Energy Conservation in Adaptive Filtering

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A. H. Sayed, Tareq Y. Al-Naffouri, and Vitor H. Nascimento, "Energy conservation in adaptive filtering", Nonlinear Signal and Image processing: Theory, Methods, and Applications, CRC Press, November 2003. Introduction: The study of the steady-state and transient performance of adaptive filters is a challenging task because of the nonlinear and stochastic nature of their update equations (e.g., References 1 to 4). The purpose of this chapter is to provide an overview of an energy-conservation approach to study the performance of adaptive filters in a unified manner.4 The approach is based on

Mobility-Aware User Association in Uplink Cellular Networks

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R. Arshad and H. Elsawy and S. Sorour and M. S. Alouini and T. Y. Al-Naffouri, "Mobility-Aware User Association in Uplink Cellular Networks", IEEE Communications Letters. vol. 21 , pp. 2452-2455, Nov 2017. Abstract: This letter studies the mobility aware user-to-base station (BS) association policies, within a stochastic geometry framework, in two-tier uplink cellular networks with fractional channel inversion power control. Particularly, we model the BSs’ locations using the widely accepted Poisson point process and obtain the coverage probability and handover cost expressions for the coupled

SNR Estimation in Linear Systems With Gaussian Matrices

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M. A. Suliman and A. M. Alrashdi and T. Ballal and T. Y. Al-Naffouri, "SNR Estimation in Linear Systems With Gaussian Matrices", IEEE Signal Processing Letters. vol. 24 , pp. 1867-1871, Dec 2017. Abstract: This letter proposes a highly accurate algorithm to estimate the signal-to-noise ratio (SNR) for a linear system from a single realization of the received signal. We assume that the linear system has a Gaussian matrix with one sided left correlation. The unknown entries of the signal and the noise are assumed to be independent and identically distributed with zero mean and can be drawn from

Transient analysis of data-normalized adaptive filters

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T. Y. Al-Naffouri and A. H. Sayed, "Transient analysis of data-normalized adaptive filters", IEEE Transactions on Signal Processing. vol. 51 , pp. 639-652, Mar 2003. Abstract: This paper develops an approach to the transient analysis of adaptive filters with data normalization. Among other results, the derivation characterizes the transient behavior of such filters in terms of a linear time-invariant state-space model. The stability, of the model then translates into the mean-square stability of the adaptive filters. Likewise, the steady-state operation of the model provides information about