# Giusi AlfanoPolitecnico di Torino | polito · DISAT - Department of Applied Science and Technology

Giusi Alfano

phd (Information Engineering)

## About

55

Publications

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847

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Introduction

Additional affiliations

November 2015 - May 2016

April 2013 - September 2015

April 2012 - March 2013

## Publications

Publications (55)

Due to their low complexity, Minimum Mean Squared Error (MMSE) and Zero-Forcing (ZF) emerge as two appealing MIMO receivers. Although they provide asymptotically the same achievable rate as the signal-to-noise ratio (SNR) grows large, a non-vanishing gap between the signal to interference and noise ratio (SINR) obtained through the two receivers ex...

We study a dual-hop multiple-input multiple-output (MIMO) relay network where the traffic source uses a relay node, selected among several possible ones, to serve multiple users. Considering that the nodes deployment can be described by Poisson Point Processes in a sector area, we derive the distribution of the signal-to-interference-plus-noise rat...

Linear precoding and post-processing schemes are ubiquitous in wireless multi-input-multi-output (MIMO) settings, due to their reduced complexity with respect to optimal strategies. Despite their popularity, the performance analysis of linear MIMO receivers is mostly not available in closed form, apart for the canonical (uncorrelated Rayleigh fadin...

A doubly spatially-correlated multi-cluster scattering Rayleigh MIMO channel with
rectangular
scattering cluster matrices (under the assumption that the minimum dimension of these matrices is equal to the number of transmit and receive antennas) is considered in this letter. The moment generating function (MGF) of the information rate is derived i...

We present an information-theoretic analysis of a point-to-point Multiple-Input-Multiple-Output (MIMO) link affected by Rayleigh fading and multiple scattering, under perfect channel state information at the receiver. Unlike previous work addressing this setting, we investigate the Random Coding Error Exponent, its associated cutoff rate and the Ex...

A one-sided spatially-correlated multi-cluster scattering Rayleigh MIMO channel is considered in this work and its outage probability is derived in an analytic form based on Meijer function determinants. First, the spatially-uncorrelated case is addressed and the Moment Generating Function (MGF) of the information rate is expressed in an analytic c...

We study the achievable rate in a MIMO, dual-hop, relay network where source and relay nodes may precode their input signals before transmission. Although an iterative expression for optimal precoders in this scenario is available in the literature, the corresponding achievable rate cannot be obtained analytically. We therefore propose approximate...

The help of relay devices is of paramount importance to overcome the impairments of channel randomness, especially in a rich scattering scenario with no line-of-sight communication path. Relaying strategies are gaining increasing attention due also to the eventual deployment of small-cells in future generations wireless networks, where short-range...

We investigate the outage probability of a dual-hop MIMO system where amplify-and-forward relay and beamforming are used. A practically important case where proportional fair scheduling is implemented to schedule users transmissions and co-channel interference exists is considered in the analysis. Specifically, taking into account Rayleigh fading a...

This paper considers the problem of coherent (in the sense that both amplitudes and relative phases of the polarimetric returns are used to construct the decision statistic) multipolarization synthetic aperture radar change detection starting from the availability of image pairs exhibiting possible power mismatches/miscalibrations. The principle of...

The information that can be transmitted through a wireless channel, with
multiple-antenna equipped transmitter and receiver, is crucially influenced by
the channel behavior as well as by the structure of the input signal. We
characterize in closed form the probability density function (pdf) of the
output of MIMO block-fading channels, for an arbitr...

The mutual information of a MIMO wireless channel, impaired by memoryless phase-noise, is characterized. Both a Line-of-Sight (LOS) MIMO link and a downlink channel with multiple-antenna base station (BS) are studied. For both cases, closed-form approximations of the mutual information in the low-SNR regime are derived. Next, leveraging the obtaine...

This work gives an overview of analytic tools for the design, analysis, and
modelling of communication systems which can be described by linear vector
channels such as y = Hx+z where the number of components in each vector is
large. Tools from probability theory, operator algebra, and statistical physics
are reviewed. The survey of analytical tools...

This paper provides a characterization of the output and of the transition probability density function (pdf) of a MIMO block-fading channel, paving the way to its information-theoretic analysis. The information density, whose average in ergodic conditions gives the mutual information conveyed over the channel, is needed to characterize the channel...

Resource allocation for energy efficiency optimization in multi-carrier interference networks with multiple receive antennas is tackled. First, a one-hop network is considered, and then, the results are extended to the case of a two-hop network in which amplify-and-forward relaying is employed to enable communication. A distributed algorithm which...

The information that can be conveyed through a wireless channel, with multiple-antenna equipped transmitter and receiver, crucially depends on the channel behavior as well as on the input structure. In this paper, we derive analytical results, concerning the probability density function (pdf) of the output of a single-user, multiple-antenna communi...

We analyze throughput-delay scaling laws of mobile ad-hoc networks under a content-centric traffic scenario, where users are mainly interested in retrieving contents cached by other nodes. We assume limited buffer size available at each node and Zipf-like content popularity. We consider nodes uniformly visiting the network area according to a rando...

We provide an analytical characterization of the probability density function (pdf) of the output of a single-user, multiple-antenna communication link, impaired by block-fading. The analysis is carried out under the assumption of product structure for the channel input, assuming Gaussian noise, and an imperfect estimation of the channel available...

In a multiple-input-multiple-output (MIMO) down-link channel, the impact of line-of-sight, out-of-cell interferers and of antenna correlation on the energy efficiency (EE) of the communication is discussed. With reference to a power budget model reflecting the power expenditure of a base station (BS) together with the power employed for training, w...

This study examines the error distribution of aggregated MPDUs in 802.11n networks and whether or not forward error correction like raptor coding at the link layer would be useful in these networks. Several experiments with Qualcomm 4×4 802.11n ...

The problem of non-cooperative resource allocation in multi-cell uplink OFDMA systems with multiple base station antennas is considered in this paper. Non-cooperative games for subcarrier allocation and transmit power control are considered, aiming at maximizing the users' energy efficiency, measured in bit/Joule and representing the number of erro...

We study the performance of systems for signal parameters estimation, which are based on the linear minimum mean square error (LMMSE) filtering. Such an estimation technique is widely used in practical scenarios, specifically wireless sensor networks and MIMO communications. We model the estimation system through sums and products of random matrice...

Wireless networks are fundamentally limited by the intensity of the received signals and the mutual interference caused by many concurrent transmissions. We consider large wireless ad hoc networks whose underlying node distribution is a Poisson cluster process. Under the assumption that multiple antennas are available at each node, we evaluate the...

Stochastic geometry proves to be a powerful tool for modeling dense wireless networks adopting random MAC protocols such as ALOHA and CSMA. The main strength of this methodology lies in its ability to account for the randomness in the nodes' location jointly with an accurate description at the physical layer, based on the SINR, that allows to consi...

The law of the time to transmit a packet from a node to its intended receiver, in a wireless network with randomly deployed, multiple-antennas equipped nodes, whose communication is impaired by fading and interference, is investigated. SINR-based coverage at the physical layer is assumed, and the useful signal strength is shaped through either coop...

A statistical model for Land Mobile Satellite (LMS) channels, where transmitters and receivers are equipped with multiple antennas, is introduced. Several spectral statistics are given, which allow the theoretical performance analysis of the newly proposed channel model from both a communication and an information-theoretic point of view. Specifica...

We consider static ad hoc wireless networks comprising significant inhomogeneities in the node spatial distribution over the area and analyze the scaling laws of their transport capacity as the number of nodes increases. In particular, we consider nodes placed according to a shot-noise Cox process (SNCP), which allows to model the clustering behavi...

Information-theoretic performance analysis of a MIMO communication over Land Mobile Satellite (LMS) channels, under ergodic and non-ergodic regimes, is performed. The capacity-achieving input covariance matrix, and the corresponding ergodic capacity, assuming perfect receive-side information but making different assumptions on the amount of channel...

In this paper we study the optimal placement and optimal number of active relay nodes through the traffic density in mobile sensor ad hoc networks. We consider a setting in which a set of mobile sensor sources is creating data and a set of mobile sensor destinations is receiving that data through multihop wireless paths. We make the assumption that...

We consider a wireless sensor network that is deployed over an area of interest for environmental monitoring. As often in
the practice, the sensor nodes are randomly distributed on the area and their measurements are noisy. Furthermore, the sensors
measure a multidimensional physical field (signal), with correlated spectrum, which can be approximat...

Recently, analytical methods for finding moments of random Vandermonde matrices with entries on the unit circle have been proposed in the literature. Vandermonde matrices play an important role in signal processing and wireless applications, among which the multiple-antenna channel modeling, precoding or sparse sampling theory. Recent investigation...

In this contribution, we propose a new technique for collaborative sensing based on the analysis of the normalized (by the trace) largest eigenvalues of the sample covariance matrix. Assuming that several base stations are cooperating and without the knowledge of the noise variance, the test is able to determine the presence of mobile users in a ne...

In this paper we study the optimal placement and optimal number of active relay nodes through the traffic density in mobile sensor ad-hoc networks. We consider a setting in which a set of mobile sensor sources is creating data and a set of mobile sensor destinations receiving that data. We make the assumption that the network is massively dense, i....

We analyze the capacity scaling laws of wireless ad hoc networks comprising significant inhomogeneities in the node spatial distribution over the network area. In particular, we consider nodes placed according to a shot-noise Cox process, which allows to model the clustering behavior usually recognized in large-scale systems. For this class of netw...

We study the performance of signal estimation and reconstruction systems, that exploit the linear minimum mean square error (LMMSE) technique. This model often occurs in signal processing and wireless communications; some examples are radar applications, MIMO communications, or sensor networks sampling a physical field. Our performance analysis imp...

A MIMO radar system is conveniently modeled via random matrices, and its optimal design strongly relies on spectral properties of the matrix exploited to build the model itself. We offer a way to model a High Resolution Radar (HRR) detection in the MIMO case, based on recent results on the asymptotic spectral analysis of random Vandermonde matrices...

A compact model for the evaluation of scaling laws in random wireless networks is proposed and studied. The model allows the information-theoretic characterization of both point-to-point as well as distributed communications. It is analyzed under several assumptions about spatial correlation and the utilized channel state information and transmissi...

Coordinating the reception and transmission of signals across spatially distributed base stations has been shown to improve sum-rate performance by mitigating the effects of intercell interference in Multiple-Input-Multiple-Output (MIMO) cellular networks. Relying on recent results on the freeness of certain non-Gaussian random matrices, we provide...

The distribution of the sum of non-negative random variables plays an essential role in the performance analysis of diversity schemes for wireless communications over fading channels. While for common fading models such as the Rayleigh, Rice, and Nakagami, the performance of diversity systems is well understood, a minor attention has been devoted t...

A statistical model for land mobile satellite (LMS) channels, where transmitters and receivers are equipped with multiple antennas, is introduced. In addition to the probability density function (pdf) of the channel matrix grammian, spectral statistics are given. They allow the theoretical performance analysis of the newly proposed channel model fr...

This paper characterizes the marginal probability density function of an unordered eigenvalue of finite-dimensional random matrices of particular interest in MIMO (multiple-input multiple-output) wireless communications. Specifically, a technique is presented for deriving the eigenvalue statistics in one-side correlated Rayleigh-faded channels and...

This work introduces an effective approach to derive the marginal density distribution of an unordered eigenvalue for finite-dimensional random matrices of Wishart and F type, based on which we give several examples of closed-form and series expressions for the Shannon and eta transforms of random matrices with nonzero mean and/or dependent entries...

We deal with the problem of polarimetric detection of compound-Gaussian clutter with unknown distributed targets in covariance matrix. Since no uniformly most powerful (UMP) detector exists for the problem at hand, we devise and assess two classes of suboptimum receivers. The former contains two detectors, designed according to the Wald and the gen...

The authors consider the problem of detecting range-distributed targets in the presence of structured disturbance modelled as an autoregressive Gaussian process with unknown parameters. The focus is on two different scenarios. The first assumes that all the data vectors from the cells under test share the same covariance matrix (homogeneous environ...

We present closed-form expressions for the marginal density distribution of the unordered eigenvalues of HFH* where F is an input covariance and H is a matrix representing a MIMO (multi-input multi-output) Rayleigh-faded channel with one-sided correlation at either end of the link, transmitter or receiver, with no constraints on the numbers of ante...

In this paper we deal with the problem of polarization diversity detection in compound-Gaussian clutter with unknown covariance matrix. To this end we assume that a set of secondary data, free of signal components and with the same covariance structure of the cell under test, is available. Due to the lack of a uniformly most powerful (UMP) detector...

In this paper we address polarimetric adaptive detection of targets embedded in compound-Gaussian clutter with unknown covariance matrix. To this end we assume that a set of secondary data, free of signal components and with the same covariance structure of the cell under test, is available. We resort to a design procedure based upon the generalize...

We address polarimetric adaptive detection of targets embedded in compound-Gaussian clutter with unknown covariance matrix. To this end we assume that a set of secondary data, free of signal components and with the same covariance structure of the cell under test, is available. We resort to a design procedure based upon the generalized likelihood r...

This paper presents an explicit expression for the marginal probability density distribution of the un-ordered eigenvalues of a noncentral Wishart ma-trix HH where H can represent a multiple-input multiple-output channel obeying the Ricean law. By integrating over this marginal density distribution, the corresponding ergodic mutual information is c...

## Projects

Project (1)

Statistical Physics of Advanced Multiuser Detection