Alessandro Guidotti | Università di Bologna (original) (raw)

Papers by Alessandro Guidotti

Sistemas y Telemática, 2011

ABSTRACT The ever increasing demand for multimedia wireless communication systems is a key featur... more ABSTRACT The ever increasing demand for multimedia wireless communication systems is a key feature of more advanced markets. The buzzwords of personal communications, meant to provide “access to anyone, anywhere, at anytime to the wanted service”, implies that radio spectrum demands are dramatically increasing in most developed markets. The last World Radiocommunication Conference (WRC-07) allocated on a co-primary basis the upper part of the UHF band to mobile services as from 2015 in Region 1, taking advantage of the Digital Dividend due to the higher spectrum efficiency of digital TV with respect to the analogue system. This will cause potentially harmful mutual interference between TV and mobile radio services, that needs to be carefully analysed. In this paper we present a study of the co-channel interference problem, proposing a methodology to take into account the mutual interference between a LTE mobile network and a DVB-T system and highlighting the different behaviour of the two radio links.

Lecture Notes of the Institute for Computer Sciences, Social Informatics and Telecommunications Engineering, 2015

The increasing demand of wider frequency bands in wireless communications has lead in the last ye... more The increasing demand of wider frequency bands in wireless communications has lead in the last years to the introduction of novel techniques allowing to exploit more efficiently the radio spectrum. In particular, spectrum sharing is considered one of the key technologies for future wireless systems. Cognitive radio is considered the most important technique for efficiently allowing the spectrum sharing among heterogeneous systems. If on one hand the cognitive radio techniques have been extensively assessed in terrestrial communications, they remain quite an unexplored area in Satellite Communications (SatComs). In this paper an Interference Estimation technique for SatComs aiming to reuse the spectrum resources primarily allocated to terrestrial communications is discussed. In particular, its assessment in a realistic scenario, where multiple impairments are considered, is discussed.

In order to guarantee the reliability of Global Navigation Satellite Systems (GNSS) against jammi... more In order to guarantee the reliability of Global Navigation Satellite Systems (GNSS) against jamming devices, aimed at obscuring the satellite signals, interference management techniques need to be designed. In this paper a novel receiver architecture for the characterization and cancellation of interference is proposed, based on the characteristics of jamming interference signals. Nowadays, GNSSs form a fundamental infrastructure for a plethora of applications: localization, navigation, and time-synchronization services exhibit an ever increasing relevance due to the extensive adoption of mobile technologies. In this context, a major threat consists in attacks aimed to interfering with these applications. In particular, such threats are often based on the disruption of GNSS infrastructures. In most of the cases, this is achieved by means of so-called personal privacy devices [1], [2], [3], i.e., jamming devices transmitting signals in the GNSS bands aimed at obscuring the satellite ...

In this paper the hidden node problem for cognitive radio systems is addressed in real environmen... more In this paper the hidden node problem for cognitive radio systems is addressed in real environments. The hidden node margin related to the implementation of spectrum sensing algorithms in autonomous operation, has been evaluated with two different methodologies: ray-tracing deterministic and statistical approaches. The hidden node margin simulation results are shown for different urban scenarios and as a function of the topological parameters (e.g. street width).

2011 International Conference on Electromagnetics in Advanced Applications, 2011

Spectrum demands are dramatically increasing in most developed markets, due to the soaring demand... more Spectrum demands are dramatically increasing in most developed markets, due to the soaring demand for mobile broadband access. Furthermore, the ability to cover larger areas with the same power levels and the need for providing broadband access to digital divide areas is currently one of the major issues in the field of wireless communications. To cope with market needs, and

2013 International Conference on Localization and GNSS (ICL-GNSS), 2013

ABSTRACT Interference is the major threat to integrity of navigation systems. In this paper, we p... more ABSTRACT Interference is the major threat to integrity of navigation systems. In this paper, we provide new approaches to localization and characterization operations of GNSS jamming signals in both cooperative and distributed architectures. As for localization, Differential Received Signal Strength (DRSS) and an Extended Kalman Filter (EKF) are exploited. With respect to characterization, two approaches are envisaged, both based on exploiting the Karhunen-Loe`ve Expansion (KLE). In the first, the nodes estimate and reconstruct the received jamming signal and share this data between themselves or with a Fusion Center (FC), which exploits KLE for data aggregation. In the second approach, signal estimation and reconstruction are performed at the FC, thus decreasing the nodes’ complexity. The performance of the localization and characterization algorithms are analyzed in terms of Mean Localization Error (MLE) and Mean Square Error (MSE), respectively. Simulation results show that the proposed algorithms provide good performance.

2012 IEEE International Conference on Communications (ICC), 2012

... Thus, by substituting (5) in (4), the ASEP can be re–written as shown in (6) on top of this p... more ... Thus, by substituting (5) in (4), the ASEP can be re–written as shown in (6) on top of this page, where T (·, ·) is given in (7) on top of this page. In particular, in (7): (a) = follows from [24, Eq. (6.631)] with 1F1 (·; ·; being the Kummer confluent hypergeometric function [23, Ch. ...

2012 IEEE International Conference on Communications (ICC), 2012

ABSTRACT Accurate modeling of network interference, deep understanding of its impact on the achie... more ABSTRACT Accurate modeling of network interference, deep understanding of its impact on the achievable performance, and development of efficient techniques to mitigate or exploit it are three important and fundamental research assets in current and next-generation cellular networks. In this context, Andrews, Baccelli, and Ganti [1] have recently introduced a new analytical approach to estimate coverage and rate of cellular networks subject to other-cell interference. In this paper, we move from the approach developed in [1], and propose an alternative analytical derivation to compute the rate of cellular networks. More specifically, by using stochastic geometry and Poisson point processes theory, we derive a simple and easy-to-compute expression of the rate, which can be used for arbitrary network and channel parameters, e.g., path-loss exponent, receiver noise, density of Base Stations (BSs), etc. Compared to [1], our framework has two main distinguishable features: i) the rate can be computed via a single numerical integral, rather than via a three-fold numerical integral; and ii) the formula is applicable to arbitrary fading distributions on the intended link, rather than being useful for Rayleigh fading only. Our analytical derivation is substantiated through extensive Monte Carlo simulations.

Proceedings of the 4th International Conference on Cognitive Radio and Advanced Spectrum Management - CogART '11, 2011

The radio resource shortage is one of the most important characteristic to take into account when... more The radio resource shortage is one of the most important characteristic to take into account when deploying modern wireless telecommunication systems. A novel communication paradigm named Cognitive Radio, has been introduced in the last years for better exploiting the limited available spectrum and the inefficiency in the spectrum usage. Its main aim is to allow the co-existence of different wireless systems on the same spectral resource by limiting the mutual interference. One of the main challenge is to extend the cognitive paradigm also to satellite networks by considering hybrid satellite and terrestrial scenarios. Aim of this paper is to evaluate the coexistence of terrestrial and satellite networks by considering a cognitive approach when radio resource sharing is employed. The paper deals with the presentation of a statistical interference model that aims at evaluating the mutual interference among the two systems.

Proceedings of the 9th International Conference on Cognitive Radio Oriented Wireless Networks, 2014

During the last years, spectrum scarcity has become one of the major issues for the development o... more During the last years, spectrum scarcity has become one of the major issues for the development of new communication systems. Cognitive Radio (CR) approaches have gained an ever increasing attention from system designers and operators, as they promise a more efficient utilization of the available spectral resources. In this context, while the application of CRs in terrestrial scenarios has been widely considered from both theoretical and practical viewpoints, their exploitation in satellite communications is still a rather unexplored area. In this paper, we address the definition of several satellite communications scenarios, where cognitive radio techniques promise to introduce significant benefits, and we discuss the major enablers and the associated challenges.

2013 IEEE Wireless Communications and Networking Conference (WCNC), 2013

ABSTRACT In this paper, we introduce a new framework to compute the Outage Probability Pout) and ... more ABSTRACT In this paper, we introduce a new framework to compute the Outage Probability Pout) and the Average Symbol Error Probability (ASEP) of dual-hop Amplify-and-Forward (AF) relaying in the presence of noise, fading, and network interference. The interfering nodes are assumed to be randomly distributed in the 2D Euclidean plane according to a homogeneous Poisson point process. Our framework provides an upper-bound closed-form expression of Pout and ASEP over Rayleigh fading channels, additive noise at the relay and at the destination, and network interference at the destination. Our analytical derivation is substantiated through extensive Monte Carlo simulations.

2011 IEEE 73rd Vehicular Technology Conference (VTC Spring), 2011

The ever increasing demand for multimedia wireless communication systems is a key feature of more... more The ever increasing demand for multimedia wireless communication systems is a key feature of more advanced markets. The buzzword of personal communications, meant to provide "access to anyone, anywhere, at anytime" to the wanted service, implies that spectrum demands are dramatically increasing in most developed markets. To cope with these needs, and in order to exploit the released spectrum resulting from the Digital Switchover, the last World Radiocommunication Conference (WRC-07) allocated on a co-primary basis the upper part of the UHF band to mobile services as from 2015. This will cause potentially harmful mutual interference between TV and mobile radio services, that needs to be carefully analyzed. In this paper we present a study of the co-channel interference problem, proposing a methodology to take into account the mutual interference between a LTE mobile network and a DVB-T system and highlighting the different behaviour of the two radio links.

2010 IEEE Global Telecommunications Conference GLOBECOM 2010, 2010

In this paper we present the concept of cognitive satellite terrestrial radios (CSTR) for hybrid ... more In this paper we present the concept of cognitive satellite terrestrial radios (CSTR) for hybrid satellite-terrestrial systems (HSTS). The cognitive radio (CR) technology is being motivated by the radio regulatory bodies for efficient utilization of the radio spectrum. The future satellite ground terminals therefore need to integrate and co-exist with the spectrally crowded terrestrial wireless systems and hence we propose the idea of CSTR. The key issues are addressed and the concepts of developing CR based satellite ground terminals in HSTS for dynamic spectrum access on the ground are presented. Furthermore, the concept of 3D-Spatial reuse of the spectrum is also presented using the CSTR considering low elevated satellite ground stations. Two particular HSTS applications to illustrate the CSTR concept, a) the hybrid satellite-UWB (ultra wideband) communication system for personal area networks (PAN) with short range on ground communications, and b) the hybrid satellite-WRAN (wireless regional area networks) for long range on ground communications are presented. In both the applications the satellite uplink and the terrestrial radios adopt the CR functionalities. The key enabling technologies and their integrated architecture for the CSTR are also presented.

The Newcom++ Vision Book, 2012

This section offers a view on trends currently characterizing the ICT world, with special focus o... more This section offers a view on trends currently characterizing the ICT world, with special focus on wireless technologies in line with the NEWCOM++ research objectives. To approach this complex task, the activities carried out withinWPI. 6 are considered as a reference. At first, an attempt to classify personal needs is provided in order to present the rationale towards which ICT trends and technologies are growing and evolving. Then, an overview of ICT trends is presented through an original metaphor of the current ICT picture and biological ...