Giovanni Emanuele Corazza

Average Rate of Downlink Heterogeneous Cellular Networks over Generalized Fading Channels: A Stochastic Geometry Approach

In this paper, we introduce an analytical framework to compute the average rate of downlink heterogeneous cellular networks. The framework leverages recent application of stochastic geometry to other-cell interference modeling and analysis. The heterogeneous cellular network is modeled as the superposition of many tiers of Base Stations (BSs) having different transmit power, density, path-loss exponent, fading parameters and distribution, and unequal biasing for flexible tier association. A long-term averaged maximum biased-received-power tier association is considered. The positions of the BSs in each tier are modeled as points of an independent Poisson Point Process (PPP). Under these assumptions, we introduce a new analytical methodology to evaluate the average rate, which avoids the computation of the Coverage Probability (Pcov) and needs only the Moment Generating Function (MGF) of the aggregate interference at the probe mobile terminal. The distinguishable characteristic of our analytical methodology consists in providing a tractable and numerically efficient framework that is applicable to general fading distributions, including composite fading channels with small- and mid-scale fluctuations. In addition, our method can efficiently handle correlated Log-Normal shadowing with little increase of the computational complexity. The proposed MGF-based approach needs the computation of either a single or a two-fold numerical integral, thus reducing the complexity of Pcov-based frameworks, which require, for general fading distributions, the computation of a four-fold integral.

Error Performance of Multi-Antenna Receivers in a Poisson Field of Interferers: A Stochastic Geometry Approach

In this paper, we introduce an analytical framework for performance analysis and design of Single-Input-Multiple-Output (SIMO) wireless systems in the presence of noise, fading, and radio frequency interference produced by randomly distributed active interferers surrounding an intended probe receiver. The framework leverages recent application of stochastic geometry and Poisson Point Processes (PPPs) theory to network interference modeling. To assess the impact of spatial dependence across multiple receive-antennas, three models of network interference are studied: i) the isotropic model, where all receive-antennas see interferers belonging to the same PPP; ii) the independent model, where each receive-antenna sees interferers belonging to an independent PPP; and iii) the mixture model, which is a superposition of isotropic and independent interferences. Depending on the fading distribution of the interferers, the Nakagami-m fading parameter of the probe link, and the number of receive-antennas, either exact or upper-bound formulas of the error probability averaged over noise, fading, and spatial interference are given. Our analysis shows that, depending on the interference model, performance can either improve or get worse with multiple antennas at the receiver. The proposed analytical methodology is applicable to single- and multi-PPPs interference environments.

Potential Originality and Effectiveness: The Dynamic Definition of Creativity

Given the central role of creativity in the future post-information society, a call for a pragmatist approach to the study of creativity is advocated, that brings as a consequence the recognition of the dynamic nature of this phenomenon. At the foundation of the proposed new theoretical framework lies the definition of creativity itself, which is turned from static to dynamic through the introduction of the concept of potential originality and effectiveness. Starting from this central definition, and through the introduction of the auxiliary definitions for focus area, creativity goal, creative agent, creative potential of an agent, creative potential of an environment, creative process, product of a creative process, creativity potential of a process, representation of the product of a creative process, and estimator, we arrive at the definitions of creative achievement and creative inconclusiveness. Although both aspects are key in the creative process, creative inconclusiveness was not part of previous definitions, but it is argued that its role is fundamental for effective education in creativity. The new definitions are shown to have full backward compatibility with the extant corpus of scientific research in creativity, as well as forward effectiveness in suggesting novel investigation approaches to support the consideration of new theoretical hypotheses.

Blind least-squares estimation of carrier phase, Doppler shift, and Doppler rate for m-PSK burst transmission

A novel blind algorithm is proposed for joint carrier phase/Doppler shift least-squares (LS) estimation for burst transmission of m-PSK modulated data. The algorithm can be extended to include Doppler rate estimation. The performance of the algorithm is contrasted against that of known algorithms, and it is shown to be advantageous particularly for short bursts and large frequency offsets. The signal-to-noise ratio penalty with respect to the ideal estimation case is shown to be below 1 dB for a frequency error as large as 0.1 of the symbol rate and bursts as short as 20 symbols.

A Unified Urban Mobile Cloud Computing Offloading Mechanism for Smart Cities

The increasing urbanization level of the world population has driven the development of a smart city geographic system, conceived as a fully connected wide area characterized by the presence of a multitude of smart devices, sensors, and processing nodes aimed at distributing intelligence into the city. At the same time, the pervasiveness of wireless technologies has led to the presence of heterogeneous networks, operating simultaneously in the same city area. One of the main challenges in this context is to provide sustainable solutions able to jointly optimize the data transfer, exploiting heterogeneous networks, and the data processing, exploiting heterogeneous devices, for managing smart city applications for citizens communities. In this article, the UMCC framework is developed, introducing a mobile cloud computing model describing the flows of data and operations taking place in the smart city. In particular, we focus on the proposal of a unified offloading mechanism where communication and computing resources are jointly managed, allowing load balancing among the different entities in the environment, delegating both communication and computation tasks in order to satisfy the smart city application requirements. This allows us to cope with the limited battery power and computation capacity of smart mobile devices and plays a key role in a smart environment where wireless communication is of utmost relevance, particularly in the mobility and traffic control domains.

An Eye-Tracking Analysis of Irrelevance Processing as Moderator of Openness and Creative Performance

Openness has been identified as one of the personality traits with stronger association to creativity into the Five-Factor Model of personality. But what are the psychological mechanisms that relate Openness and creative performance? The present paper aims at responding to this question, exploring in particular whether the attentional processing of apparently irrelevant information (irrelevance processing) can act as a moderator within the relation between Openness and creativity. To this aim, a visual version of the Unusual Uses Task was developed and, using an eye-tracker methodology, the attentional processing of both information that is central to the task, and information that is “apparently” irrelevant for its execution was measured. The results showed a moderating effect of irrelevance processing on the role of Openness in both creative achievement and originality of the uses produced by the participants, with creativity reaching higher levels in individuals who gave attention to irrelevant information and were characterized by a high level of Openness. These findings establish attentive processing as a central psychological mechanism to explain the relationship between Openness and creativity.

Design and Analysis of Deterministic Distributed Beamforming Algorithms in the Presence of Noise

This paper presents a new deterministic closed-loop phase-alignment algorithm based on quantized feedback from the receiver for distributed beamforming. In contrast with previously proposed methods, which entailed repeated transmissions from all the nodes in the network, this new algorithm requires each node to transmit only once during the synchronization cycle. This drastically reduces the amount of power consumed to achieve phase alignment, yet the new algorithm converges at least as fast as all other existing schemes. In contrast with previous analyses of distributed beamforming based on random phase updates, where noise had been disregarded, here it is explicitly included in the models and shown to have a considerable effect that cannot be ignored. With and without noise, analytical expressions that characterize the performance of the new algorithm are provided, with emphasis on various limiting regimes of interest.

Adaptive coding and modulation techniques for next generation hand-held mobile satellite communications

In the last years we are seeing the increasing presence of multimedia applications together with a wide variety of terminals, from the PCs to the notebooks, from the smartphones to the tablets. In order to exploit such advanced services, ubiquitous and broadband connections are required. While urban or suburban areas can be covered by using terrestrial wireless broadband networks, there are several rural or low populated areas with narrowband access. To this aim, satellite community has developed in the last years two communications standards specifically suited for mobile communications, i.e., DVB-SH and DVB-RCS NG. Among others they consider adaptive waveforms techniques for increasing the system reliability and throughput aiming to exploit the variable channel behavior. Adaptive coding and modulation (ACM) belongs to this family of algorithms, by adapting the modulation and coding scheme based on the channel behavior. In this paper we focus on a state adaptive algorithm suited for mobile applications.

Cognitive Radio based Smart Grid Networks

The conventional power grid has several drawbacks and a new powerful Smart Grid perspective has been recently introduced. The Smart Grid principle, allowing to efficiently manage an electrical grid network, needs to exploit a communication network for interconnecting the Smart Grid devices. An increasing interest is toward wireless communications due to their higher flexibility. Within this context Cognitive Radio (CR) techniques has been introduced aiming to exploit more efficiently the radio spectrum resources; to this aim CR based Smart Grids will be reviewed as a possible solution for implementing an effective Smart Grid Network. Furthermore, a set of new methods will be introduced to solve some challenges introduced by CR based Smart Grids.

Estimating Creativity with a Multiple-Measurement Approach Within Scientific and Artistic Domains

This article presents the structure and the composition of a newly developed multifaceted test battery for the measurement of creativity within scientific and artistic domains. By integrating existing procedures for the evaluation of creativity, the new battery promises to become a comprehensive assessment of creativity, encompassing both domain-general and domain-specific components. In particular, the test battery was designed for the measurement of the 2 main stages of the creative thinking process: ideation and evaluation. The test battery also includes 2 measures of creative achievement and can be used to assess professional levels of creativity in artistic and scientific creativity, as well as everyday creativity. Because creative thinking is not an isolated phenomenon in human behavior, the battery includes the measurement of 2 constructs, intelligence and personality, both of which are highly relevant for creativity. Preliminary results from a vast administration campaign of this test battery are presented.