Ricerc@Sapienza

Narrowband Internet of Things (NB-IoT) is gaining momentum as a promising technology for massive machine type communication. Given that its deployment is rapidly progressing worldwide, measurement campaigns and performance analyses are needed to better understand the system and move toward its enhancement. With this aim, this article presents a large-scale measurement campaign and empirical analysis of NB-IoT on operational networks, and discloses valuable insights in terms of deployment strategies and radio coverage performance.

Compact high-gain wideband antenna systems for through-the-wall imaging and wireless communications, featuring 160% fractional bandwidth, are presented. Each radiating system, consisting of two orthogonal Vivaldi antennas forming a cross-shaped configuration so to excite linear (horizontal/vertical) and circular polarization (CP), is equipped with a top-mount spherical-axicon dielectric lens. The optimized shaping of the lens and of the outer edge Vivaldi arms allow achieving gain levels exceeding 15dBi with good front-to-back-ratio.

In this paper we propose a solution to the problems of detecting a generally correlated stochastic
output delay sequence of a linear system driven by Gaussian noise. This is the model for uncertain
observations resulting from losses in the propagation channel due to fading phenomena or packet
dropouts that is common in wireless sensor networks, networked control systems, or remote sensing
applications. The solution we propose consists of a nonlinear detector which identifies online the