Are carrier-to-noise algorithms equivalent in all situations?

This paper describes methods to estimate the carrier to noise ratio in GNSS application

Benets of tight coupled architectures for the integration of GNSS receiver and Vanet transceiver

Vehicular adhoc networks (VANETs) are one emerging type of networks that will enable a broad range of applications such as public safety, traffic management, traveler information support and entertain ment. Whether wireless access may be asynchronous or synchronous (respectively as in the upcoming IEEE 8021.11p standard or in some alternative emerging solutions), a synchronization among nodes is required. Moreover, the information on position is needed to let vehicular services work and to correctly forward the messages. As a result, timing and positioning are a strong prerequisite of VANETs. Also the diffusion of enhanced GNSS Navigators paves the way to the integration between GNSS receivers and VANET transceiv ers. This position paper presents an analysis on potential benefits coming from a tightcoupling between the two: the dissertation is meant to show to what extent Intelligent Transportation System (ITS) services could benefit from the proposed architectur

A fully digital model for Kalman filters

The Kalman filter is a mathematical method, whose purpose is to process noisy measurements in order to obtain an estimate of some relevant parameters of a system. It represents a valuable tool in the GNSS area, with some of its main applications related to the computation of the user PVT solution and to the integration of GNSS receivers with INS or other sensors. The Kalman filter is based on a state space representation, that describes the analyzed system as a set of differential equations that establishes the connections between the inputs, the outputs and the state variables of the analyzed system. In the continuous time domain there exists a large class of physical processes with a time evolution well described by means of stochastic differential equations. A typical problem is the need for an equivalent system in the discrete time, due to the discrete nature of the data to be processed. In the literature, it is quite common to solve this problem in the continuous time domain and to approximate the solution using a Taylor series approximation, to obtain an approximate discrete time version of the continuous time problem. By the way, other methods exist, based on the possibility to transform a continuous-time system to a discrete-time system by means of transformations from the Laplace complex plane to the z plane. These methods are widely used in the digital signal processing community, for example, to design digital filters from their analog counterparts. The main advantage of this approach is that it is very easily implemented by applying some mechanical rules. Moreover the nature of the approximation introduced by the Laplace-z transformation is a-priori known and clearly readable in the frequency domain. In the following the classical methods based on the Taylor approximation and on the Laplace-z transformations will be analyzed and compare

GNSS signal acquisition in the presence of sign transitions

The next generation of Global Navigation Satellite Systems (GNSS), such as Galileo [1] and GPS modernization [2], will use signals with equal code and bit periods, which will introduce a potential sign transition in each segment of the signal processed in the acquisition block. If FFT is used to perform the correlations a sign transition occurring within the integration time may cause a splitting of the main peak of the Cross Ambiguity Function (CAF) into two smaller lobes along the Doppler shift axis [3]. In this paper a method to overcome the possible impairments due to the lobe splitting is proposed and validated by simulatio

DVB-T Positioning with a One Shot Receiver

In this paper a one shot receiver for DVB-T positioning is presented. DVB-T SFN signals can be used as Signals-of-Opportunity in urban environment to assist GNSS in case the GNSS-only positioning shows degraded performance. The normal mechanism of DVB-T positioning involves a tracking stage to refine the coarse delay estimation obtained by the acquisition stage. However due to the high SNR of DVB-T signals, the delay estimation can be refined by some simple interpolation methods with lower complexity and power consumption. Two different interpolation methods, linear interpolation and sinc interpolation, are analysed in the paper. Simulation results show that the one shot receiver proposed in this paper behaves as a tracking-based receiver, but exhibits a lower complexit

On the use of a signal quality index applying at tracking stage level to assist the RAIM system of a GNSS receiver

In this work, a novel signal processing method is proposed to assist the Receiver Autonomous Integrity Monitoring (RAIM) module used in a receiver of Global Navigation Satellite Systems (GNSS) to improve the integrity of the estimated position. The proposed technique represents an evolution of the Multipath Distance Detector (MPDD), thanks to the introduction of a Signal Quality Index (SQI), which is both a metric able to evaluate the goodness of the signal, and a parameter used to improve the performance of the RAIM modules. Simulation results show the effectiveness of the proposed method

L'altra "P" del marketing : il Public engagement come leva del marketing nell'era 2.0

2014 - 2015The role of universities in recent years is changing towards a proactive and utilitarian vision. Universities, State and Industry form a triple helix with the potential for economic and social development of the community. In this sense, activities involving the university stakeholders can have an impact on relationships that can favor the accomplishment of the third mission of the university. Since public engagement entails the myriad of ways in which activities and benefits of higher education and research can be shared with the public, it can be considered a useful tool for adopting a new approach toward knowledge-transfer beyond the academic boundaries. In a marketing point of view, public engagement is another “P” in the higher education marketing mix by contributing to the strengthening of the relations with the stakeholders. To accomplish this mission, online communication seems to be a valuable channel for engaging better the public and divulging university activities on the Internet. Despite the potential of online communication, yet there are no studies that have investigated the public engagement online and measured such aspects of the construct emerge more in digital communication. Moreover little has been investigated about which forms of communication used on the social networks have a greater capacity for involvement. For this reason, after a deep examination of former studies in management about public engagement, this thesis focuses on the different constructs of University public engagement. By studying communication on social media and analyzing the websites of a sample of foreign universities (50 European universities and 86 US/UK universities), this thesis identifies the characteristics of communication in online public engagement that might successfully engage the stakeholders, and investigates the communication approaches currently adopted in online public engagement. The thesis concludes by claiming that public engagement is another “P” in the higher education marketing mix, and by highlighting characteristics, benefits and consequences of the public engagement construct for community-oriented Universities. [edited by Author]XIV n.s

Kalman filter-based ARAIM algorithm for integrity monitoring in urban environment

This work proposes an adaptation of Advanced Receiver Autonomous Integrity Monitoring (ARAIM) algorithm for snapshot integrity monitoring in urban environment, using Kalman Filter (KF) as underlying positioning method. This new method can follow the changes of signal quality, maintaining good performance under the effect of multipath which is always presents in urban areas. Performance analysis using both simulated and real data validates the method, and comparison with conventional ARAIM algorithm (which was developed for aviation) further consolidates the suitability of the proposed method for urban scenario. Keywords: ARAIM, Integrity monitoring, Kalman filter, Multipath, Urban environmen