Synchronization and Detection Techniques for Navigation and Communication Systems

Synchronization is a key issue in any communication system, but it becomes fundamental in the navigation systems, which are entirely based on the estimation of the time delay of the signals coming from the satellites. Thus, even if synchronization has been a well known topic for many years, the introduction of new modulations and new physical layer techniques in the modern standards makes the traditional synchronization strategies completely ineffective. For this reason, the design of advanced and innovative techniques for synchronization in modern communication systems, like DVB-SH, DVB-T2, DVB-RCS, WiMAX, LTE, and in the modern navigation system, like Galileo, has been the topic of the activity. Recent years have seen the consolidation of two different trends: the introduction of Orthogonal Frequency Division Multiplexing (OFDM) in the communication systems, and of the Binary Offset Carrier (BOC) modulation in the modern Global Navigation Satellite Systems (GNSS). Thus, a particular attention has been given to the investigation of the synchronization algorithms in these areas.

Code synchronization and interference management techniques for satellite navigation and communications

This thesis collects the outcomes of a Ph.D. course in Telecommunications engineering and it is focused on enabling techniques for Spread Spectrum (SS) navigation and communication satellite systems. It provides innovations for both interference management and code synchronization techniques. These two aspects are critical for modern navigation and communication systems and constitute the common denominator of the work. The thesis is organized in two parts: the former deals with interference management. We have proposed a novel technique for the enhancement of the sensitivity level of an advanced interference detection and localization system operating in the Global Navigation Satellite System (GNSS) bands, which allows the identification of interfering signals received with power even lower than the GNSS signals. Moreover, we have introduced an effective cancellation technique for signals transmitted by jammers, exploiting their repetitive characteristics, which strongly reduces the interference level at the receiver. The second part, deals with code synchronization. More in detail, we have designed the code synchronization circuit for a Telemetry, Tracking and Control system operating during the Launch and Early Orbit Phase; the proposed solution allows to cope with the very large frequency uncertainty and dynamics characterizing this scenario, and performs the estimation of the code epoch, of the carrier frequency and of the carrier frequency variation rate. Furthermore, considering a generic pair of circuits performing code acquisition, we have proposed a comprehensive framework for the design and the analysis of the optimal cooperation procedure, which minimizes the time required to accomplish synchronization. The study results particularly interesting since it enables the reduction of the code acquisition time without increasing the computational complexity. Finally, considering a network of collaborating navigation receivers, we have proposed an innovative cooperative code acquisition scheme, which allows exploit the shared code epoch information between neighbor nodes, according to the Peer-to-Peer paradigm.

Data integration, real-time synchronization and RESTful Web Service

Analisi e sviluppo di procedure di importazione dati per un integratore di annunci immobiliari dedicato alla vendita di soggiorni turistici in case vacanza. Il documento tratta inoltre l'implementazione di un Web Service conforme all'architettura RESTful per l'accesso e l'esportazione dei dati a soggetti terzi autorizzati tramite Digest Authentication.

Differences in the quality of interpersonal care in complementary and conventional medicine

The study was part of a nationwide evaluation of complementary and alternative medicine (CAM) in Swiss primary care. The aim of the study was to compare patient-physician relationships and the respective patient-reported relief of symptoms between CAM and conventional primary care (COM).

Measuring attitudes, behaviours, and influences in inner city victims of interpersonal violence (VIVs) - a Swiss emergency room pilot study

Background Switzerland is confronted with the problem of interpersonal violence. Violence is in the increase and the potential for aggression seems to be rising. Observations by hospitals discern an appalling increase of the severity of the injuries. The aim of this study is to collect accurate information about the social environment, the motivation and possible reasons for violence. We also intend to investigate whether sociocultural, or ethnic differences among male victims exist. Materials and methods For the first time in Switzerland, this survey employed a validated questionnaire from the division of violence prevention, Atlanta, Georgia. The first part of the questionnaire addressed social and demographic factors which could influence the risk of violence: age, gender, duration of stay in Switzerland, nationality and educational level. Beside these social structural factors, the questionnaire included questions on experience of violent offences in the past, information about the most recent violent offence and intra and interpersonal facts. The questionnaire itself consists of 27 questions, translated into German and French. In a pilot study, the questionnaire was checked with adolescents for feasibility and comprehensibility. Results 69 male VIVs were interviewed at two hospitals in the Canton of Bern. Most of the adolescents emphasised that weapons were not used during their confrontations. It is astonishing that all of the young men considered themselves to be victims. Most of the brawls were incited after an exchange of verbal abuse and provocations with unfamiliar individuals. The rivals could neither be classified with the help of ethnic categories nor identifiable groups of the youth scenes. The incidents took place in scenes, where violence was more likely to happen. Interestingly and contrary to a general perception the offenders are well integrated into sport and leisure clubs. A further surprising result of our research is that the attitude towards religion differs between young men with experience of violence and non-violent men. Discussion Youth violence is a health issue, which concerns us globally. The human and economic toll of violence on victims and offenders, their families, and on society in general is high. The economic costs associated with violence-related illness and disability is estimated to be millions of Swiss francs each year. Physicians and psychologists are compelled to identify the factors, which cause young people to be violent, to find out which interventions prove to be successful, and to design effective prevention programs. The identification of effective programs depends on the availability of reliable and valid measures to assess changes in violence-related attitudes. In our efforts to create healthier communities, we need to investigate; document and do research on the causes and circumstances of youth violence.

Review of Encyclopedia of Interpersonal Violence

With more than five hundred entries, Encyclopedia of Interpersonal Violence defines key terms and provides information about legislation, public policy, theoretical perspectives, and programs dedicated to assisting victims and raising awareness of these devastating social problems. Encyclopedia of Interpersonal Violence features nine pages of material with entries that cover anti-gay gender motivated, racially motivated, and religiously motivated crimes as well as information about the criminal justice response and legislation.

Increased phase synchronization during continuous face integration measured simultaneously with EEG and fMRI

Gamma zero-lag phase synchronization has been measured in the animal brain during visual binding. Human scalp EEG studies used a phase locking factor (trial-to-trial phase-shift consistency) or gamma amplitude to measure binding but did not analyze common-phase signals so far. This study introduces a method to identify networks oscillating with near zero-lag phase synchronization in human subjects.

Cranio-maxillofacial injuries in victims of interpersonal violence

Recent research has indicated an increase in the severity of head injuries in Switzerland. The aim of the present study was to describe the epidemiological features of cranio-maxillofacial (CMF) injuries due to interpersonal violence in patients at the Bern University Hospital Emergency Department (ED), based on injury patterns.

Is gamma band EEG synchronization reduced during auditory driving in schizophrenia patients with auditory verbal hallucinations?

Auditory verbal hallucinations (AVH) in schizophrenia patients assumingly result from a state inadequate activation of the primary auditory system. We tested brain responsiveness to auditory stimulation in healthy controls (n=26), and in schizophrenia patients that frequently (n=18) or never (n=11) experienced AVH. Responsiveness was assessed by driving the EEG with click-tones at 20, 30 and 40Hz. We compared stimulus induced EEG changes between groups using spectral amplitude maps and a global measure of phase-locking (GFS). As expected, the 40Hz stimulation elicited the strongest changes. However, while controls and non-hallucinators increased 40Hz EEG activity during stimulation, a left-lateralized decrease was observed in the hallucinators. These differences were significant (p=.02). As expected, GFS increased during stimulation in controls (p=.08) and non-hallucinating patients (p=.06), which was significant when combining the two groups (p=.01). In contrast, GFS decreased with stimulation in hallucinating patients (p=0.13), resulting in a significantly different GFS response when comparing subjects with and without AVH (p<.01). Our data suggests that normally, 40Hz stimulation leads to the activation of a synchronized network representing the sensory input, but in hallucinating patients, the same stimulation partly disrupts ongoing activity in this network.