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Recently, new standards have emerged in the telecommunication industry. These standards provide an open global specification that enables mobile devices to access and interact with information and services instantly. Paving the way to the emergence of new added-values services, these devices require more and more a localization agent. When deployed, these wireless resources have to operate in non-stationary...
In this paper, we consider an impulse-based ultra- wideband (UWB) receiver and assess the performance of different multiple access and modulation schemes, including time-hopping pulse position modulation (TH-PPM), time-hopping binary phase shift keying (TH-BPSK), and BPSK-BPSK, under both the additive white Gaussian noise (AWGN) and indoor multipath (CM3) channel assumptions. The assumed receiver...
Estimation of the carrier to noise ratio (CNR) is one of the most important functionalities of the GPS/Galileo receivers. However, the conventional GPS receivers are not able to satisfy the CNR estimation requirements for the location based services, E-911, and moderate indoor reception. In this paper we derive a total of seven moment based CNR estimators and present the results for the simulation...
This paper presents a developed inertial navigation multi sensor node, along with an efficient calibration technique to improve the accuracy of the measurement acquired from a set of inertial sensors and magnetic encoder. The implemented node consists of a high resolution magnetic compass sensor, a distance sensor works as magnetic encoder, an accelerometer and a gyroscope to detect the linear and...
We consider the problem of tracking multiple targets in the presence of noise and a mixture of line-of-sight (LoS) and non-line-of-sight (NLoS) conditions. The targets are assumed to describe independent trajectories with non-stationary (dynamic) statistics, i.e., with variable velocities and accelerations (limited in absolute value). These moving targets are observed by fixed anchors, which measure...
Localization of sensor nodes is one of the key issues in wireless sensor networks. It is a precondition for a variety of scenarios as well as geographic clustering and routing. A simple approach for coarse grained localization is weighted centroid localization (WCL), which, unfortunately, comes with some drawbacks. Therefore, we present the "Adaptive WCL" (AWCL) algorithm that outperforms...
This paper presents positioning results determined by a multi-layer, packet based OMNet++ simulator for communication and positioning in an autonomous wireless sensor network. The simulator includes an IR-UWB physical layer model considering the impact of multi-user interference, a highly flexible MAC layer which performs physical layer adaptations to optimize the total link performance, and a ranging...
This paper describes the extension to a noncoherent impulse radio (IR) ultra-wide band (UWB) transceiver for precise time-of-arrival (TOA) measurements. The extension provides a time resolution of 260 picoseconds, which allows a precise indoor localization. The concept of this extension is especially dedicated to the known drawbacks of energy detection (non-coherent) receivers. The discussion of the...
High-sensitivity GPS receivers allow to track very weak GPS signals (-180 dBW or even below) that are due to strong signal attenuation by e.g. foliage or constructive materials. Consequently, they outperform classical geodetic receivers of more than 30 dB and enable the signal tracking and positioning even indoors. This increase of GPS availability opens up new applications such as seamless outdoor-indoor...
PNaFF (personal navigation filter framework) is a comprehensive simulation and filtering test bench that is being developed within the Personal Positioning Research Group at the Department of Mathematics of Tampere University of Technology. Hybrid positioning is a process where measurements from different sources are used to obtain position estimate. PNaFF provides tools for comparison and visualization...
Ultra-wideband (UWB) has become one of the key technologies in wireless communication industries. In this paper we discuss and evaluate the performance of UWB under different channel conditions when it is applied for wireless sensors. The simulation was carried out for various detection and modulation schemes. Simulation results confirm that UWB with coherent detection outperforms the noncoherent...
It is known that Particle Filter and Map Filtering techniques can be used to improve the performance of positioning systems, such as Pedestrian Dead Reckoning (PDR). In previous research on indoor navigation, it was generally assumed that detailed building plans were available. However, in many emer gency / rescue scenarios, there may be only limited building plan information on hand. The purpose...
The paper is a study of the errors induced by the inertial sensors in a bidimensional horizontal navigator. In the first stage, the basic equations of the navigator and the navigation solution are presented. Starting from the navigator mathematical model it is realized an error model for this, a model which considers the errors of the used inertial sensors. It is realized the numerical simulation...
While in outdoor scenarios the global positioning system (GPS) provides accurate mobile station (MS) location estimates in the majority of cases, in dense urban and indoor scenarios GPS often cannot provide reliable MS location estimates, due to the attenuation or complete shadowing of the satellite signals. The existing cellular radio network (CRN)-based localization methods, however, provide MS...
We demonstrate a low-cost, low-power, and small form factor solution to drift-free high-resolution vertical positioning by fusing MEMS accelerometers with MEMS barometric altimeter. In this system, the highly responsive but drift-prone aspect of the MEMS accelerometers is stabilized by barometric altimeter and high-fidelity height tracking is achieved. Typical vertical human movements such as walking...
As technology advances, detailed data on the position of moving objects, such as humans and vehicles is available. In order to discover groups of mobile objects that usually move in similar ways we propose an incremental clustering algorithm that clusters mobile objects according to similarity of their movement patterns. The proposed clustering algorithm uses a new, "data-amount-based" similarity...
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