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In this paper, we propose a geometric positioning technique for cooperative localization in Wireless Networks. The proposed technique is based on building geometric constraints from radio observables. These constraints are then merged to estimate the true position. In this paper we address situations where blind nodes, due to the lack of radio observables, cooperate to estimate their positions. Compared...
In this paper, we present a comparison between Off-Body channel characteristics estimated with Space-Alternating Generalized Expectation-Maximization (SAGE) algorithm from measurement data and those obtained from ray-tracing simulated data. Measurement data were obtained considering a body-worn antenna on a phantom and an external one simulating an access point. The chosen simulation approach takes...
This paper presents a novel mobility model to perform realistic simulations of human movements and behav-iors. The proposed model is based on discrete event simulation and graph theory. The proposed model is implemented in a wireless propagation simulator and used to evaluate various wireless network protocols including: propagation, localization and communication.
PyLayers is a new open source radio simulator. It has been designed to evaluate localization algorithm performances through the realistic simulation of location-dependent parameters (LDPs) in heterogeneous mobile radio networks. The radio channel is synthesized by using a novel graph-based ray tracing method which has been introduced in order to improve performances in mobile ray-tracing scenarios...
Ray tracing simulators show higher accuracy in modeling propagation of radio waves. This RT based modeling has been used for designing wireless communications systems. Recently, these RT tools have been applied for the designing of localization techniques and systems. This paper regards the application of ray tracing tools in radio propagation modeling for ultra wide band localization applications...
We consider positioning in the scenario where only two reliable range estimates, and few less reliable power observations are available. Such situations are difficult to handle with numerical maximum likelihood methods which require a very accurate initialization to avoid being stuck into local maxima. We propose to first estimate the support region of the two peaks of the likelihood function using...
In this paper, we propose a geometric positioning method for hybrid wireless networks, based on a set membership method. Three common types of radio observables are considered for the position estimation: range, difference of ranges and received power. This paper details how to build geometric constraints from observables, and how to merge them to estimate the position. Given a realistic scenario,...
In this paper, expressions of Cramer Rao lower bounds (CRLB) are derived for non-hybrid and hybrid localization techniques based on RSSI, TOA, and TDOA under Gaussian uncorrelated measurements assumption. Simulations are then carried out using realistic radio parameters values in order to compare different non-hybrid and hybrid localization techniques. CRLBs expressions and simulations show that the...
In this paper, we exploit the semidefinite programming and the Cramer Rao lower bound techniques to study the hybrid fusion of RSSI and TOA. A semidefinite program is developed to fuse these two location-dependent parameters. The Cramer Rao lower bound expressions are also developed in order to assess theoretical performances of the RSSI and TOA fusion. In order to evaluate this localization scheme,...
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