Average performance analysis of circular and hyperbolic geolocation

A comparative performance analysis of four geolocation methods in terms of their theoretical root mean square positioning errors is provided. Comparison is established in two different ways: strict and average. In the strict type, methods are examined for a particular geometric configuration of base stations(BSs) with respect to mobile position, which determines a given noise profile affecting the respective time-of-arrival (TOA) or timedifference- of-arrival (TDOA) estimates. In the average type, methods are evaluated in terms of the expected covariance matrix of the position error over an ensemble of random geometries, so that comparison is geometry independent. Exact semianalytical equations and associated lower bounds (depending solely on the noise profile) are obtained for the average covariance matrix of the position error in terms of the so-called information matrix specific to each geolocation method. Statistical channel models inferred from field trials are used to define realistic prior probabilities for the random geometries. A final evaluation provides extensive results relating the expected position error to channel model parameters and the number of base stations.Peer Reviewe

Algoritmo de Scheduling M-LWDF : simulación para la provisión de calidad de servicios en entornos multiusuario con canales variantes

En sistemas de transmisión de alta velocidad en canales wireless, donde el espectro es un recurso altamente limitado, se hace necesaria la implementación de algoritmos de reparto de los recursos si se pretende cumplir con unos determinados requerimientos en términos de tasa de transmisión o de retardo máximo de los paquetes. El presente artículo pretende mostrar cómo los algoritmos de Scheduling (y en particular el algoritmo M-LWDF) pueden ofrecer mejores prestaciones en términos de tasa media de transmisión respecto a los algoritmos tradicionalesde reparto de recursos, los cuales no suelen prestar atención a las circunstancias individuales que presentan los diferentes usuarios del sistemaPeer Reviewe

Algoritmo de Scheduling M-LWDF : simulación para la provisión de calidad de servicios en entornos multiusuario con canales variantes

En sistemas de transmisión de alta velocidad en canales wireless, donde el espectro es un recurso altamente limitado, se hace necesaria la implementación de algoritmos de reparto de los recursos si se pretende cumplir con unos determinados requerimientos en términos de tasa de transmisión o de retardo máximo de los paquetes. El presente artículo pretende mostrar cómo los algoritmos de Scheduling (y en particular el algoritmo M-LWDF) pueden ofrecer mejores prestaciones en términos de tasa media de transmisión respecto a los algoritmos tradicionalesde reparto de recursos, los cuales no suelen prestar atención a las circunstancias individuales que presentan los diferentes usuarios del sistemaPeer Reviewe

Feasibility study for a spacecraft navigation system relying on pulsar timing information

Estudi de fiabilitat per un sistema de navegacio d'espai profund basat en referencies de radio-estrelles pulsants (pulsar).Preprin

Average performance analysis of circular and hyperbolic geolocation

A comparative performance analysis of four geolocation methods in terms of their theoretical root mean square positioning errors is provided. Comparison is established in two different ways: strict and average. In the strict type, methods are examined for a particular geometric configuration of base stations(BSs) with respect to mobile position, which determines a given noise profile affecting the respective time-of-arrival (TOA) or timedifference- of-arrival (TDOA) estimates. In the average type, methods are evaluated in terms of the expected covariance matrix of the position error over an ensemble of random geometries, so that comparison is geometry independent. Exact semianalytical equations and associated lower bounds (depending solely on the noise profile) are obtained for the average covariance matrix of the position error in terms of the so-called information matrix specific to each geolocation method. Statistical channel models inferred from field trials are used to define realistic prior probabilities for the random geometries. A final evaluation provides extensive results relating the expected position error to channel model parameters and the number of base stations.Peer Reviewe

Average performance analysis of circular and hyperbolic geolocation

A comparative performance analysis of four geolocation methods in terms of their theoretical root mean square positioning errors is provided. Comparison is established in two different ways: strict and average. In the strict type, methods are examined for a particular geometric configuration of base stations(BSs) with respect to mobile position, which determines a given noise profile affecting the respective time-of-arrival (TOA) or timedifference- of-arrival (TDOA) estimates. In the average type, methods are evaluated in terms of the expected covariance matrix of the position error over an ensemble of random geometries, so that comparison is geometry independent. Exact semianalytical equations and associated lower bounds (depending solely on the noise profile) are obtained for the average covariance matrix of the position error in terms of the so-called information matrix specific to each geolocation method. Statistical channel models inferred from field trials are used to define realistic prior probabilities for the random geometries. A final evaluation provides extensive results relating the expected position error to channel model parameters and the number of base stations.Peer Reviewe

Algoritmo de Scheduling M-LWDF : simulación para la provisión de calidad de servicios en entornos multiusuario con canales variantes

En sistemas de transmisión de alta velocidad en canales wireless, donde el espectro es un recurso altamente limitado, se hace necesaria la implementación de algoritmos de reparto de los recursos si se pretende cumplir con unos determinados requerimientos en términos de tasa de transmisión o de retardo máximo de los paquetes. El presente artículo pretende mostrar cómo los algoritmos de Scheduling (y en particular el algoritmo M-LWDF) pueden ofrecer mejores prestaciones en términos de tasa media de transmisión respecto a los algoritmos tradicionalesde reparto de recursos, los cuales no suelen prestar atención a las circunstancias individuales que presentan los diferentes usuarios del sistemaPeer Reviewe

Feasibility study for a spacecraft navigation system relying on pulsar timing information

Estudi de fiabilitat per un sistema de navegacio d'espai profund basat en referencies de radio-estrelles pulsants (pulsar)

Feasibility study for a spacecraft navigation system relying on pulsar timing information

Estudi de fiabilitat per un sistema de navegacio d'espai profund basat en referencies de radio-estrelles pulsants (pulsar)

Pulsar navigation

This paper evaluates the fundamental performance bounds, signal processing and technological complexity associated with the synchronization to radio and X-ray pulsars as well as its impact on the positioning accuracy of an autonomous spacecraft navigation system. Performance analysis of synchronization and location algorithms builds on Maximum Likelihood (ML) estimation which provides, asymptotically, unbiased minimum variance estimates with mean square error strictly approaching the Cramer-Rao Lower Bound (CRLB).Peer ReviewedPostprint (published version