Average Instantaneous, Unimodal and Multimodal Scattering Responses in Spatial Gaussian Channels

The long-standing problem of identifying the scattering mechanism that triggers the observance of a heavytailed power azimuth spectrum is underdertaken using a geometrybased stochastic approach. More specifically, the unimodal power azimuth spectrum (PAS) and joint power angular scattering response (PASR) are derived under the 2-D Gaussian scattering model. At first, it is formally shown that, under free-spacepropagation, a Gaussian scatter distribution in 2-D space gives rise to an angular power spectrum that may be well modeled by the Gaussian function. Numerical results are presented for higher path-loss exponents, where it is shown that heavy-tailed functions such as the Lorentzian and Laplacian functions provide good fits to the derived spectrum. To complement earlier research works in this area, a recently introduced geometry-based stochastic model is extended in order to express the instantaneous multimodal PASR, which significantly contributes to the estimated correlation statistics as shown in the paper. The 2-D spatial channel model developed herein, allows the distance from the observation point to vary, which enhances the validity of the derived PAS and PASR. Statistical results are provided for various distances from the observation point in order to facilitate any potential practical use of the derived 2-D model. Finally, an analytical expression for the correlation experienced between two antenna patterns is derived under the proposed model

A Three-Dimensional Angular Scattering Response Including Path Powers

In this paper the angular power spectrum exhibited under a three-dimensional (3-D) Gaussian scatter distribution at fixed observation points in space is investigated. Typically, these correspond to the mobile and base units respectively. Unlike other spatial channel models, the derived model accounts for the distance to each scatterer from the observation point and transforms distances into power values under the assumption of free-space propagation. The proposed 3-D spatial channel model follows a non-central approach in terms of the scatter distribution in space, which means that the angular power field at the base unit need not be due to a scatter distribution centered exactly at the mobile. Derivations are provided for the angular and power domains and as shown by conditioning the distance, the angular field reduces to the von-Mises Fisher distribution. Most importantly, this work undertakes the problem of a Gaussian angular power spectrum observed in radio propagation channel measurements and provides a formal theoretical framework of the experimental investigations found in literature. The proposed model denotes that a Gaussian scatterer distribution in space gives rise to a Gaussian angular power spectrum and a Gaussian angular power density in the azimuth and elevations fields. The proposed 3-D spatial channel model might be used for evaluating the performance of current and future multi-element wireless communication networks

Spherical statistics in multi-element antenna systems

EThOS - Electronic Theses Online ServiceGBUnited Kingdo

The Fisher-Bingham spatial correlation model for multielement antenna systems

In this paper, XXXX we study the effect of the elevation of incoming multipaths at a multielement antenna receiver by using a novel 3-D approach. It is shown that under a more general 3-D angle-of-arrival (AoA) model, namely, the Fisher-Bingham five-parameter (FB5) distribution, the spatial fading correlation (SFC) that is experienced between the adjacent antenna array elements decreases as the elevation increases. The FB5 distribution does not have a known series expansion, and therefore, the defining SFC integral can only numerically be evaluated. The proposed SFC function is further extended to capture the effect of multiple clusters of scatterers in the propagation channel. We, therefore, propose a mixture SFC function that is scaled according to the probability that each cluster contributes to the channel. The parameters of the individual components that constitute the mixture are estimated by using a soft expectation maximization (soft-EM) algorithm. The results indicate that the proposed model fits well with the data obtained from a multiple-input-multiple-output (MIMO) measurement campaign in the city of Ilmenau, Germany

The FB5 distribution and its application in wireless communication

Recently, the third generation partnership standards bodies (3GPP/3GPP2) have defined a channel model for multiple input multiple output (MIMO) systems. This model is a 2-dimensional (2D) model where the propagating plane waves are assumed to arrive only from the azimuthal direction and does not include the elevation domain. As a result of this assumption the derived angle of arrival (AoA) distribution is characterized only by the azimuth direction of these waves. In this paper the AoA distribution of multipaths is modeled in a novel 3-dimensional (3D) approach. The Von Mises Fisher (VMF) and Fisher Bingham (FB5) probability density functions (PDF) are used to describe their distribution within the propagation environment in azimuth and co-latitude. More specifically two separate models are proposed. The first model uses a mixture of VMF distributions and the second one uses a mixture of FB5 and VMF distributions. The parameters of the individual cluster of scatterers within the mixture are derived and an estimation of those parameters is achieved using the expectation maximization (EM) algorithm. The two models are compared. The results indicate that both mixture models perform really well. However the FB5 mixture model is proposed because it is more flexible. Both models are validated with the use of MIMO experimental data obtained from a measurement campaign in Germany

3-dimensional channel modeling using spherical statistics for multiple input multiple output systems

This model is a 2D model where the propagating plane waves are assumed to arrive only from the azimuthal direction and does not include the elevation domain. As a result of this assumption the derived angle of arrival (AoA) distribution is characterized only by the azimuth direction of these waves. In this paper the distribution of scatterers is modeled in a novel 3D approach. The Von Mises Fisher (VMF) probability density function (PDF) is used to describe their distribution within the propagation environment in azimuth and coelevation. As a result the AoA distribution of the incoming multipaths is characterized in the same way. More specifically the model proposed uses a mixture of VMF distributions. A mixture can be composed of any number of clusters and this is environment/clutter specific. The parameters of the individual clusters of scatterers within the mixture are derived and an estimation of those parameters is achieved using the soft-expectation maximization (EM) algorithm. The results indicate that the proposed model fits well with MIMO experimental data obtained from a measurement campaign in Germany. The measurements obtained from the RUSK channel sounder were post-processed using the RiMAX algorithm. The data was subsequently clusterized using the soft-EM for mixtures of VMF distributions

“All about fish” Fish market. Museum. Fishing school in the area of the existing fish market

Η διπλωματική μου αφορά στη μελέτη του παραλιακού μετώπου της Πάτρας, το οποίο αλλάζει ριζικά μετά την μεταφορά του εμπορικού και τμήματος του επιβατικού λιμανιού της πόλης από το κέντρο στα νότια προάστια της. Αρχικά αναλύεται ολόκληρο το παραθαλάσσιο μέτωπο της πόλης και παρατίθενται προτάσεις σε επίπεδο πολεοδομικού και ευρύτερου αστικού σχεδιασμού με στόχο την ανάκτηση της επαφής της πόλης (και επομένως και των πολιτών) και της θάλασσας - μιας σχέση που είχε υποστεί ρήξη τα τελευταία σαράντα χρόνια με την περίφραξη του λιμένος. Εν συνεχεία επιλέγεται το τμήμα του παραλιακού μετώπου που ανήκει στην περιοχή της ιχθυόσκαλας Πατρών (μεταξύ των οδών Γούναρη και Παπαφλέσσα), στο οποίο και προτείνεται η δημιουργία ενός συνόλου κτηριακών εγκαταστάσεων και ενός παραλιακού πάρκου. Πιο συγκεκριμένα, σχεδιάζεται η επέκταση της υφιστάμενης ιχθυόσκαλας και με αφορμή αυτή ένα σύγχρονο κέντρο ανάδειξης της αλιείας και του αλιευτικού εμπορίου. Γι’ αυτό επιλέγεται η τοποθέτηση δίπλα στην ιχθυόσκαλα μιας μεγάλης αγοράς, με κυρίαρχη την ψαραγορά, μιας σειράς εστιατορίων τύπου open cuisine, μιας σχολής αλιείας για επαγγελματίες και ερασιτέχνες αλιείς και ενός μουσείου αλιείας και αλιευμάτων.My dissertation focuses on the study of Patra’s coast side, which radically changed after the transfer of the commercial and civil port facilities and services from downtown to the city’s southern suburbs. Initially, we analyze Patra’s coast line in order to develop and propose a totally new urban design project that will reconnect citizens with the sea line since the port security boundaries diminished after fourty years of presence. We also study the part of the coast side in which operates Patra’s fish market (among Gounari and Papaflessa str.) where we propose the development of a block of buildings and a park. In particular, we upgrade the current fish market facilities in order to create a modern fish market center, in which operate open cuisine restaurants, a fishing school (for professionals and amateurs) and a fishing museum.Τριαντάφυλλος Σ. Μαμμάση

Spherical Statistics and Spatial Correlation for Multielement Antenna Systems

The well-known assumption of horizontal plane wave propagation is investigated and evidence suggests that elevation plays a crucial role in defining the spatial correlation between signals on adjacent antenna array elements. To augment previously published studies, an explicit relationship between the distribution of scatterers in three-dimensional (3D) space and the spatial correlation is formulated. A novel approach is taken for modeling of the distribution of scatterers in space. More specifically, the distribution of scatterers is modeled by the 3D von Mises-Fisher (vMF) distribution. In addition, a closed-form expression is derived for the harmonic coefficients of the vMF density. The main derivation expresses the spherical harmonic coefficients associated with an arbitrary mean direction on the sphere. Further, a closed-form expression for the spatial correlation function (SCF) is derived, based on the spherical harmonic expansion (SHE) of plane waves as well as the harmonic coefficients of the expanded vMF density. A novel approach is proposed for including the effect of directional antenna responses in the SCF. Finally, the SCF is evaluated under the existence of multiple scatterer clusters in the channel. </p

Spatial Fading Correlation model using mixtures of Von Mises Fisher distributions

In this paper new expressions for the Spatial Fading Correlation (SFC) functions of Antenna Arrays (AA) in a 3-dimensional (3D) multipath channel are derived. In particular the Uniform Circular Array (UCA) antenna topology is considered. The derivation of the novel SFC function uses a Probability Density Function (PDF) originating from the field of directional statistics, the Von Mises Fisher (VMF) PDF. In particular the novel SFC function is based on the concept of mixture modeling and hence uses a mixture of VMF distributions. Since the SFC function is dependent on the Angle of Arrival (AoA) as well as the power of each cluster, the more appropriate power azimuth colatitude spectrum term has been used. The choice of distribution is validated with the use of Multiple Input Multiple Output (MIMO) experimental data that was obtained in an outdoor drive test campaign in Germany. A mixture can be composed of any number of clusters and this is mainly dependent on the clutter type encountered in the propagation environment. The parameters of the individual clusters within the mixture are derived and an estimation of those parameters is achieved using the soft-Expectation Maximization (EM) algorithm. The results indicate that the proposed model fits well with the MIMO data

Modeling scatterer clusters in 3D using spherical statistics for 4G communications

Paper describes the modelling of scatterer clusters in 3D using spherical statistics for 4G communications