scholarly journals Μοντελοποίηση και ανάπτυξη ετερογενών κινητών δικτύων οχήματος-προς-όχημα (Vehicle-to-Vehicle) και οχήματος-προς-υποδομή (Vehicle-to-Infrastructure) με έμφαση σε δύσκολα περιβάλλοντα μετάδοσης

2018 ◽  
Author(s):  
Μιχαήλ Χαρίτος
Keyword(s):  
Ray Tracing ◽  
Break Point ◽  
Vertical Handover ◽  
Base Station ◽  
Ieee 802.11P ◽  
Single Output ◽  
Vehicle To Vehicle ◽  
Multiple Input ◽  
Single Input ◽  
Vehicle To Infrastructure

Η παρούσα διατριβή έχει ως θέμα τη μοντελοποίηση και ανάπτυξη ετερογενών κινητών δικτύων οχήματος-προς-όχημα (Vehicle to-Vehicle) και οχήματος-προς-υποδομή (Vehicle-to-Infrastructure) με έμφαση σε δύσκολα περιβάλλοντα μετάδοσης. Ειδικότερα η διατριβή προσέγγισε το πρόβλημα της έλλειψης αξιοπιστίας των εξομοιώσεων λόγω της διαφοροποίησης τους σε σύγκριση με πειραματικές μετρήσεις και ειδικότερα κατά την περίπτωση ασύρματης μετάδοσης εντός σήραγγας για εφαρμογές επιτήρησης εντός κινούμενων κόμβων (τρένο-οχήματα) με χρήση ετερογενών δικτύων. Για το σκοπό αυτό μελετήθηκαν με μεγάλη λεπτομέρεια μοντέλα καναλιού για την εξεύρεση του πλέον κατάλληλου. Ο πρώτος κατά σειρά στόχος της διατριβής όπως προαναφέρθηκε είναι η επιλογή/ανάπτυξη ενός αντιπροσωπευτικού μοντέλου καναλιού, για ασύρματα κινούμενα δίκτυα. Πιο συγκεκριμμένα, προτάθηκε με βάση πειραματικές μετρήσεις και επιλέχθηκε μοντέλο ασύρματου καναλιού για την περιοχή συχνοτήτων 5.4-5.9 GHz σε περιβάλλοντα σήραγγας αμαξοστοιχίας και αυτοκινητοδρόμου. Ο δεύτερος βασικός στόχος της παρούσας διατριβής ήταν ο σχεδιασμός και η αναπτύξη ενός αλγόριθμου μεταπομπής για τη βελτιστοποίηση των επιδόσεων σε συνθήκες μετάδοσης-λήψης οχημάτων – συρμών τρένων τα οποία κινούνται σε αντιπαράλληλες τροχίες εντός σήραγγας, κατά τη διαδικασία του WiMAX FBSS (Fast Base Station Switching) Handover και η σύγκρισή του με τον αντίστοχο Vertical Handover (VHO). O επόμενος στόχος ήταν ο σχεδιασμός ενός αλγόριθμου που στοχεύει στην βελτιστοποίηση του QoS του ασύρματου καναλιού κατά την περίπτωση ενός ασύρματου κινούμενου ετερογενούς (HetNet) IEEE 802.11p - LTE δικτύου οχημάτων με χρήση των τεχνικών SISO (single-input & single-output)και MIMO (multiple-input & multiple-output) εντός προαστιακού περιβάλλοντος. Ο αλγόριθμος περιλαμβάνει τη δυναμική ομαδοποίηση των οχημάτων σε clusters καθώς και την επιλογή Cluster Header (CH) και του αντίστοιχου Gateway για το Het-Net IEEE 802.11p – LTE. Για την πληρέστερη τεκμηρίωση των αποτελεσμάτων συγκρίθηκαν τα αποτελέσματα με αντίστοιχους Handover αλγόριθμους βασισμένους στην τεχνική του Clustering και αντιστοίχως για διαφορετική πυκνότητα και ταχύτητα οχημάτων. Για το σκοπό αυτό ο προτεινόμενος Handover αλγόριθμος εξομοιώθηκε μέσω της βιβλιοθήκης Veins του εξομοιωτή OMNeT++, με τη χρήση του SUMO – (Simulation of Urban Mοbility) εξομοιωτή. Μια ξεχωριστή συνεισφορά της διατριβής αποτέλεσε η ανάπτυξη της καινοτόμου μεθόδου του Virtual Drive testing μέσω της προσομοίωσης ενός αυτοκινούμενου LTE προτύπου για μια προεπιλεγμένη διαδρομή, με τη χρήση ενός LTE base station emulator, ενός Channel emulator, ενός RayTracing tool και μιας φορητής συσκευής σε ρόλο LTE κινούμενου κόμβου. Απώτερος στόχος του Virtual Drive testing είναι η χαρτογράφηση του LTE δικτύου ενός κινούμενου οχήματος σε μια προεπιλεγμένη περιοχή ενδιαφέροντος και η ρεαλιστική απεικόνιση των συνθηκών μετάδοσης με τη χρήση ενός Ray Tracing μοντέλου καναλιού σε προαστικό περιβάλλον. Τέλος, η έρευνα επεκτάθηκε στο σχεδιασμό και την εξομοίωση του προτεινόμενου Break-Point-PathLoss μοντέλου καναλιού σε περιβάλλον σήραγγας και εν συνεχεία εφαρμόστηκε σε ετερογενή WiMAX-WLAN δίκτυα. Με τη χρήση του προτεινόμενου Break-Point-PathLoss μοντέλου καναλιού ο χρήστης δύναται πλέον να εξομοιώσει με ακρίβεια οποιοδήποτε ασύρματο δίκτυο στον εξομοιωτή OMNeT++ και να παράξει αξιόπιστα αποτελέσματα για εφαρμογές ασύρματων δικτύων σε σήραγγα αρκεί να γνωρίζει τις γεωμετρικές διαστάσεις της.

scholarly journals Investigating and Modeling of Cooperative Vehicle-to-Vehicle Safety Stopping Distance

2021 ◽  
Vol 13 (3) ◽  
pp. 68
Author(s):  
Steven Knowles Flanagan ◽  
Zuoyin Tang ◽  
Jianhua He ◽  
Irfan Yusoff
Keyword(s):  
High Reliability ◽  
Base Station ◽  
Ieee 802.11P ◽  
Packet Losses ◽  
The Road ◽  
V2v Communication ◽  
Stopping Distance ◽  
Vehicle To Vehicle ◽  
V2v Communications ◽  
On The Road

Dedicated Short-Range Communication (DSRC) or IEEE 802.11p/OCB (Out of the Context of a Base-station) is widely considered to be a primary technology for Vehicle-to-Vehicle (V2V) communication, and it is aimed toward increasing the safety of users on the road by sharing information between one another. The requirements of DSRC are to maintain real-time communication with low latency and high reliability. In this paper, we investigate how communication can be used to improve stopping distance performance based on fieldwork results. In addition, we assess the impacts of reduced reliability, in terms of distance independent, distance dependent and density-based consecutive packet losses. A model is developed based on empirical measurements results depending on distance, data rate, and traveling speed. With this model, it is shown that cooperative V2V communications can effectively reduce reaction time and increase safety stop distance, and highlight the importance of high reliability. The obtained results can be further used for the design of cooperative V2V-based driving and safety applications.

Estimation Design Using Youla Parametrization With Automotive Applications

2018 ◽  
Vol 140 (8) ◽  
Author(s):  
Francis Assadian ◽  
Alex K. Beckerman ◽  
Jose Velazquez Alcantar
Keyword(s):  
Kalman Filtering ◽  
Feedback Stabilization ◽  
Estimation Technique ◽  
Single Input Single Output ◽  
Normal Forces ◽  
Single Output ◽  
Multiple Input ◽  
Single Input ◽  
Established Technique ◽  
Better Than

Youla parametrization is a well-established technique in deriving single-input single-output (SISO) and, to a lesser extent, multiple-input multiple-ouput (MIMO) controllers (Youla, D., Bongiorno, J. J., Jr., and Lu, C., 1974, “Singleloop Feedback-Stabilization of Linear Multivariable Dynamical Plants,” Automatica, 10(2), pp. 159–173). However, the utility of this methodology in estimation design, specifically in the framework of controller output observer (COO) (Ozkan, B., Margolis, D., and Pengov, M., 2008, “The Controller Output Observer: Estimation of Vehicle Tire Cornering and Normal Forces,” ASME J. Dyn. Syst., Meas., Control, 130(6), p. 061002), is not established. The fundamental question to be answered is as follows: is it possible to design a deterministic estimation technique using Youla paramertization with the same robust performance, or better, than well-established stochastic estimation techniques such as Kalman filtering? To prove this point, at this stage, a comparative analysis between Youla parametrization in estimation and Kalman filtering is performed through simulations only. In this paper, we provide an overview of Youla parametrization for both control and estimation design. We develop a deterministic SISO and MIMO Youla estimation technique in the framework of COO, and we investigate the utility of this method for two applications in the automotive domain.

scholarly journals Cognitive-Femtocell Based Resource Allocation in Macrocell Network

2021 ◽  
Author(s):  
Joydev Ghosh
Keyword(s):  
Base Station ◽  
Base Stations ◽  
Network Coverage ◽  
Femtocell Networks ◽  
Single Input Single Output ◽  
Single Output ◽  
Efficiency Measures ◽  
Input Multiple Output ◽  
Single Input ◽  
Cognitive Femtocell

<div>In this paper, we articulate the network coverage issues for both Femto Users (FUs) and Macro Users (MUs) located at cell edges. The cognitive-femtocell networks functioning under the vicinity of a macrocell frontier where the parameters such as pathloss, shadowing, Rayleigh fading have considered into the system model. The users, located at network border are positioned far apart from the Macro Base Station (MBS). This can be treated as the underprivileged users. The underprivileged users are to be facilitated by the femto cell base stations to provide uninterrupted QoS. We present on the overall outage probability of Single Input single Output (SISO) users and Single Input Multiple Output (SIMO) users, respectively, by taking several circumstantial components such as such as probability density function (PDF), location gap between base stations (BSs) and users, intra-tier interference and inter-tier interference into account. Further, evaluation has been extended by considering network throughput as the efficiency measures based on the sub-carrier and the power allotment in the dual tier network.</div>

scholarly journals On the Trade-Off between Energy Efficiency and Spectral Efficiency in RIS-Aided Multi-User MISO Downlink

Electronics ◽  
2021 ◽  
Vol 10 (11) ◽  
pp. 1307
Author(s):  
Meng Zhang ◽  
Le Tan ◽  
Kelin Huang ◽  
Li You
Keyword(s):  
Energy Efficiency ◽  
Spectral Efficiency ◽  
Low Cost ◽  
Base Station ◽  
Trade Off ◽  
Optimization Framework ◽  
Single Output ◽  
Multiple Input ◽  
Fast Convergence Rate ◽  
Simulation Results

As reconfigurable intelligent surfaces (RISs) have been gradually brought to reality, a large amount of research has been conducted to investigate the immense benefits of RISs. That is because RISs enable us to artificially direct the radio wave propagating through the environment at a relatively low cost. This paper investigates the trade-off between spectral efficiency (SE) and energy efficiency (EE) in the RIS-aided multi-user multiple-input single-output downlink. We develop an optimization framework for designing the transmitting precoding at the base station and the phase shift values at the RIS to balance the EE-SE trade-off. The proposed iterative optimization framework for the design includes quadratic transform, alternating optimization, and weighted minimization mean-square error conversion. Simulation results illustrate our optimization framework algorithm exhibits effectiveness and a fast convergence rate.

scholarly journals Deployment of a Software to Simulate Control Systems in the State-Space

Electronics ◽  
2019 ◽  
Vol 8 (11) ◽  
pp. 1205 ◽  
Author(s):  
María Flores ◽  
Luis Payá ◽  
David Valiente ◽  
Julio Gallego ◽  
Oscar Reinoso
Keyword(s):  
State Feedback ◽  
Graphical Representation ◽  
Simulation Software ◽  
State Feedback Control ◽  
Physical Systems ◽  
Virtual Plant ◽  
Single Output ◽  
Multiple Input ◽  
Integral Controller ◽  
Single Input

In this work, we present a simulation software that permits designing and testing several types of controllers based on both classical and modern control theory. It has been created using Easy JavaScript Simulations, since this software permits implementing interactive simulations of physical systems in a quick and intuitive way. This laboratory contains a SISO (Single-Input and Single-Output) and a MIMO (Multiple-Input and Multiple-Output) plant, which are hydraulic and nonlinear, thus the linear model (linearized equations) and the original model (nonlinerized equations) have been implemented. The user can choose any of these physical systems and they have the options to control them using either continuous-time or discrete-time controllers. All parameters of the plant are fully configurable by the user. After that, the controller can be designed and tested. This simulation software offers several configurations: (a) PID (Proportional, Integral and Derivative controller); (b) state feedback; (c) observer and state feedback; and (d) integral controller, observer and state feedback control. The evolution of the controlled system is visualized using an animation of the virtual plant and a graphical representation of the evolution of the most important variables. In this paper, the steps for the implementation of this simulation software are detailed.

Novel Modeling Method for Networked Control Systems with Packet Disordering

2012 ◽  
Vol 433-440 ◽  
pp. 2491-2497
Author(s):  
Shi Qian Han ◽  
Jin Na Li ◽  
Mao Quan Wu
Keyword(s):  
Control Systems ◽  
Packet Loss ◽  
Networked Control Systems ◽  
Modeling Method ◽  
Networked Control ◽  
The Novel ◽  
Single Output ◽  
Multiple Input ◽  
Single Input ◽  
Novel Model

This paper focuses on the modeling problem for networked control systems subject to packet disordering. Both network-induced delay and packet loss are taken into consideration. In constructing the model, we first present the novel model for single input and single output (SISO) networked control systems based on the displacement values of packets in terms of switched systems theory, and then which can be extended to the case in multiple input and multiple output (MIMO) networked control systems with packet disordering. The merits or advantages of the modeling method proposed include describing fully the phenomenon of packet disordering, guaranteeing the newest signals to be executed and extensive applicability.

scholarly journals Cognitive-Femtocell Based Resource Allocation in Macrocell Network

2021 ◽  
Author(s):  
Joydev Ghosh
Keyword(s):  
Base Station ◽  
Base Stations ◽  
Network Coverage ◽  
Femtocell Networks ◽  
Single Input Single Output ◽  
Single Output ◽  
Efficiency Measures ◽  
Input Multiple Output ◽  
Single Input ◽  
Cognitive Femtocell

<div>In this paper, we articulate the network coverage issues for both Femto Users (FUs) and Macro Users (MUs) located at cell edges. The cognitive-femtocell networks functioning under the vicinity of a macrocell frontier where the parameters such as pathloss, shadowing, Rayleigh fading have considered into the system model. The users, located at network border are positioned far apart from the Macro Base Station (MBS). This can be treated as the underprivileged users. The underprivileged users are to be facilitated by the femto cell base stations to provide uninterrupted QoS. We present on the overall outage probability of Single Input single Output (SISO) users and Single Input Multiple Output (SIMO) users, respectively, by taking several circumstantial components such as such as probability density function (PDF), location gap between base stations (BSs) and users, intra-tier interference and inter-tier interference into account. Further, evaluation has been extended by considering network throughput as the efficiency measures based on the sub-carrier and the power allotment in the dual tier network.</div>

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