96 research outputs found
Review on Radio Resource Allocation Optimization in LTE/LTE-Advanced using Game Theory
Recently, there has been a growing trend toward ap-plying game theory (GT) to various engineering fields in order to solve optimization problems with different competing entities/con-tributors/players. Researches in the fourth generation (4G) wireless network field also exploited this advanced theory to overcome long term evolution (LTE) challenges such as resource allocation, which is one of the most important research topics. In fact, an efficient de-sign of resource allocation schemes is the key to higher performance. However, the standard does not specify the optimization approach to execute the radio resource management and therefore it was left open for studies. This paper presents a survey of the existing game theory based solution for 4G-LTE radio resource allocation problem and its optimization
DR9.3 Final report of the JRRM and ASM activities
Deliverable del projecte europeu NEWCOM++This deliverable provides the final report with the summary of the activities carried out in NEWCOM++ WPR9, with a particular focus on those obtained during the last year. They address on the one hand RRM and JRRM strategies in heterogeneous scenarios and, on the other hand, spectrum management and opportunistic spectrum access to achieve an efficient spectrum usage. Main outcomes of the workpackage as well as integration indicators are also summarised.Postprint (published version
Mobile and Wireless Communications
Mobile and Wireless Communications have been one of the major revolutions of the late twentieth century. We are witnessing a very fast growth in these technologies where mobile and wireless communications have become so ubiquitous in our society and indispensable for our daily lives. The relentless demand for higher data rates with better quality of services to comply with state-of-the art applications has revolutionized the wireless communication field and led to the emergence of new technologies such as Bluetooth, WiFi, Wimax, Ultra wideband, OFDMA. Moreover, the market tendency confirms that this revolution is not ready to stop in the foreseen future. Mobile and wireless communications applications cover diverse areas including entertainment, industrialist, biomedical, medicine, safety and security, and others, which definitely are improving our daily life. Wireless communication network is a multidisciplinary field addressing different aspects raging from theoretical analysis, system architecture design, and hardware and software implementations. While different new applications are requiring higher data rates and better quality of service and prolonging the mobile battery life, new development and advanced research studies and systems and circuits designs are necessary to keep pace with the market requirements. This book covers the most advanced research and development topics in mobile and wireless communication networks. It is divided into two parts with a total of thirty-four stand-alone chapters covering various areas of wireless communications of special topics including: physical layer and network layer, access methods and scheduling, techniques and technologies, antenna and amplifier design, integrated circuit design, applications and systems. These chapters present advanced novel and cutting-edge results and development related to wireless communication offering the readers the opportunity to enrich their knowledge in specific topics as well as to explore the whole field of rapidly emerging mobile and wireless networks. We hope that this book will be useful for students, researchers and practitioners in their research studies
A Scheduling and Resource Allocation Algorithm for LTE Networks Using Tree Structures
Το σύστημα LTE σχεδιάστηκε από τη 3GPP με στόχο την ικανοποίηση των
ολοένααυξανόμενων αναγκών για ασύρματη ευρυζωνική πρόσβαση. Τεχνικές όπως το
σχήμα πολλαπλής πρόσβασης OFDMA, το MIMOκαι η Προσαρμοστική Διαμόρφωση και
Κωδικοποίηση υιοθετήθηκαν προκειμένου να αυξήσουν τους επιτεύξιμους
ρυθμούςμετάδοσης και να βελτιώσουν τη φασματική απόδοση. Ωστόσο, απαιτείται η
ανάπτυξη εξελιγμένων αλγορίθμωνχρονοπρογραμματισμού προκειμένου να αξιοποιηθεί
η πλήρης δυναμική αυτών των τεχνικών. Παρά το γεγονός ότι η
3GPPέχειπροτυποποιήσει πλήρως τη σηματοδοσία ελέγχου που απαιτείται για την
εκτέλεση του χρονοπρογραμματισμού, οι αλγόριθμοι πουχρειάζεται να εκτελεστούν
προκειμένου να ληφθούν αποδοτικές αποφάσεις έχουν αφεθεί στους κατασκευαστές
για υλοποίηση.Ωςεκ τούτου, σημαντική ερευνητική προσπάθεια έχει καταβληθεί προς
αυτή την κατεύθυνση και έχουν προταθεί αρκετοίαλγόριθμοιχρονοπρογραμματισμού.
Το κύριο συμπέρασμα που εξάγεται από τη μελέτη της βιβλιογραφίας είναι ότι
οχρονοπρογραμματισμόςσε ένα σύστημα πολλών φερουσών με τους περιορισμούς του
LTE αποτελεί ένα πολυδιάστατο πρόβλημα.Ανάμεσα στις πολλέςδιαστάσεις του, αυτές
που κυρίως λαμβάνονται υπόψη στους προτεινόμενους αλγορίθμους είναι
ηρυθμαπόδοση, η δικαιοσύνη και η εξασφάλιση εγγυημένης ποιότητας υπηρεσίας.Η
κύρια συμβολή της παρούσας διατριβής είναι η πρόταση ενός νέου αλγόριθμου
χρονοπρογραμματισμού και διαχείρισης πόρων ο οποίος αντιμετωπίζει τα
περισσότερα από τα θέματα που καθορίζουν τησυνολική απόδοση μίας οντότητας
χρονοπρογραμματισμού του LTE. Η πρόταση εστιάζει κυρίως στην πολυπλοκότητα
πουεισάγεται κατά τη λήψη μίας απόφασης χρονοπρογραμματισμού. Επιχειρεί δε να
επιλύσει αυτό το πρόβλημα με την εισαγωγή μίαςεξελιγμένης δενδρικής δομής η
οποία επιτρέπει την αποδοτική αποθήκευση όλων των παραμέτρων που θεωρούνται
ουσιώδεις στηδιαδικασία λήψης μίας απόφασης χρονοπρογραμματισμού. Με αυτό τον
τρόπο η οντότητα χρονοπρογραμματισμού έχει άμεσηπρόσβαση σε αυτές τις
πληροφορίες. Στην εργασία περιγράφεται ένας πλήρης αλγόριθμος προγραμματισμού
στο πεδίο τουχρόνου που αξιοποιεί αυτή τη δενδρική δομή και επιπλέον
προτείνονται δύο νέοι αλγόριθμοι κατανομής πόρων. Οι αλγόριθμοιαυτοί επίσης
αξιοποιούν κάποιες επιπρόσθετες δενδρικές
δομές οι οποίες παράγονται ύστερα από κατάλληλη προ-επεξεργασίαπου λαμβάνει
χώρα πριν τη λήψη της απόφασης χρονοπρογραμματισμού. Ο πρώτος αλγόριθμος
παρουσιάζει χαμηλήπολυπλοκότητα και ικανοποιητική απόδοση ενώ ο δεύτερος
βελτιωμένη απόδοση με το κόστος κάποιας επιπρόσθετηςπολυπλοκότητας.
Αποτελέσματα εκτεταμένων προσομοιώσεων επιβεβαιώνουν την ικανότητα του
προτεινόμενου σχήματος στηνικανοποίηση των αυστηρών απαιτήσεων του LTE σε ότι
αφορά την ποιότητα υπηρεσίας, ενώ ταυτόχρονα η απόδοση τωνπροτεινόμενων
αλγορίθμων συγκρίνεται με γνωστές τεχνικές χρονοπρογραμματισμού. Οι
προτεινόμενες λύσεις είναι εφαρμόσιμες μόνο στην περίπτωση της κατωφερούς
ζεύξης, ωστόσο η ίδια ιδέα μπορεί να προσαρμοστεί κατάλληλα για να παρέχει μία
αποδοτική λύση και στην περίπτωση της ανωφερούς ζεύξηςLong Term Evolution (LTE) has been designed by 3GPP with the target to meet the
ever increasing demands in broadband wireless access. Techniques such as OFDMA
multiple access scheme, MIMO and Adaptive Modulation and Coding (AMC) have been
adopted in order to boost the achieved data rates and improve spectral
efficiency. However, the development of sophisticated scheduling algorithms is
required so that the full potential of those techniques is exploited. Even
though 3GPP has fully standardized the control signaling required to perform
scheduling, the algorithms that need to be executed to make efficient decisions
are left to vendor implementation. Therefore significant research effort has
been dedicated to this direction and several scheduling algorithms have been
proposed. The main conclusion drawn from the study of the literature is that
scheduling in a multicarrier system with the restrictions of LTE constitutes a
multidimensional problem. Among the multiple dimensions, those that are mostly
considered in the proposed algorithms are throughput, fairness and QoS
guarantee. The main contribution of this thesis is to propose a new scheduling
algorithm that addresses most of the issues that define the overall performance
of an LTE scheduler. The proposal focuses mainly on the complexity involved in
making a scheduling decision. It attempts to resolve this issue by the
introduction of a sophisticated tree structure that enables the efficient
storage of all the parameters that are considered essential in the scheduling
decision process. Thus the scheduler can have immediate access to this
information. A full time domain scheduling algorithm that utilizes this tree
structure is described and two new resource allocation algorithms are proposed.
These algorithms also utilize some additional tree structures derived from
appropriate preprocessing actions that take place before the actual scheduling
decision. The first algorithm has low complexity and satisfactory performance
while the second has improved performance with the cost of some additional
complexity. Extensive simulation results confirm the capability of the proposed
scheme in satisfying the strict QoS requirements of LTE, while the performance
of the newly proposed algorithms is compared with well-known scheduling
techniques. The proposed solutions are applicable to the downlink case, while
the same concept may be adapted properly to provide an efficient solution for
the uplink case
Unmanned Aerial Vehicle (UAV)-Enabled Wireless Communications and Networking
The emerging massive density of human-held and machine-type nodes implies larger traffic deviatiolns in the future than we are facing today. In the future, the network will be characterized by a high degree of flexibility, allowing it to adapt smoothly, autonomously, and efficiently to the quickly changing traffic demands both in time and space. This flexibility cannot be achieved when the network’s infrastructure remains static. To this end, the topic of UAVs (unmanned aerial vehicles) have enabled wireless communications, and networking has received increased attention. As mentioned above, the network must serve a massive density of nodes that can be either human-held (user devices) or machine-type nodes (sensors). If we wish to properly serve these nodes and optimize their data, a proper wireless connection is fundamental. This can be achieved by using UAV-enabled communication and networks. This Special Issue addresses the many existing issues that still exist to allow UAV-enabled wireless communications and networking to be properly rolled out
Resource allocation and optimization techniques in wireless relay networks
Relay techniques have the potential to enhance capacity and coverage of a wireless network. Due to rapidly increasing number of smart phone subscribers and high demand for data intensive multimedia applications, the
useful radio spectrum is becoming a scarce resource. For this reason, two way relay network and cognitive radio technologies are required for better utilization of radio spectrum. Compared to the conventional one way relay
network, both the uplink and the downlink can be served simultaneously using a two way relay network. Hence the effective bandwidth efficiency is considered to be one time slot per transmission. Cognitive networks are wireless networks that consist of different types of users, a primary user (PU, the primary license holder of a spectrum band) and secondary users (SU, cognitive radios that opportunistically access the PU spectrum). The
secondary users can access the spectrum of the licensed user provided they do not harmfully affect to the primary user. In this thesis, various resource
allocation and optimization techniques have been investigated for wireless relay and cognitive radio networks
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