Search results for "5(52)"
showing 10 items of 145 documents
Performance analysis of wideband sum-of-cisoids-based channel simulators with respect to the bit error probability of DPSK OFDM Systems
2009
In this paper, we analyze the performance of a wideband sum-of-cisoids (SOC) channel simulator w.r.t. the bit error probability (BEP) of differential phase-shift keying (DPSK) orthogonal frequency division multiplexing (OFDM) systems. Analytical BEP expressions are derived for coherent and non- coherent DPSK OFDM simulation systems in the presence of a wideband SOC channel simulator. We also study the degradations of the BEP introduced by an imperfect channel simulator. Using the deviation of the BEP as an appropriate measure, we evaluate the performance of three parameter computation methods, known as the method of exact Doppler spread (MEDS), the randomized MEDS (R-MEDS), and the Monte Ca…
The Riemann sum method for the design of sum-of-cisoids simulators for Rayleigh fading channels in non-isotropic scattering environments
2009
©2009 IEEE. Personal use of this material is permitted. However, permission to reprint/republish this material for advertising or promotional purposes or for creating new collective works for resale or redistribution to servers or lists, or to reuse any copyrighted component of this work in other works must be obtained from the IEEE. Article also available from publisher: http://dx.doi.org/10.1109/ICUMT.2009.5345371 In this paper, we introduce the Riemann sum method (RSM) as an effective tool for the design of sum-of-cisoids (SOC) simulators for narrowband mobile Rayleigh fading channels under non-isotropic scattering conditions. We show that the RSM results in an excellent approximation of…
Modeling and Performance Analysis of Energy Efficiency Binary Power Control in MIMO-OFDM Wireless Communication Systems
2011
Published version of an article in the journal:International Journal of Distributed Sensor Networks. Also available from Hindawi Publishing: http://dx.doi.org/10.1155/2011/946258 The energy efficiency optimization of the binary power control scheme for MIMO-OFDM wireless communication systems is formulated, and then a global optimization solution of power allocation is derived. Furthermore, a new energy efficiency binary power control (EEBPC) algorithm is designed to improve the energy efficiency of MIMO-OFDM wireless communication systems. Simulation results show that the EEBPC algorithm has better energy efficiency and spectrum efficiency than the average power control algorithm in MIMO-O…
An intelligent architecture for service provisioning in pervasive environments
2011
Accepted version of an article from the conference: 2011 International Symposium on Innovations in Intelligent Systems and Applications (INISTA). Definitive published version available from IEEE: http://dx.doi.org/10.1109/INISTA.2011.5946134 The vision of pervasive environments is being realized more than ever with the proliferation of services and computing resources located in our surrounding environments. Identifying those services that deserve the attention of the user is becoming an increasingly-challenging task. In this paper, we present an adaptive multi-criteria decision making mechanism for recommending relevant services to the mobile user. In this context Relevance is determined b…
Broadband wireless communication systems: Channel modeling and system performance analysis
2011
Ph.D. Thesis The University of Agder, Faculty of Engineering and Science Wideband channel modeling, which can accurately describe the most important characteristics of wideband mobile fading channels, is essential for the design, evaluation, and optimization of broadband wireless communication systems. In the field of wideband channel modeling, the tradeoff between the prediction accuracy and simulation efficiency has to be taken into account. On one hand, channel models should be as accurate as possible. On the other hand, channel models are supposed to be simple and easy to put into use. There are several commonly used approaches to channel modeling, e.g., measurement-based channel modeli…
A Study of the Influence of Shadowing on the Statistical Properties of the Capacity of Mobile Radio Channels
2008
Article from the journal: Wireless Personal Communications The original publication is available at www.springerlink.com : http://dx.doi.org/10.1007/s11277-008-9545-7 This paper studies the influence of shadowing on the statistical properties of the channel capacity. The problem is addressed by using a Suzuki process as an appropriate statistical channel model for land mobile terrestrial channels. Using this model, exact solutions for the probability density function (PDF), cumulative distribution function (CDF), level-crossing rate (LCR), and average duration of fades (ADF) of the channel capacity are derived. The results are studied for different levels of shadowing, corresponding to diff…
A novel traffic splitting policy for performance improvement in wireless mesh networks
2009
©2009 IEEE. Personal use of this material is permitted. However, permission to reprint/republish this material for advertising or promotional purposes or for creating new collective works for resale or redistribution to servers or lists, or to reuse any copyrighted component of this work in other works must be obtained from the IEEE. Article also available from publisher: http://dx.doi.org/10.1109/EW.2009.5357990 Wireless mesh networks are expected to play an important role in the next-generation wireless communication systems as it can provide wide coverage and scalable broadband Internet access services. However, as more traffic is injected into the network it may lead to throughput degra…
A system-level power saving approach for cellular networks with microcells/picocells
2011
Accepted version of an article from the book: 2011 2nd International Conference on Wireless Communication, Vehicular Technology, Information Theory and Aerospace & Electronic Systems Technology (Wireless VITAE). Published version available from IEEE: http://dx.doi.org/10.1109/WIRELESSVITAE.2011.5940872 Network power consumption reduction has recently become an active research topic. In this paper, we propose a novel approach to save power consumption of a three-cell microcellular network. When the traffic load in the middle cell is low, it can be switched-off and its users are covered. This is enabled by increasing the transmission power of one sector antenna in the two neighboring cells. N…
Greedy versus Dynamic Channel Aggregation Strategy in CRNs: Markov Models and Performance Evaluation
2011
Publishes version of a paper from the book: Networking 2011 Workshops. Also available f rom the publisher on SpringLink:http://dx.doi.org/10.1007/978-3-642-23041-7_3 In cognitive radio networks, channel aggregation techniques which aggregate several channels together as one channel have been proposed in many MAC protocols. In this paper, we consider elastic data traffic and spectrum adaptation for channel aggregation, and propose two new strategies named as Greedy and Dynamic respectively. The performance of channel aggregation represented by these strategies is evaluated using continuous time Markov chain models. Moreover, simulation results based on various traffic distributions are utili…
Medium access in cognitive radio networks: From single hop to multiple hops
2012
Doktorgradsavhandling i informasjons- og kommunikasjonsteknologi, Universitetet i Agder, Grimstad, 2012 If channel assembling is enabled, this technique can be utilized for potential performance improvement in CRNs. Two use cases are envisaged for channel assembling. In the first use case, the system can accommodate parallel SU services in multiple channels, while in the second use case, the system allows only one SU service at a time. In the use case where parallel SU services are allowed, various channel assembling strategies are proposed and modeled in order to investigate their performance and to acquire better comprehension of the behavior of CRNs with channel assembling. Moreover, the…