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Performance of a Non-Orthogonal Multiple Access System with Full-duplex Relaying over Nakagami-m FadingErpina, Rahul Chowdary, Gopireddy, Viswakanth Reddy January 2021 (has links)
In our thesis work, we analyze the performance analysis of a power domain NonOrthogonal Multiple Access (NOMA) system in which the closer user acts as fullduplex relaying to forward the signal to farther user. Because Nakagami-m distribution is a generalized case including the two common fading distributions as specialcases: Rayleigh distribution (m=1), Rician distribution (m>1). We assume that thesystem experiences Nakagami-m fading. Then, we have to analyze outage probabilityof NOMA system. Numerical results are provided for outage probability to show theeffect of system parameters on the performance of the NOMA system in full duplexrelaying over Nakagami-m fading.
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Estatisticas de ordem superior para canais de desvanecimento Weibull e Nakagami-m / Higher order statistics for Nakagami-m and Weibull fading channelsCosta, Daniel Benevides da 28 April 2006 (has links)
Orientador: Michel Daoud Yacoub / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Eletrica e de Computação / Made available in DSpace on 2018-08-06T06:51:34Z (GMT). No. of bitstreams: 1
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Previous issue date: 2006 / Resumo: Esta dissertação provê uma análise das estatísticas de ordem superior para canais de desvanecimento WeibuII e Nakagami-m. Considerando canais de desvanecimento WeibulI, devido à ausência de um modelo físico para tais canais, estatísticas conjuntas de duas variáveis WeibuII correlacionadas foram obtidas em forma fechada e em função de parâmetros físicos bem conhecidos. Outra estatística encontrada foi a taxa de cruzamento de nível e a duração média de desvanecimento usando diversidade com dois ramos para canais WeibuII correlacionados, desbalanceados e não-idênticos. Além disso, uma caracterização do comportamento do processo de fase e de sua derivada temporal para sinais WeibuII foi realizada. Analisando canais de desvanecimento Nakagami-m, uma expressão simples e em forma fechada para a taxa de cruzamento de fase generalizada foi obtida. Resultados de simulação completamente validaram a formulação proposta. Além disso, novas estatísticas em forma fechada para a envoltória, para as componentes em fase e em quadratura, para a fase e para suas respectivas derivadas temporais foram obtidas / Abstract: This dissertation provides an analysis of the higher order statistics for WeibuII and Nakagami-m fading channels. Conceming WeibuII fading channels, due to the absence of a fading model related of such channels, joint statistics for two correlated WeibuII variates were obtained in cIosed-form and in terms of welI-known physical parameters. Other statistics found were the levei crossing rate and the average fade duration for unbalanced, non-identical, correlated WeibuII channels operating over two branches of diversity. Furthermore, a characterization of the behaviour of the phase process and its time derivative for WeibuII signals was accomplish. Conceming Nakagami-m fading channeIs, a simple and cIosed-form expression for the generalized phase crossing rate was obtained. Results of simulation thoroughly validated the formulation proposed. Moreover, new cIosed-form statistics for the envelope, for the in-phase and quadrature components, for the phase and its respective time derivative were derived. / Mestrado / Telecomunicações e Telemática / Mestre em Engenharia Elétrica
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Μέθοδοι και τεχνικές βελτιστοποίησης της απόδοσης των ψηφιακών ασύρματων συστημάτων λειτουργούντων σε περιβάλλον με διαλείψεις / Methods and techniques for the performance evaluation of digital wireless telecommunication systems operating over fading channelsΖώγας, Δημήτριος 25 June 2007 (has links)
Η χρήση διαφορισμού σε συστήματα κινητών επικοινωνιών είναι μία ευρέως χρησιμοποιούμενη τεχνική για την καταπολέμηση των διαλείψεων που παρατηρούνται στις ραδιοζεύξεις. Στην παρούσα διατριβή παρουσιάζονται διάφοροι τρόποι και τεχνικές για την μελέτη της απόδοσης συστημάτων που κάνουν χρήση διαφορισμού στον δέκτη. Οι τεχνικές διαφορισμού που μελετώνται είναι ο διαφορισμός ίσου κέρδους (equal-gain combining) και ο διαφορισμός επιλογής (selection combining). Επιπλέον, στα πλαίσια της διατριβής αυτής, υποθέτουμε ότι ο δέκτης λειτουργεί σε κανάλια μη-επιλεκτικών συχνοτήτων με βραδείες διαλείψεις (flat and slow fading channels), ενώ το εκπεμπόμενο σήμα υφίσταται διαλείψεις κατά Rayleigh, Nakagami-m, Rice ή Hoyt. Αποδεικνύεται ότι η απόδοση του συστήματος στο οποίο ο δέκτης κάνει χρήση διαφορισμού εξαρτάται σε μεγάλο βαθμό από:
• τη συσχέτιση μεταξύ των καναλιών διαφορισμού και
• τη διαφορά της ισχύος μεταξύ των καναλιών διαφορισμού. Για να μελετηθεί η απόδοση ενός ΔΕ που λειτουργεί σε συσχετισμένα Nakagami-m κανάλια παρουσιάζεται παρουσιάζονται για πρώτη φορά σε κλειστή μορφή η συνάρτηση πυκνότητας πιθανότητας (ΣΠΠ) Nakagami-m μεταβλητών με εκθετική συσχέτιση, ενώ η αντίστοιχη συνάρτηση αθροιστικής κατανομής (ΣΑΚ) που προκύπτει έχει τη μορφή πολλαπλών άπειρων αθροισμάτων. / Diversity reception has been successfully used in wireless communications systems to mitigate the negative effect of channel fading. This thesis deals with the performance analysis of wireless systems employing receiver diversity. The diversity schemes studied are selection combining (SC) and equal-gain combining (EGC). We assume that the receiver operates in flat and slow fading channels and that the signal undergoes Rayleigh, Nakagami-m, Rice or Hoyt fading. As it will be shown, the performance of the diversity system depends greatly on:
• the correlation among the diversity branches,
• the average power imbalance of the received signals In order to study the performance of a SC receiver operating in correlated Nakagami-m fading channels, we first present a statistical analysis of correlated Nakagami-m random variables (rvs). The probability density function (pdf) of exponentially correlated Nakagami-m rvs is presented in closed-form, while the corresponding cumulative distribution function (cdf) has the form of multiple converging infinite series. Furthermore, bounds for the truncation of the infinite series.
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