Дисертації з теми "Two-way channels"
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Zhong, Peng. "Coding schemes for the two-way relay channels." Thesis, McGill University, 2012. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=110709.
Повний текст джерелаDans les reseaux de transmission modernes, les relais jouent un r^ole important dans lesstrategies cooperatives. Plusieurs strategies de relai, telles que decode-forward, compressforwardet amplify-forward, ont ete proposees pour les canaux et reseaux a relais. Cependant,la capacite du canal a relai general et de tels reseaux reste toujours inconnue. Danscette these, nous proposons plusieurs strategies de relai pour dierents modeles.Dans un premier temps, nous proposons de nouvelles strategies de decode-forward partiel(PDF) pour le canal a relai bidirectionnel avec lien direct. A la dierence du decodeforwardclassique, chaque utilisateur divise son message en deux parties, mais le relai nedecode que l'une d'entre elles pour chacun. Le relai genere alors un mot de code en fonctionde ces deux parties decodees et les transmet aux deux utilisateurs. Nous proposonsune stratgie PDF a la fois pour les liaisons half- et full-duplex. Comme le montrent lesanalyses et simulations realisees, si, pour l'un des utilisateurs, le lien direct est meilleur quele lien utilisateur-relai alors que, pour l'autre utilisateur, le lien direct est plus faible, dansce cas, la strategie PDF permet d'accro^tre strictement la region des debits atteignablespar rapport a la region atteinte par le partage de temps avec la strategie decode-forwardclassique et la transmission directe, a la fois pour les liaisons half- et full-duplex.La deuxieme partie de cette these s'interesse au codage de reseau avec bruit, qui a eteaborde recemment pour les reseaux multi-sources generiques par Lim, Kim, El Gamal etChung. Cette strategie se base sur le relayage par compress-forward (CF), mais utilise troisnouvelles idees, a savoir le binning de Wyner-Ziv, le decodage simultane moins contraignantet la repetition de message. Dans cette partie, nous prenons pour exemple les canaux arelai mono- et bidirectionnels, et nous analysons l'impact de chacune de ces idees sur laregion des debits atteignables pour les reseaux a relais.Dans la troisieme partie de cette these, nous proposons deux strategies de codage quicombinent le decode-forward (DF) et le codage de reseau avec bruit (NNC), avec dierentesnuances. La premiere est une strategie combinee DF-NNC pour le canal a relai monodirectionnel,pour laquelle DF et NNC representent des cas particuliers par partage de debit,de m^eme que lencodage partiel en bloc de Markov et NNC. La deuxieme strategie combinedeux strategies DF dierentes au codage NNC en couches pour le canal a relai bidirectionnel.Les analyses et les simulations montrent que les deux strategies proposees remplacentchaque strategie individuelle et prennent pleinement avantage des strategies DF et NNC.
Li, Lun. "Blind detection with unique identification in two-way relay channels." Thesis, Wichita State University, 2011. http://hdl.handle.net/10057/5183.
Повний текст джерелаThesis (M.S.)--Wichita State University, College of Engineering, Dept. of Electrical Engineering and Computer Science.
Heindlmaier, Michael [Verfasser]. "Network Coding for Two-Way Relay Channels and Broadcast Erasure Channels with Feedback / Michael Heindlmaier." München : Verlag Dr. Hut, 2015. http://d-nb.info/1080754334/34.
Повний текст джерелаOlausson, Nathalie. "Kommunikationsverksamhet i ett föränderligt samhälle : En studie om hur Gällivare kommun bör kommunicera med sin befolkning under samhällsomvandlingen." Thesis, Umeå universitet, Institutionen för kultur- och medievetenskaper, 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-67934.
Повний текст джерелаChen, H. "Beamforming optimization for two-way relay channel." Thesis, University College London (University of London), 2014. http://discovery.ucl.ac.uk/1421150/.
Повний текст джерелаReyneke, Annerie. "Expectations on the use of Facebook for employee engagement / Annerie Reyneke." Thesis, North-West University, 2013. http://hdl.handle.net/10394/10007.
Повний текст джерелаMA (Communication Studies), North-West University, Potchefstroom Campus, 2013
Leijonklo, Lovisa. "Lägg märke till varumärket : En kvantitativ undersökning kring hur varumärket Hollister jobbar med kommunikation för att stärka sitt varumärke." Thesis, Umeå universitet, Institutionen för kultur- och medievetenskaper, 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-85118.
Повний текст джерелаSyftet med studien är att undersöka om varumärket Hollister kan etablera sig hos sin målgrupp med hjälp av kommunikation. För att uppnå syftet har följande teorier tillämpats: varumärkesbyggande, visuell kommunikation, tvåvägs-symmetrisk kommunikation samt kommunikationskanaler. Studien har genomförts genom en kvantitativ enkätundersökning på webben. Webbenkäten riktade sig till tonåringar i åldern 15-18 år som bor i Täby eller Umeå då bland annat en frågeställning har varit ”Vilken skillnad går att utläsa mellan Täby, där det finns en butik, respektive Umeå där det inte finns någon butik”. Materialet samlades in under en period på åtta dagar mellan 11-19 december 2013. Webbenkäten svarades av 90 enheter vilket innebär en svarsfrekvens på 90 procent. Resultatet av studien visade att det skiljde en del mellan städerna framförallt går det att utläsa att enheterna från Täby hade mer kännedom kring varumärkets visuella identitet samt besökt butiken i större utsträckning. Analysen visade även att varumärkesbyggande är en viktig del för att nå ut och påverka sin målgrupp och bland annat att arbetet med den visuella kommunikationen är betydelsefull.
Schedler, Stephan [Verfasser]. "Generalized Frequency Division Multiplexing in the Two-Way-Relay Channel / Stephan Schedler." Aachen : Shaker, 2016. http://d-nb.info/1120863880/34.
Повний текст джерелаXu, Ning. "Physical-Layer Network Coding for MIMO Systems." Thesis, University of North Texas, 2011. https://digital.library.unt.edu/ark:/67531/metadc68065/.
Повний текст джерелаAbdallah, Saeed. "Spectrally-efficient approaches to channel estimation for amplify-and-forward two-way relay networks." Thesis, McGill University, 2013. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=119426.
Повний текст джерелаLes réseaux à relais constituent l'une des technologies clé de la prochaine génération des systèmes de communication sans fil. Dans les réseaux à relais, la communication entre une source et une destination est assistée par des noeuds dédiés (ou relais) qui relayent lemessage de la source jusqu'à la destination. L'utilisation de relais améliore la couverture, la capacité et la fiabilité des réseaux. Les réseaux à relais bidirectionnels (two-way relay networks ou TWRNs) ont été récemment proposés et ont suscité l'intérêt de nombreux chercheurs à cause de leur grande efficacité spectrale. En particulier, les TWRNs utilisant le protocole de relayage amplifier-et-transférer (amplify-and-forward ou AF) sont attrayants à cause de leurs faibles exigences de traitement aux relais. Le bon fonctionnent des AF TWRNs nécessite une étape d'estimation précise du canal pour la suppression d'auto-interférence et pour le décodage cohérent. La plupart des travaux sur l'estimation du canal pour les AF TWRNs suivent l'approche basée sur l'entrainement, ce qui nécessite la transmission de pilotes connus des deux terminaux .Cette approche consomme de précieuses ressources de communication afin de transmettre les pilotes, ce qui compromet l'efficacité spectrale des TWRNs. L'estimation aveugle évite ce fardeau en se fiant seulement sur les données reçues. Une autre option est l'estimation semi-aveugle, une approche hybride de l'approche aveugle et de celle basée sur l'entrainement. L'objectif de cette thèse est d'examiner l'estimation aveugle et semi-aveugle du canal pour les AF TWRNs afin d'obtenir un meilleur compromi entre l'efficacité spectrale et la précision que que celui offert par l'approche basée sur l'entrainement. Dans la première partie de cette thèse, nous considérons l'estimation aveugle du canal pour des conditions d'évanouissement plat. Employant le principe du maximum de vraisemblance déterminée (deterministic maximum likelihood ou DML), nous proposons de nouveaux algorithmes pour l'estimation et la détection aveugle et conjointe du canal pour les AF TWRNs qui utilisent une signalisation à module constant. Supposant une modulation M-PSK, nous prouvons que les estimateurs proposés sont consistants et se rapprochent du vrai canal avec une grande probabilité lorsque le rapport signal sur bruit est élevé. En utilisant des simulations, nous montrons que le DML offre un meilleur compromis entre l'efficacité spectrale et la précision que l'estimateur LS employant des pilotes. Toujours en rapport avec l'évanouissement plat, la deuxième partie de cette thèse porte sur l'estimation semi-aveugle du canal. Nous établissons la CRB exacte pour l'estimation semi-aveugle du canal pour les AF TWRNs qui utilisent une constellation QAM carrée. Cette borne est basée sur la vraie fonction de vraisemblance qui tient compte des statistiques exactes des symboles de données transmis. En utilisant cette nouvelle borne, nous montrons que la complexité attribuable à l'entrainement peut être considérablement réduite en employant un estimation semi-aveugle. Afin de montrer que ces gains sont réalisables, nous concevons un algorithme semi-aveugle basé sur la méthode d'espérance maximisation (EM), et nous montrons que cet algorithme se rapproche tout près de la CRB. Dans la dernière partie de cette thèse, nous considérons l'estimation semi-aveugle pour les TWRNs qui sont basés sur l'OFDM et qui opèrent dans un environnement sélectif en fréquence. Pour faciliter l'estimation des canaux individuels, un entrainement superposé est adopté aux relais. L'algorithme semi-aveugle que nous proposons est basé sur le principe ML gaussien .Nous concevons des séquences pilotes pour les terminaux et pour les relais de façon à optimiser la performance de l'estimation. Nos simulations révèlent que la méthode proposée fournit une nette amélioration de la précision de l'estimation.
Richter, Johannes, Elke Franz, Sabrina Engelmann, Stefan Pfennig, and Eduard A. Jorswieck. "Physical Layer Security vs. Network Layer Secrecy: Who Wins on the Untrusted Two-Way Relay Channel?" Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2014. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-145086.
Повний текст джерелаRichter, Johannes, Elke Franz, Sabrina Engelmann, Stefan Pfennig, and Eduard A. Jorswieck. "Physical Layer Security vs. Network Layer Secrecy: Who Wins on the Untrusted Two-Way Relay Channel?" Technische Universität Dresden, 2013. https://tud.qucosa.de/id/qucosa%3A28133.
Повний текст джерелаPierrot, Alexandre Jean Louis J. "Coding techniques for multi-user physical layer security." Diss., Georgia Institute of Technology, 2015. http://hdl.handle.net/1853/53836.
Повний текст джерелаSmirani, Sinda. "Étude du codage réseau au niveau de la couche physique pour les canaux bidirectionnels à relais." Phd thesis, Université Paris Sud - Paris XI, 2014. http://tel.archives-ouvertes.fr/tel-00962333.
Повний текст джерела姍, 路., and Shan Lu. "Coding and decoding for multiuser communication systems." Thesis, https://doors.doshisha.ac.jp/opac/opac_link/bibid/BB12863897/?lang=0, 2014. https://doors.doshisha.ac.jp/opac/opac_link/bibid/BB12863897/?lang=0.
Повний текст джерелаCoding and decoding for multiuser communication systems are investigated. For MAAC, we propose a coding scheme of (k + 1)-ary error-correcting signature codes. We give binary and non-binary signature codes. They are the best error-correcting signature codes for MAAC, in the sense that they have highest sum rates known. For TWRC, we propose a low-complexity two-user turbo decoding scheme when turbo codes are applied in two users. The approximate decoding algorithm preserves low decoding complexity over the Gaussian TWRC, without much performance degradation.
博士(工学)
Doctor of Philosophy in Engineering
同志社大学
Doshisha University
Abadi, Tarla. "Design and performance analysis of cooperative relay systems." Thesis, University of Manchester, 2015. https://www.research.manchester.ac.uk/portal/en/theses/design-and-performance-analysis-of-cooperative-relay-systems(8edce5bc-1518-4df2-aa49-36bf5386036a).html.
Повний текст джерелаSandes, Fábio Shimabukuro. "Um estudo empírico sobre o uso do boca a boca gerado na internet como comunicação com o cliente." reponame:Repositório Institucional do FGV, 2010. http://hdl.handle.net/10438/4744.
Повний текст джерелаO impacto do boca a boca na Imagem da Marca e no julgamento de produtos (bens e serviços) tem sido estudado há tempos na disciplina de comportamento do consumidor. Com o crescimento da internet como mídia social e meio de comunicação entre consumidores e empresas, o boca a boca ganhou força junto a profissionais e pesquisadores de Marketing. Uma revisão da literatura permitiu traçar um paralelo entre o boca a boca tradicional e o eletrônico. É preciso compreender cientificamente a influência do boca a boca eletrônico no comportamento do consumidor. Para isto, foram realizados dois estudos nesta dissertação, sendo o primeiro um estudo exploratório a partir da realização de entrevistas e aplicação de questionários a consumidores, profissionais de Marketing e especialistas do assunto com o intuito de levantar percepções gerais sobre o tema. Para avaliar estatisticamente as hipóteses propostas nesta dissertação, o segundo estudo foi a realização de um experimento com 168 estudantes, contando com cinco cenários e três tipos de produtos (Vestuário, Cosméticos e Lojas Online). A variável independente foi o Comentário Postado pelo consumidor. Duas foram as variáveis dependentes: Imagem da Marca e Intenção de Compra dela. Para a mensuração da Imagem da Marca se utilizou a escala de Personalidade de Marca de Aaker (1997). No tocante à Intenção de Compra, um concurso foi elaborado para os sujeitos. No início e no final da coleta de dados, os participantes escolhiam as empresas das quais ganhariam um prêmio (vale compra), caso fossem os vencedores. Mediu-se a Intenção de Compra em função da escolha dos consumidores antes e depois do estímulo, sendo comparados, ainda, os resultados dos diferentes cenários. Constatou-se que os comentários negativos e positivos que os consumidores postam na internet têm um impacto significante na Imagem da Marca para outros consumidores nos produtos Vestuário e Loja Online. Mas não foram percebidos impactos destes comentários na Imagem da Marca no produto Cosmético e na Intenção de Compra dos outros consumidores nos três tipos de produtos testados. O Gerenciamento dos Comentários negativos (resposta da empresa a comentário postado pelo consumidor) apresentou uma redução no impacto do comentário na Imagem da Marca para os outros consumidores no produto Loja Online. Contudo, os tons alinhados com Foco Regulatório do consumidor nas respostas das empresas não provocaram diferenças significativas, contra indicando essa concepção teórica como meio de aprimorar os resultados do Gerenciamento dos Comentários. Várias implicações científicas e profissionais interessantes decorrem da pesquisa. Para o praticante, se viu que a internet 2.0 é uma mídia a ser considerada no esforço de comunicação da empresa e que ela deve ser considerada como um canal de comunicação bidirecional.
The impact of Word of Mouth Communication on Brand Image and the evaluation of products (goods and services) has been studied for some time in the discipline of consumer behavior. With the growth of the Internet as a social media and as a means of communication between consumers and enterprises, Word of Mouth has gained strength with Marketing professionals and researchers. A review of the literature draws a parallel between traditional Word of Mouth and its electronic version. It is essential to understand scientifically the influence of Electronic Word of Mouth on consumer behavior. In order to do this, two main studies were made: the first one was an exploratory stage conducted with interviews and questionnaires applied to consumers, marketers, and experts on the subject in order to raise general perceptions on the issue. The second study aims to evaluate statistically the hypotheses proposed in this work and involves an experiment applied to 168 students, considering five scenarios and three types of products (clothing, cosmetics and Online Stores). The independent variable was the Comment Posted by the consumer on the internet. Two were the dependent variables: Brand Image and Purchase Intention. To measure Brand Image, the scale "The Brand Personality" by Aaker (1997) was used. To measure Purchase Intention subjects participated in a contest where they chose, at the beginning and end of data collection, the companies from which they would gain a gift certificate, if they won the contest. Purchase Intention was measured depending on the choice of consumers before and after the stimulus, and compared also the results of different scenarios. It was found that the positive and negative comments that consumers posted on the internet have a significant impact on Brand Image for other consumers of products in Clothing and Online stores. However, there was no perceived impact based on these comments regarding Cosmetic products. No impact was found on other consumers' Purchase Intention. Management of Negative Comments (company's response to comments posted by the consumer on the internet) decreased the negative impact of comments on other consumer's Brand Image on product Online Store and the use of Regulatory Focus Theory on companies' responses did not cause significant differences, counter indicating this theoretical concept as a mean to improve the results of managing the comments posted by the consumer on the internet. Several implications of scientific and professional interest arise from this research. For a Marketing professional, it is evident that internet 2.0 should be considered in the media plan of a company and that it should be treated as a two-way communication channel with consumers.
"Exploiting channel symmetry in two-way channels." Thesis, 2010. http://hdl.handle.net/1911/61968.
Повний текст джерелаSteger, Christopher B. "Cooperative communication over two-way channels." Thesis, 2008. http://hdl.handle.net/1911/22269.
Повний текст джерела"Fundamental Limits of Two-pair Two-Way Relay Channels." 2016. http://repository.lib.cuhk.edu.hk/en/item/cuhk-1292194.
Повний текст джерелаThe first part of this thesis investigates the downlink transmission phase. For the downlink phase, each user is only interested in its partner’s message and treats the message for the other pair as interference. Suppose that the relay encodes messages for user pairs sequentially, i.e., message for one pair followed by message for the other pair. Then, the first message becomes noncausal interference for the remaining message, i.e., the encoder knows such interference prior to the encoding of the remaining message. Hence, the downlink transmission can be modeled as a broadcast channel with noncausal interference at the transmitter (i.e., the relay) and side information at the receivers (i.e., the users). We first obtain an achievable rate region of this system by extending Gelfand and Pinsker’s (GP’s) random binning method. We then apply the result to Gaussian scalar and vector channels, and consider the design of the auxiliary random variable used in the GP’s approach. Asymptotic analysis shows that our scheme is asymptotically capacityachieving at high signal-to-noise ratio (SNR) for both scalar and vector channels. We further investigate the system optimization in the finite SNR regime. Numerical results
show that our scheme can achieve a sum-rate close to the cut-set bound over a wide SNR range, and significantly outperforms the schemes that do not exploit the knowledge of noncausal interference at the transmitter.
The second part of this thesis studies the capacity of the Gaussian two-pair TWRC system, where each node is equipped with single antenna. For the Gaussian TWRC, the noises at the relay and the user nodes are Gaussian and independent of each other. Our main contribution is a message-reassembling strategy to decouple the coding design for the uplink and downlink transmissions. This strategy provides flexibility to fully exploit the channel randomness of both uplink and downlink. For the uplink transmission, each user transmits a superposition of Gaussian random codeword and nested lattice codeword, and the relay employs successive interference cancellation to decode signals. For the downlink transmission, the relay first reassembles and re-encodes messages, and then transmits a superposition of the resulting codewords. Finally, each user decodes the other user’s message of the same pair with the help of self-information. The analytical results show that the capacity region is achievable to within 1/2 bit per user.
The third part of this thesis extends our studies to the Gaussian two-pair multiinput multi-output (MIMO) TWRC system, where each node is equipped with multiple antennas. In the uplink phase, the relay’s received signal space is divided into two subspaces for each pair: in one subspace, the signals of the two users are near-parallel, and physical-layer network coding (PNC) decoding is applied to retrieve network-coded messages; in the other subspace, the two user signals are near-orthogonal, and complete decoding (CD) is applied to retrieve individual user messages. In the downlink phase, the relay’s transmit signal space is split into orthogonal subspaces for each pair, and in each subspace a common message is broadcasted to the two users. Our main contribution is to establish a critical link between the transmission scheme and the concept of principal angle in linear algebra. In particular, principal angle provides a way to quantify the degree of orthogonality between the user signals and helps determining how to partition the relay’s received signal space into PNC decoding subspace and CD decoding subspace. Building on that, we provide a near-optimal design of user/relay precoders for both uplink and downlink phases to maximize the asymptotic sum-rate of our scheme at high signal-tonoise ratio (SNR). The analysis and numerical results indicate that our scheme performs close to the cut-set bound and significantly outperforms existing schemes in the literature.
Xin, Haiyang.
Thesis Ph.D. Chinese University of Hong Kong 2016.
Includes bibliographical references (leaves ).
Abstracts also in Chinese.
Title from PDF title page (viewed on …).
"Transmission Strategies for Two-Way Relay Channels." Doctoral diss., 2015. http://hdl.handle.net/2286/R.I.36464.
Повний текст джерелаDissertation/Thesis
Doctoral Dissertation Electrical Engineering 2015
Rao, Yan-Ciao, and 饒硯喬. "A Study on Efficient Detection Techniques for Two-Way Relaying Channels." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/98308966448401301483.
Повний текст джерела國立暨南國際大學
電機工程學系
102
Two way relaying cooperative communications have recently been proved for improving the spectral efficiency successfully. Conventionally, minimum mean-squared error (MMSE) criterion and its successive interference cancellation (SIC) companion are used for detecting the signals at the relay. In this research, to achieve a better trade-off between the error rate performance and computational complexity, we propose to use a method learned from double space-time transmit diversity (DSTTD) systems for extracting the signals received. Simulations show that with our proposed scheme, a similar error rate can be achieved with less computation.
Su, Huan-Yu, and 蘇桓瑜. "Capacity Based Antenna Selection Scheme for Two Way AF MIMO Systems in Correlated Channels." Thesis, 2013. http://ndltd.ncl.edu.tw/handle/55252778706201360783.
Повний текст джерела國立中正大學
通訊工程研究所
101
Multiple-input multiple-output (MIMO) wireless communication systems combining with relay networks can obviously improve spatial diversity, transmission reliability and cover range without any further power consumption. However, MIMO communication system requires many radio frequency (RF) chains which are known to be quite expensive. Antenna selection schemes have been proposed in order to not only maintain system performance but also control the cost. In the thesis, a layered relay antenna selection algorithm is proposed based on the maximization of sum-rate in two-hop amplify-and-forward (AF) two-way MIMO multiple-relay systems under correlated channels. Finally, simulations results indicate that the proposed antenna selection algorithm compared with other existing antenna selection algorithms provides better sum-rate performance for half-duplex AF MIMO relay networks.
Lu, Keng-ju, and 呂庚儒. "Joint Transceiver/Relay Design for Two-Way AF-MIMO Relaying Transmission with Correlated Channels." Thesis, 2013. http://ndltd.ncl.edu.tw/handle/38818135552747275504.
Повний текст джерела國立中正大學
通訊工程研究所
101
In the thesis, the relay-precoder and the equalizer combined optimization is proposed in a two-way amplify-and-forward (AF) multiple-input multiple-output (MIMO) single-relay system with Gaussian random and correlated channel in both hops. With the aid of taking the correlated channel into account, a transceiver joint optimization design is developed based on the minimum mean-squared error (MMSE) criterion under power constraint at the relay. This optimization belongs to non-convex so that an iterative precoding design is applied to explore local optimal solutions. Simulation results demonstrate a better performance of the proposed iterative precoding design compared with other transceiver design with correlated channels.
Hsieh, Wei-Hsuan, and 謝維軒. "Blind estimation of channels for OFDM-based amplify-and-forward two-way relay network." Thesis, 2018. http://ndltd.ncl.edu.tw/handle/gct4mg.
Повний текст джерела國立臺灣大學
電信工程學研究所
106
Orthogonal frequency division multiplexing (OFDM) systems has recently received considerable interest for its advantages in high-bit-rate transmissions over frequency selective fading channels. In the last decade, wireless relay network becomes an active research due to its reliability, effective spectral and power efficiency. In particular, two-way relay network (TWRN) has drawn a lot of attention because its overall communication rate is approximately twice of that achieved in the conventional one-way relay network (OWRN). This thesis studies the blind channels estimation for amplify-and-forward (AF) TWRN in cyclic-prefixed OFDM (CP-OFDM) and in zero-padded OFDM (ZP-OFDM) systems. For CP-OFDM systems, we propose three methods to estimate the first cascaded channel resulting in self-interference. These methods are circular repetition method, incorporation of cyclic-prefixed into estimation method and subspace method. Then, we investigate the estimation accuracy of the first cascaded channel when there exist virtual carriers (VC) for different methods. Also we propose a least-squares carrier frequency offset (CFO) estimation method by using VC. After that, the second cascaded channel which is from the source to destination is estimated by nulling method. The algorithm for the second cascaded channel can use repetition method to handle the case of few received blocks. In addition, we also extend our channel estimation methods to the case of ZP-OFDM systems. Simulation results are carried out to verify the performance of the proposed methods.
Lee, Yu-Ru, and 李玉如. "Joint Power Allocation and Relay Selection Schemes for Two-Way AF Relay Systems with Nonreciprocal Channels." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/96617162812033092747.
Повний текст джерела國立清華大學
通訊工程研究所
102
In this thesis, we present two suboptimal joint power allocation (PA) and relay selection (RS) schemes with different design objectives for two-way amplify-and-forward relay systems with nonreciprocal channels, where multiple single-antenna relays are considered and only one relay is selected for cooperation with two sources. The first approach is to maximize the smaller received signal-to-noise ratios (SNRs) at the two sources under a total transmit power constraint, where closed-form PA expressions are derived to make the received SNRs at the two sources equal for each relay, and the relay resulting in the largest balanced received SNR at the two sources is selected for cooperation. The second approach is to minimize the total transmit power under received SNR constraints at the two sources, where closed-from PA expressions are obtained based on a standard convex optimization procedure for each relay, and the relay resulting in the minimum total transmit power is selected for cooperation. It is shown that earlier works relating to these two approaches for reciprocal channels are special cases of the proposed joint PA-RS schemes. Moreover, computer simulation results show that both the proposed PA schemes without RS provide better performance than the equal PA scheme, and that using the proposed RS schemes with their own corresponding proposed PA schemes further enhances the system performance.
Tang, Kang-Tsao, and 湯剛造. "Capacity-Based Relay-and-Antenna Joint Selection Schemes for Two-Way AF-MIMO Multiple-Relay Systems in Correlated Channels." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/29e6pd.
Повний текст джерела國立中正大學
通訊工程研究所
102
The relay and antenna joint selection algorithms are proposed for the two-way amplify-and-forward (AF) multiple-input multiple-output (MIMO) multiple-relay systems in the thesis. Based on the maximization of system sum-rate capacity, both the layered distributed orthogonal relay selection (LDORS) and the singular value decomposition (SVD) based selection strategies are investigated. The LDORS scheme operates in a layered selection manner to sieve out the antenna pairs on relays by making full use of the Gram-Schmidt (GS) orthogonalization procedure and the DORS algorithm. In addition, the 2-stage SVD-based antenna selection algorithm is proposed to alleviate the complexity cost incurred by the SVD-based exhaustive search method. Finally, simulation results demonstrate that the proposed relay-and-antenna selection techniques are capable of providing the superior sum-rate performance for the two-way AF-MIMO multiple-relay systems.
Wu, Hong-Syuan, and 吳鴻軒. "Performance Analysis of Relay Selection Using Enhanced Static Decode and Forward With Network Coding in Two-Way Relay Channels." Thesis, 2013. http://ndltd.ncl.edu.tw/handle/46336680336315147994.
Повний текст джерела國立中正大學
通訊工程研究所
101
Along with the development of mobile communications, we have more usage in wireless transmission. Consequently, we need high quality in transmission, and the influence of fading channel will be an important factor. In this thesis, we adopt the relay selection which use Enhanced Static Decode and Forward with Network Coding (RS-ESDF-NC) in tow-way relay channels. We assume all nodes are in the half-duplex mode. Our scheme first select the optimal relay from a set of L relays. By using Min-Max relay selection criterion, we can find the optimal relay, and then uses this optimal relay. So that users exchange their information with the help of best relay.We consider three different fading channels (Rayleigh、Rician、Nakagami). The outage probability is improved when the number of relay stations increases, and The outage probability of RS-ESDF-NC is better than that ESDF-NC. The simulation results show that our system has lower outage probability which means the improvement of the reliability of the system.
Liu, Yu-Chen, and 劉祐蓁. "Performance Analysis of Relay Selection With Enhanced Dynamic Decode-and-Forward and Network Coding in Two-Way Relay Channels." Thesis, 2013. http://ndltd.ncl.edu.tw/handle/25357093764916564589.
Повний текст джерела國立中正大學
通訊工程研究所
101
In this thesis, we adopt the relay selection (RS) protocol proposed by Bletsas,Khisti, Reed and Lippman (2006) with Enhanced Dynamic Decode-and-Forward(EDDF) and network coding (NC) system in a two-hop two-way multi-relay network.All nodes are single-input single-output (SISO) and half-duplex, i.e., they cannot transmit and receive data simultaneously. The outage probability is analyzed and we show comparisons of outage probability with various scenarios under Rayleigh, Rician and Nakagami fading channels. Our results show that the relay selection with EDDF and network coding (RS-EDDF&NC) scheme has the best performance in the sense of outage probability upon the considered decode-and-forward (DF) relaying if there exist sufficiently relays. In addition, the performance loss is large if we select a relay at random. This shows the importance of relay selection strategies.
Tsai, Kai-Chu, and 蔡凱竹. "Blind Estimation of Channels, CFO, I/Q Imbalance and STO for OFDM-Based Amplify-and-Forward Two-Way Relay Network." Thesis, 2017. http://ndltd.ncl.edu.tw/handle/fxnq38.
Повний текст джерела國立臺灣大學
電信工程學研究所
105
Orthogonal frequency division multiplexing (OFDM) has recently received considerable interest for its advantages in high-bit-rate transmissions over frequency-selective fading channels. Lately, wireless relay network becomes an active research due to its reliability, effective spectral and power efficiency. In particular, two-way relay network (TWRN) has become popular because its throughput is twice that of the conventional one-way relay network (OWRN). This thesis studies the blind channels, carrier frequency offset (CFO), in-phase and quadrature-phase (I/Q) imbalance and symbol timing offset (STO) estimation for amplify-and-forward (AF) TWRN CP-OFDM systems. Firstly, we use power reduction method to estimate the first cascaded channel resulting in self-interference. Secondly, we will show how to apply cyclic-prefix based algorithm to estimate CFO and I/Q imbalance jointly. After compensation of CFO and I/Q imbalance, we utilized subspace based method to estimate the second cascaded channel from source to destination. Moreover, the proposed method can be applied to multiple relay nodes. In addition, the effect of STO in self-interference signals is investigated. A blind algorithm is proposed for the estimation of STO. Simulations are carried out to verify the performance of the proposed method.
Hsu, Ching-Hao, and 徐慶豪. "Network Coding and Distributed Space-Time Block Codes with Adaptive AAF/DAF Elements for Two-Way Relay in Impulsive Noise Channels." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/sq9te6.
Повний текст джерела國立臺北科技大學
電腦與通訊研究所
102
In the two-way relay networks with two relays between two nodes, the previous scheme proposed a two-way relay network coding system using all Decode-and-Forward (DAF) elements without STBC. In our proposed scheme, we transmit using Alamouti DSTBC with adaptive AAF/DAF elements. The simulation result shows that at 10-2 BER our proposed scheme is better than the previous scheme by 1.2dB,1.8dB,2dB and 2.2dB forδ = 2,1.44,1 and 0.8, respectively.
Wang, Ping-Chung, and 王品中. "Channel Estimation for Two Way Relay Networks." Thesis, 2011. http://ndltd.ncl.edu.tw/handle/38187850388539477354.
Повний текст джерелаBanijamali, Seyedershad. "Gaussian Two-Way Channel with Constellation-based Input." Thesis, 2013. http://hdl.handle.net/10012/7272.
Повний текст джерелаNwaekwe, Chinwe M. "Channel estimation in a two-way relay network." Thesis, 2011. http://hdl.handle.net/10155/174.
Повний текст джерелаUOIT
Zhang, Haoyuan. "Cross-layer design for multi-hop two-way relay network." Thesis, 2017. http://hdl.handle.net/1828/8307.
Повний текст джерелаGraduate
Dash, Debashis. "Bounds and protocols for a two-way multiple node channel." Thesis, 2007. http://hdl.handle.net/1911/20499.
Повний текст джерелаHern, Brett Michael. "Coding Schemes for Physical Layer Network Coding Over a Two-Way Relay Channel." Thesis, 2013. http://hdl.handle.net/1969.1/151149.
Повний текст джерелаChang, Yuan-ann, and 張元安. "Using Two-Way Partition Method for Multi-Channel Broadcasting in Mobile Environment." Thesis, 2005. http://ndltd.ncl.edu.tw/handle/71635284198968750807.
Повний текст джерела南華大學
資訊管理學研究所
93
Owing to the advance of wireless communication techniques, a mobile user can access the desired data anytime anywhere. Due to the limit of mobile device, data broadcasting is an efficient method for save bandwidth. In the multi-channel, the data can be equally distributed to different channels for reduce the broadcast cycle and reduce the client which access data item. When a mobile user submits an issue for a data set that it distributed to different broadcast channels, the state called data competition. When the numbers of data competition increase, the data collision increase also, therefore, the mobile user must wait for next broadcast cycle, and thus the mobile user needs more time to access data set. The state called data collision. In this article, we propose the Two-Way Partition Algorithm and apply it to data partition of multi-channel. We use the result of data partition to reduce the data competition. Finally, we evaluate the performance of the algorithm and compare the data competition times that influence with initial states’ and using our algorithm. The result shows that our approach significantly reduces the data competition times.
Huang, Chao-Wei, and 黃昭瑋. "Two-Way Training Design for Discriminatory Channel Estimation in Wireless MIMO Systems." Thesis, 2011. http://ndltd.ncl.edu.tw/handle/39052366661285591678.
Повний текст джерела國立清華大學
通訊工程研究所
99
Thisworkexaminestheuseoftwo-waytraininginmultiple-inputmultiple-output(MIMO)wirelesssystemstodiscriminatethechannelestimationperformancesbetweenalegitimatereceiver(LR)andanunauthorizedreceiver(UR).Thisthesisextendsuponthepreviouslyproposeddiscriminatorychannelestimation(DCE)schemethatallowsonlythetransmittertosendtrainingsignals.ThegoalofDCEistominimizethechannelestimationerroratLRwhilerequiringthechannelestimationerroratURtoremainbeyondacertainlevel.Ifthetrainingsignalissentonlybythetransmitter,theperformancediscriminationbetweenLRandURwillbelimitedsincethetrainingsignalshelpbothreceiversperformestimatesoftheirdownlinkchannels.Inthiswork,weconsiderinsteadthetwo-waytrainingmethod-ologythatallowsboththetransmitterandLRtosendtrainingsignals.Inthiscase,thetrainingsignalsentbyLRhelpsthetransmitterobtainknowledgeofthetransmitter-to-LRchannel,butdoesnothelpURestimateitsdownlinkchannel(i.e.,thetransmitter-to-URchannel).Withtransmitterknowledgeoftheestimatedtransmitter-to-LRchannel,artificialnoise(AN)canthenbeembeddedinthenullspaceofthetransmitter-to-LRchanneltodisruptUR’schannelestimationwithoutseverelydegradingthechannelestimationatLR.Basedontheseideas,two-wayDCEtrainingschemesaredevelopedforbothreciprocalandnon-reciprocalchannels.TheoptimalpowerallocationbetweentrainingandANsignalsisdevisedunderbothaverageandindividualpowerconstraints.Numericalresultsareprovidedtodemonstratetheefficacyoftheproposedtwo-wayDCEtrainingschemes.
Shao, Yi-Chi, and 邵貽琦. "On Malicious Behavior in Two-Way Relay Channel withVariable Analog Network Coding." Thesis, 2013. http://ndltd.ncl.edu.tw/handle/65170988734880456941.
Повний текст джерела國立臺灣大學
電信工程學研究所
101
The two-way relay channel is a fundamental building block of the cooperative wireless networks, where two sources want to exchange messages via relays. Most works in the literature on the relay networks assume that all terminals are fully cooperative. In this thesis, we consider a two-way relay channel that contains a malicious relay, and a cooperative relay which adopts the celebrated analog network coding (ANC). We aim to understand the optimal strategies of these two relays via mutual information games. The cooperative and malicious relays are two players in our game and the achievable sum rates are adopted as the utilities. The optimal transmission strategies of both types of relays are derived by identifying the Nash equilibrium (NE) of the proposed game. By allowing relays to change transmission actions symbol by symbol in a codeword length, the proposed game generalizes the mutual information games in previous works. With this new game formulation, the pure strategy NE exists where the cooperative relay is suggested to vary the amplifying coefficients of the ANC symbol by symbol even for a fixed channel. However, owing to the non-convex nature of our utilities, it is still hard to explicitly derive the pure strategy NE. To overcome this problem, the utilities are linearized. Furthermore, the special cases of our results also show that the malicious attacks proposed by previous works for the one-way relay channel may not be optimal.
Yazdan, Panah Ali. "Relay-aided communications with partial channel state information." Thesis, 2011. http://hdl.handle.net/2152/ETD-UT-2011-08-4264.
Повний текст джерелаtext
Al, Humaidi Fadhel. "Optimal power minimization in two-way relay network with imperfect channel state information." Thesis, 2010. http://hdl.handle.net/10155/113.
Повний текст джерелаUOIT
Lu, Po-Hsun, and 陸柏勳. "Blind Channel Estimation in OFDM Coded Two-Way Amplify-And-Forward Relay Systems." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/34553081117451841752.
Повний текст джерела國立臺灣大學
電信工程學研究所
102
Orthogonal frequency division multiplexing (OFDM) has recently received considerable interest for its advantages in high-bit-rate transmissions over frequency-selective fading channels. Recently, research on wireless relay networks becomes popular because of the following reasons. When a transmitter and a receiver are unable to communicate with each other because of the distance between them or fading of the channel, they can be connected by one or multiple relay nodes to create an alternate route. Relay transmission can enhance the reliability, increase the rate in wireless networks. Relay transmission provides an effective means of improving spectral and power efficiency. In addition, the use of multiple antennas to achieve transmit diversity in the cellular uplink is impractical due to the size constraints at each mobile. Cooperative communication can overcome this constraint problem. Relay nodes cooperate with terminals of the users when each relay nodes transmit its own information to destination by processing the information from source. This thesis studies the blind channel estimation for amplify-and-forward(AF) TWRN ZP-OFDM systems. We will show how to apply the subspace-based blind channel estimation algorithm for the case of TWRN ZP-OFDM systems. Pilots for estimating the scalar ambiguity in blind channel estimation are also derived. Simulations are carried out to verify the performance of the proposed method. Compared with the existing blind channel estimation method in TWRN, our proposed method has a better performance.
"Channel Estimation in Half and Full Duplex Relays." Doctoral diss., 2018. http://hdl.handle.net/2286/R.I.50487.
Повний текст джерелаDissertation/Thesis
Doctoral Dissertation Electrical Engineering 2018
Schnurr, Clemens [Verfasser]. "Achievable rates and coding strategies for the two-way relay channel / von Clemens Schnurr." 2008. http://d-nb.info/990689727/34.
Повний текст джерелаLi, Sheng-Hung, and 李聖弘. "Performance Analysis of Relay Selection in Two-Way Relay Networks with Channel Estimation Error." Thesis, 2015. http://ndltd.ncl.edu.tw/handle/8msjk8.
Повний текст джерела國立中山大學
通訊工程研究所
103
The impact of channel estimation errors is investigated in two-way relay networks (TWRNs) with two different channel state information (CSI) estimation schemes, namely, cascaded and separate. In the cascaded scheme, the relay node is selected on the basis of the CSI of the individual channels between the source nodes and the relay node. In the separate scheme, relay node selection is based on the CSI of the cascaded channel between the two source nodes. For both estimation schemes, the effect of the CSI estimation error on the outage probability is examined by Cramer-Rao lower bound. Contrary to previous reports, the source nodes in the TWRN are assumed to yield different estimation errors. Numerical results confirm the validity of the derived expression and indicate that the presence of different estimation errors at the two source nodes can significantly influence the performance of the TWRN. However, we extend the relay selection problem to non-reciprocal TWRNs. We propose a selection scheme based on the concept of censoring rule, in which each relay node can decide whether the received signal should be forwarded. This method can save a level of transmission power and maintain the diversity gain without gathering all of the CSI between the source nodes and relay nodes at a central node. The effectiveness of the proposed scheme is evident in the simulation results.
Chiu, Po-Chun, and 邱泊鈞. "Joint Time Synchronization and Channel Estimation for Two-Way Amplify-and-Forward Relay Systems." Thesis, 2013. http://ndltd.ncl.edu.tw/handle/77686428256542237738.
Повний текст джерела國立清華大學
通訊工程研究所
101
In this thesis, we consider a two-way relay system where two terminals exchange their information via an amplify-and-forward relay in a bi-directional manner. Due to the two-way relay protocol, signals from both terminals travel through different cascaded channels and this makes synchronization and channel estimation much more complicated than those in conventional one-way relay systems. To cope with these problems, we propose a joint time synchronization and channel estimation scheme based on a specific training sequence arrangement, where each terminal’s training sequence consists of a perfect sequence (with an ideal auto-correlation function) attached by an appropriate cyclic prefix and postfix. The proposed scheme relies on a first channel tap selection process, whose performance is highly dependent on the choice of a threshold to distinguish the signal outputs from noise. By analyzing some possible probability density functions of the correlator output, we derive optimal thresholds for selection of the first channel tap. With these thresholds, the proposed scheme provides better time synchronization performance than the maximum-likelihood approach for low signal-to-noise ratio (SNR) cases; both have similar performance for high SNR cases. It is also shown that the proposed scheme involves much less computational complexity than the maximum-likelihood approach.
Chen, Chun-Ting, and 陳俊廷. "Analysis of the Degrees of Freedom of Two-Way MIMO Broadcast Channel with Delayed CSIT." Thesis, 2015. http://ndltd.ncl.edu.tw/handle/ddwyu7.
Повний текст джерела元智大學
通訊工程學系
104
Nowadays, perfect channel state information at transmitters (CSIT) is widely assumed in the study of multiple-input multiple-output (MIMO) systems. All of the transmitters and receivers know the channel state information to support the use of the zero-forcing scheme [1] and interference alignment scheme [2]. Cadambe and Jafar proposed the interference alignment scheme [2] for K-user interference channel with perfect CSIT. However, we hope we can use the completely stale transmitter channel to assist receivers on decoding the message. David Tse and Maddah-Ali proposed a method to decode the receiver messages that uses the delayed CSIT. In this thesis, we modify the channel model that David Tse and Maddah-Ali studied. Finally, we discuss the degrees of freedom and compare channel rate for simulation.
Chen, Yu-Ching, and 陳予勁. "Artificial Noise Design for Two-Way Training Based Discriminatory Channel Estimation in Wireless MIMO Systems." Thesis, 2013. http://ndltd.ncl.edu.tw/handle/80553890200023117660.
Повний текст джерелаWang, Chenyuan. "Performance evaluation and enhancement for AF two-way relaying in the presence of channel estimation error." Thesis, 2012. http://hdl.handle.net/1828/3954.
Повний текст джерелаGraduate