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Yeap, Bee Leong. "Turbo equalisation algorithms for full and partial response modulation". Thesis, University of Southampton, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.310853.
Pełny tekst źródłaShaheem, Asri. "Iterative detection for wireless communications". University of Western Australia. School of Electrical, Electronic and Computer Engineering, 2008. http://theses.library.uwa.edu.au/adt-WU2008.0223.
Pełny tekst źródłaWang, Jin. "Iterative source decoding, channel decoding and channel equalisation". Thesis, University of Southampton, 2007. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.435723.
Pełny tekst źródłaIrizar, JoseÌ MariÌa Zabalegui. "Combined equalisation and decoding for OFDM over wireless fading channels". Thesis, Staffordshire University, 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.272580.
Pełny tekst źródłaAbdulrazaq, Muhammad Bashir. "Reducing the complexity of equalisation and decoding of shingled writing". Thesis, University of Plymouth, 2017. http://hdl.handle.net/10026.1/9332.
Pełny tekst źródłaIwaza, Lana, i Lana Iwaza. "Joint Source-Network Coding & Decoding". Phd thesis, Université Paris Sud - Paris XI, 2013. http://tel.archives-ouvertes.fr/tel-00855787.
Pełny tekst źródłaIwaza, Lana. "Joint Source-Network Coding & Decoding". Thesis, Paris 11, 2013. http://www.theses.fr/2013PA112048/document.
Pełny tekst źródłaWhile network data transmission was traditionally accomplished via routing, network coding (NC) broke this rule by allowing network nodes to perform linear combinations of the upcoming data packets. Network operations are performed in a specific Galois field of fixed size q. Decoding only involves a Gaussian elimination with the received network-coded packets. However, in practical wireless environments, NC might be susceptible to transmission errors caused by noise, fading, or interference. This drawback is quite problematic for real-time applications, such as multimediacontent delivery, where timing constraints may lead to the reception of an insufficient number of packets and consequently to difficulties in decoding the transmitted sources. At best, some packets can be recovered, while in the worst case, the receiver is unable to recover any of the transmitted packets.In this thesis, we propose joint source-network coding and decoding schemes in the purpose of providing an approximate reconstruction of the source in situations where perfect decoding is not possible. The main motivation comes from the fact that source redundancy can be exploited at the decoder in order to estimate the transmitted packets, even when some of them are missing. The redundancy can be either natural, i.e, already existing, or artificial, i.e, externally introduced.Regarding artificial redundancy, we choose multiple description coding (MDC) as a way of introducing structured correlation among uncorrelated packets. By combining MDC and NC, we aim to ensure a reconstruction quality that improves gradually with the number of received network-coded packets. We consider two different approaches for generating descriptions. The first technique consists in generating multiple descriptions via a real-valued frame expansion applied at the source before quantization. Data recovery is then achieved via the solution of a mixed integerlinear problem. The second technique uses a correlating transform in some Galois field in order to generate descriptions, and decoding involves a simple Gaussian elimination. Such schemes are particularly interesting for multimedia contents delivery, such as video streaming, where quality increases with the number of received descriptions.Another application of such schemes would be multicasting or broadcasting data towards mobile terminals experiencing different channel conditions. The channel is modeled as a binary symmetric channel (BSC) and we study the effect on the decoding quality for both proposed schemes. Performance comparison with a traditional NC scheme is also provided.Concerning natural redundancy, a typical scenario would be a wireless sensor network, where geographically distributed sources capture spatially correlated measures. We propose a scheme that aims at exploiting this spatial redundancy, and provide an estimation of the transmitted measurement samples via the solution of an integer quadratic problem. The obtained reconstruction quality is compared with the one provided by a classical NC scheme
Palanivelu, Arul Durai Murugan. "Tree search algorithms for joint detection and decoding". Columbus, Ohio : Ohio State University, 2006. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=osu1145039374.
Pełny tekst źródłaVu, Xuan Thang. "Joint Network / Channel Decoding over Noisy Wireless Networks". Phd thesis, Université Paris Sud - Paris XI, 2014. http://tel.archives-ouvertes.fr/tel-01060330.
Pełny tekst źródłaLi, Si 1981. "Joint synchronization, channel estimation and decoding techniques in OFDM systems". Thesis, McGill University, 2006. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=99522.
Pełny tekst źródłaIn this thesis, we study and develop joint synchronization, channel estimation and decoding schemes to provide high system performance at a relatively low complexity for uncoded and coded OFDM systems.
We first investigate and evaluate the performance of low-complexity time-domain joint synchronization and channel estimation scheme suitable for uncoded OFDM systems. The proposed scheme can operate with a large initial CFO range (up to +/-100% of carrier spacing). Its complexity is reduced by using a special FFT block for time-to-frequency channel response conversion and a track-and-hold (TAH) estimation strategy based on mid-ambles to eliminate the additional IFFT block required by time-domain estimation.
We then consider the turbo concept to develop an iterative joint synchronization, channel estimation and decoding scheme for coded OFDM systems operating at very low signal-to-noise ratios (SNRs). Instead of hard decisions, the estimator uses soft decisions of the transmitted data obtained from previous soft-input soft-output (SISO) decoder and consequently produces better estimates of the unknown parameters. These estimation results will then help data detector to generate more reliable soft inputs to the decoder. The whole process will be performed in an iterative manner and good system performance can be achieved with only a few iterations for moderate initial synchronization errors.
Vital, Juan Carlos Serrato. "Single and joint iterative decoding for higher order modulation schemes". Thesis, University of Leeds, 2008. http://etheses.whiterose.ac.uk/730/.
Pełny tekst źródłaPu, Lingling, Zhenyu Wu, Ali Bilgin, Michael W. Marcellin i Bane Vasic. "LDPC-BASED ITERATIVE JOINT SOURCE/CHANNEL DECODING SCHEME FOR JPEG2000". International Foundation for Telemetering, 2004. http://hdl.handle.net/10150/605781.
Pełny tekst źródłaThis paper presents a joint source-channel decoding scheme based on a JPEG2000 source coder and an LDPC channel coder. At the encoder, JPEG2000 is used to perform source coding with certain error resilience (ER) modes, and LDPC codes are used to perform channel coding. At the decoder, after one iteration of LDPC decoding, the output codestream is then decoded by JPEG2000. With the error resilience mode switches on, the source decoder detects the position of the first error within each codeblock of the JPEG2000 codestream. This information is fed back to the channel decoder, and incorporated into the calculation of likelihood values of variable nodes for the next iteration of LDPC decoding. Our results indicate that the proposed method has significant gains over conventional separate channel and source decoding.
Luo, Yuhui. "A mixed cross-correlation and constant modulus adaptive algorithm for joint blind equalisation and source separation". Thesis, Imperial College London, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.270380.
Pełny tekst źródłaTsai, Meng-Ying (Brady). "Iterative joint detection and decoding of LDPC-Coded V-BLAST systems". Thesis, Kingston, Ont. : [s.n.], 2008. http://hdl.handle.net/1974/1304.
Pełny tekst źródłaZhu, Chuan. "Joint source-channel decoding and unequal error protection aided video transmission". Thesis, University of Southampton, 2016. https://eprints.soton.ac.uk/400650/.
Pełny tekst źródłaMinallah, Nasru. "Low-bit-rate joint source-channel decoding aided wireless video communications". Thesis, University of Southampton, 2010. https://eprints.soton.ac.uk/159195/.
Pełny tekst źródłaSinghal, Rohit. "Multiple symbol decoding of differential space-time codes". Texas A&M University, 2003. http://hdl.handle.net/1969.1/344.
Pełny tekst źródłaRadhakrishnan, Rathnakumar. "Detection and Decoding for Magnetic Storage Systems". Diss., The University of Arizona, 2009. http://hdl.handle.net/10150/194396.
Pełny tekst źródłaKOBAYASHI, Kentaro, Takaya YAMAZATO, Hiraku OKADA i Masaaki KATAYAMA. "Joint Channel Decoding of Spatially and Temporally Correlated Data in Wireless Sensor Networks". IEEE, 2008. http://hdl.handle.net/2237/12086.
Pełny tekst źródłaNangare, Nitin Ashok. "Non-iterative joint decoding and signal processing: universal coding approach for channels with memory". Texas A&M University, 2003. http://hdl.handle.net/1969.1/3899.
Pełny tekst źródłaDubuc, Christian. "Joint iterative demodulation and decoding for turbo-coded PSK signals on flat fading channels". Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2000. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape4/PQDD_0017/MQ57725.pdf.
Pełny tekst źródłaSubbalakshmi, K. P. "Joint source-channel decoding of variable-length encoded sources with applications to image transmission". Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2000. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape4/PQDD_0013/NQ61684.pdf.
Pełny tekst źródłaDubuc, Christian Carleton University Dissertation Engineering Systems and Computer. "Joint iterative demodulation and decoding for turbo-coded PSK signals on flat fading channels". Ottawa, 2000.
Znajdź pełny tekst źródłaIllangakoon, Chathura. "On joint source-channel decoding and interference cancellation in CDMA-based large-scale wireless sensor networks". IEEE, 2013. http://hdl.handle.net/1993/22019.
Pełny tekst źródłaKobayashi, Kentaro, Takaya Yamazato, Hiraku Okada i Masaaki Katayama. "Iterative Joint Channel-Decoding Scheme Using the Correlation of Transmitted Information Sequences in Sensor Networks". IEEE, 2006. http://hdl.handle.net/2237/7755.
Pełny tekst źródłaShiao, Fu-Sheng. "Combined Channel Estimation and Turbo Equalization for Wireless Channels". Thesis, University of Canterbury. Electrical and Computer Engineering, 2007. http://hdl.handle.net/10092/1189.
Pełny tekst źródłaEspaña, Boquera Salvador. "Contributions to the joint segmentation and classification of sequences (My two cents on decoding and handwriting recognition)". Doctoral thesis, Universitat Politècnica de València, 2016. http://hdl.handle.net/10251/62215.
Pełny tekst źródła[ES] Este trabajo se centra en problemas (como reconocimiento automático del habla (ASR) o de escritura manuscrita (HTR)) que cumplen: 1) pueden representarse (quizás aproximadamente) en términos de secuencias unidimensionales, 2) su resolución implica descomponer la secuencia en segmentos que se pueden clasificar en un conjunto finito de unidades. Las tareas de segmentación y de clasificación necesarias están tan intrínsecamente interrelacionadas ("paradoja de Sayre") que deben realizarse conjuntamente. Nos hemos inspirado en lo que algunos autores denominan "La trilogía exitosa", refereido a la sinergia obtenida cuando se tiene: - un buen formalismo, que dé lugar a buenos algoritmos; - un diseño e implementación ingeniosos y eficientes, que saquen provecho de las características del hardware; - no descuidar el "saber hacer" de la tarea, un buen preproceso y el ajuste adecuado de los diversos parámetros. Describimos y estudiamos "modelos generativos en dos etapas" sin reordenamientos (TSGMs), que incluyen no sólo los modelos ocultos de Markov (HMM), sino también modelos segmentales (SMs). Se puede obtener un decodificador de "dos pasos" considerando a la inversa un TSGM introduciendo no determinismo: 1) se genera un grafo acíclico dirigido (DAG) y 2) se utiliza conjuntamente con un modelo de lenguaje (LM). El decodificador de "un paso" es un caso particular. Se formaliza el proceso de decodificación con ecuaciones de lenguajes y semianillos, se propone el uso de redes de transición recurrente (RTNs) como forma normal de gramáticas de contexto libre (CFGs) y se utiliza el paradigma de análisis por composición de manera que el análisis de CFGs resulta una extensión del análisis de FSA. Se proponen algoritmos de composición de transductores que permite el uso de RTNs y que no necesita recurrir a composición de filtros incluso en presencia de transiciones nulas y semianillos no idempotentes. Se propone una extensa revisión de LMs y algunas contribuciones relacionadas con su interfaz, con su representación y con la evaluación de LMs basados en redes neuronales (NNLMs). Se ha realizado una revisión de SMs que incluye SMs basados en combinación de modelos generativos y discriminativos, así como un esquema general de tipos de emisión de tramas y de SMs. Se proponen versiones especializadas del algoritmo de Viterbi para modelos de léxico y que manipulan estados activos sin recurrir a estructuras de tipo diccionario, sacando provecho de la caché. Se ha propuesto una arquitectura "dataflow" para obtener reconocedores a partir de un pequeño conjunto de piezas básicas con un protocolo de serialización de DAGs. Describimos generadores de DAGs que pueden tener en cuenta restricciones sobre la segmentación, utilizar modelos segmentales no limitados a HMMs, hacer uso de los decodificadores especializados propuestos en este trabajo y utilizar un transductor de control que permite el uso de unidades dependientes del contexto. Los decodificadores de DAGs hacen uso de un interfaz bastante general de LMs que ha sido extendido para permitir el uso de RTNs. Se proponen también mejoras para reconocedores "un paso" basados en algoritmos especializados para léxicos y en la interfaz de LMs en modo "bunch", así como su paralelización. La parte experimental está centrada en HTR en diversas modalidades de adquisición (offline, bimodal). Hemos propuesto técnicas novedosas para el preproceso de escritura que evita el uso de heurísticos geométricos. En su lugar, utiliza redes neuronales. Se ha probado con HMMs hibridados con redes neuronales consiguiendo, para la base de datos IAM, algunos de los mejores resultados publicados. También podemos mencionar el uso de información de sobre-segmentación, aproximaciones sin restricción de un léxico, experimentos con datos bimodales o la combinación de HMMs híbridos con reconocedores de tipo holístico.
[CAT] Aquest treball es centra en problemes (com el reconeiximent automàtic de la parla (ASR) o de l'escriptura manuscrita (HTR)) on: 1) les dades es poden representar (almenys aproximadament) mitjançant seqüències unidimensionals, 2) cal descompondre la seqüència en segments que poden pertanyer a un nombre finit de tipus. Sovint, ambdues tasques es relacionen de manera tan estreta que resulta impossible separar-les ("paradoxa de Sayre") i s'han de realitzar de manera conjunta. Ens hem inspirat pel que alguns autors anomenen "trilogia exitosa", referit a la sinèrgia obtinguda quan prenim en compte: - un bon formalisme, que done lloc a bons algorismes; - un diseny i una implementació eficients, amb ingeni, que facen bon us de les particularitats del maquinari; - no perdre de vista el "saber fer", emprar un preprocés adequat i fer bon us dels diversos paràmetres. Descrivim i estudiem "models generatiu amb dues etapes" sense reordenaments (TSGMs), que inclouen no sols inclouen els models ocults de Markov (HMM), sinò també models segmentals (SM). Es pot obtindre un decodificador "en dues etapes" considerant a l'inrevés un TSGM introduint no determinisme: 1) es genera un graf acíclic dirigit (DAG) que 2) és emprat conjuntament amb un model de llenguatge (LM). El decodificador "d'un pas" en és un cas particular. Descrivim i formalitzem del procés de decodificació basada en equacions de llenguatges i en semianells. Proposem emprar xarxes de transició recurrent (RTNs) com forma normal de gramàtiques incontextuals (CFGs) i s'empra el paradigma d'anàlisi sintàctic mitjançant composició de manera que l'anàlisi de CFGs resulta una lleugera extensió de l'anàlisi de FSA. Es proposen algorismes de composició de transductors que poden emprar RTNs i que no necessiten recorrer a la composició amb filtres fins i tot amb transicions nul.les i semianells no idempotents. Es proposa una extensa revisió de LMs i algunes contribucions relacionades amb la seva interfície, amb la seva representació i amb l'avaluació de LMs basats en xarxes neuronals (NNLMs). S'ha realitzat una revisió de SMs que inclou SMs basats en la combinació de models generatius i discriminatius, així com un esquema general de tipus d'emissió de trames i altre de SMs. Es proposen versions especialitzades de l'algorisme de Viterbi per a models de lèxic que permeten emprar estats actius sense haver de recórrer a estructures de dades de tipus diccionari, i que trauen profit de la caché. S'ha proposat una arquitectura de flux de dades o "dataflow" per obtindre diversos reconeixedors a partir d'un xicotet conjunt de peces amb un protocol de serialització de DAGs. Descrivim generadors de DAGs capaços de tindre en compte restriccions sobre la segmentació, emprar models segmentals no limitats a HMMs, fer us dels decodificadors especialitzats proposats en aquest treball i emprar un transductor de control que permet emprar unitats dependents del contexte. Els decodificadors de DAGs fan us d'una interfície de LMs prou general que ha segut extesa per permetre l'ús de RTNs. Es proposen millores per a reconeixedors de tipus "un pas" basats en els algorismes especialitzats per a lèxics i en la interfície de LMs en mode "bunch", així com la seua paral.lelització. La part experimental està centrada en el reconeiximent d'escriptura en diverses modalitats d'adquisició (offline, bimodal). Proposem un preprocés d'escriptura manuscrita evitant l'us d'heurístics geomètrics, en el seu lloc emprem xarxes neuronals. S'han emprat HMMs hibridats amb xarxes neuronals aconseguint, per a la base de dades IAM, alguns dels millors resultats publicats. També podem mencionar l'ús d'informació de sobre-segmentació, aproximacions sense restricció a un lèxic, experiments amb dades bimodals o la combinació de HMMs híbrids amb classificadors holístics.
España Boquera, S. (2016). Contributions to the joint segmentation and classification of sequences (My two cents on decoding and handwriting recognition) [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/62215
TESIS
Premiado
Lu, P. S. (Pen-Shun). "Decoding and lossy forwarding based multiple access relaying". Doctoral thesis, Oulun yliopisto, 2015. http://urn.fi/urn:isbn:9789526207742.
Pełny tekst źródłaTiivistelmä Tämän väitöskirjan tarkoituksena on tuottaa yhtenäinen kokonaisuus häviöllisestä lähetyksestä pura-ja-lähetä (DF) -pohjaisessa monikäyttörelejärjestelmässä (MARC) sekä teoreettisesta että käytännöllisestä näkökulmasta. Parantaakseen resurssi- tai aikarajoitetun MARC-järjestelmän suorituskykyä, vastaanotin hyödyntää riippuvuussuhdetta releen välittämien informaatiosekvenssien virheellisten estimaattien ja suoraan lähteestä tulevien informaatiosekvenssien välillä (e-MARC). Työssä ehdotetaan useita yhdistetyn verkko -ja kanavakoodauksen menetelmiä (JNCC), joissa log-uskottavuussuhdesekvenssit iteratiivisen purkamisprosessin aikana päivitetään hyödyntämällä sekvenssien riippuvuussuhdetta vastaanottimessa. Tämän tuloksena sekä bittivirhe- että kehysvirhesuhdetta saadaan parannettua verrattuna selektiiviseen pura-ja-lähetä menetelmää käyttävään MARC-strategiaan (SDF-MARC). Kehysvirheen suorituskyvyn tarkastelua varten työssä johdetaan teoreettinen epäkäytettävyyden todennäköisyys e-MARC-menetelmälle kahden lähettimen tapauksessa. Lisäksi e-MARC-menetelmälle määritetään tiedonsiirtonopeusalue Slepian-Wolf -teoreeman mukaisesti. Tämän jälkeen saadaan epäkäytettävyyden todennäköisyys kaikkien linkkien signaalikohinasuhteen todennäköisyystiheysfunktion integraalina tiedonsiirtonopeusalueen yli. Simulointitulokset osoittavat e-MARC-menetelmän paremman epäkäytettävyyden todennäköisyyden verrattuna SDF-MARC-menetelmään silloin kun yksi lähettimistä on kaukana sekä releestä että vastaanottimesta. Mahdollistaakseen useamman lähteen käytön e-MARC-menetelmässä, työssä ehdotetaan lisäksi adaptiivinen yhdistetyn verkko-ja kanavakoodauksen menetelmä (JANCC). Siinä vastaanotin määrittää väärin purettujen sekvenssien lähettimet ja ilmoittaa ne vektorimuodossa takaisin releelle pyytääkseen näiden lähettimien informaation uudelleenlähetystä. Tämän jälkeen rele suorittaa verkkokoodauksen vain tunnistusvektorin määrittämien informaatiosekvenssien estimaatteihin perustuen. Tulokset näyttävät, että JANCC-menetelmää käyttävä e-MARC saavuttaa paremman kehysvirheen ja hyödyllisen läpäisyn tehokkuuden verrattuna e-MARC-menetelmään
Veaux, Christophe. "Étude de traitements en réception pour l'amélioration de la qualité de la parole : application au GSM". Paris, ENST, 2005. http://www.theses.fr/2005ENST0006.
Pełny tekst źródłaIn digital mobile radio systems, the speech quality can be severly degraded if the channel decoder produces residual bit errors due to heavy burst errors on the radio path. On the other hand, in most speech coding schemes some residual redundancy remains because of complexity and delay limitations. A solution for improving the speech quality consists in using a priori information based on source residual redundancy at the receiver side. In one approach, a priori information is used at the source decoder to perform optimal estimation of transmitted codec parameters. In another approach, a priori information is used at the channel decoder in oder to minimize the residual bit errors rate. We study both approaches and apply them to the GSM EFR. At the speech decoder level, we model the residual redundancy of speech codec parameters by using Gaussian mixtures. This model reduces the complexity when compared to state-of-art methods and provides a better representation of residual redundancy. At the channel decoder level, we introduce an efficient method to exploit intra-frame bit redundancy during the channel decoding process. In this method, the value of the bit being decoded is predicted from the bits already decoded along the treillis path. These methods are evaluated on simulations of radio transmission by an objective measure of speech quality. In all cases, the performance of the speech decoder using our residual redundancy model turns out to be better than the GSM EFR decoder with standard error concealment procedure. The performance of the channel decoder using residual redundancy is strongly dependent of the index assignment used by the quantifier
Wernersson, Niklas. "Source-channel coding for wireless networks". Licentiate thesis, Stockholm : Communication Theory, School of Electrical Engineering, Royal Institute of Technology, 2006. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-3912.
Pełny tekst źródłaWernersson, Niklas. "Source-Channel Coding in Networks". Doctoral thesis, Stockholm : Communication Systems, Kommunikationssystem, Kungliga Tekniska högskolan, 2008. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-4751.
Pełny tekst źródłaBayramoglu, Muhammet Fatih. "Sub-graph Approach In Iterative Sum-product Algorithm". Master's thesis, METU, 2005. http://etd.lib.metu.edu.tr/upload/3/12606550/index.pdf.
Pełny tekst źródłaMhamdi, Maroua. "Méthodes de transmission d'images optimisées utilisant des techniques de communication numériques avancées pour les systèmes multi-antennes". Thesis, Poitiers, 2017. http://www.theses.fr/2017POIT2281/document.
Pełny tekst źródłaThis work is devoted to improve the coding/ decoding performance of a transmission scheme over noisy and realistic channels. For this purpose, we propose the development of optimized image transmission methods by focusing on both application and physical layers of wireless networks. In order to ensure a better quality of services, efficient compression algorithms (JPEG2000 and JPWL) are used in terms of the application layer enabling the receiver to reconstruct the images with maximum fidelity. Furthermore, to insure a transmission on wireless channels with a minimum BER at reception, some transmission, coding and advanced modulation techniques are used in the physical layer (MIMO-OFDM system, adaptive modulation, FEC, etc). First, we propose a robust transmission system of JPWL encoded images integrating a joint source-channel decoding scheme based on soft input decoding techniques. Next, the optimization of an image transmission scheme on a realistic MIMO-OFDM channel is considered. The optimized image transmission strategy is based on soft input decoding techniques and a link adaptation approach. The proposed transmission scheme offers the possibility of jointly implementing, UEP, UPA, adaptive modulation, adaptive source coding and joint decoding strategies, in order to improve the image visual quality at the reception. Then, we propose a robust transmission system for embedded bit streams based on concatenated block coding mechanism offering an unequal error protection strategy. Thus, the novelty of this study consists in proposing efficient solutions for the global optimization of wireless communication system to improve transmission quality
Ali, Usman. "WiBOX - Une passerelle pour une réception robuste de vidéo diffusée via WIMAX et une rediffusion indoor via WIFI". Phd thesis, Télécom ParisTech, 2010. http://pastel.archives-ouvertes.fr/pastel-00576262.
Pełny tekst źródłaJabaian, Bassam. "Systèmes de compréhension et de traduction de la parole : vers une approche unifiée dans le cadre de la portabilité multilingue des systèmes de dialogue". Phd thesis, Université d'Avignon, 2012. http://tel.archives-ouvertes.fr/tel-00818970.
Pełny tekst źródłaHatefi, Atoosa. "Distributed Coding for Wireless Cooperative Networks". Thesis, Supélec, 2012. http://www.theses.fr/2012SUPL0015/document.
Pełny tekst źródłaWith the rapid growth of wireless technologies, devices and mobile applications, the quest of high throughput and ubiquitous connectivity in wireless communications increases rapidly as well. Relaying is undoubtedly a key concept to provide coverage extension and capacity increase in wireless networks. Network coding, which allows the intermediate nodes to share their computation capabilities in addition to their resource and their power, has grabbed a significant research attention since its inception in information theory. It has become an attractive candidate to bring promising performance improvement, especially in terms of throughput, in relay-based cellular networks. Substantial research efforts are currently focused on theoretical analysis, implementation and evaluation of network coding from a physical layer perspective. The question is, what is the most efficient and practical way to use network coding in wireless relay-based networks, and whether it is beneficial to exploit the broadcast and multiple-access properties of the wireless medium to perform network coding. It is in such a context, that this thesis proceeds. In the first part of the thesis, the problem of Joint Network-Channel Coding (JNCC) for a Multiple Access Relay Channel (MARC) is investigated in the presence of multiple access interferences and for both of the relay operating modes, namely, half-duplex and full-duplex. To this end, three new classes of MARC, referred to as Half-Duplex Semi-Orthogonal MARC (HD-SOMARC), Half-Duplex Non-Orthogonal MARC (HD-NOMARC), and Full-Duplex Non-Orthogonal MARC (FD-NOMARC) have been introduced and studied. The relaying function in all of the classes is based on a Selective Decode-and-Forward (SDF) strategy, which is individually implemented for each source, i.e, the relay forwards only a deterministic function of the error-free decoded messages. For each class, an information-theoretic analysis is conducted, and practical coding and decoding techniques are proposed. The proposed coding schemes, perform very close to the outage limit for both cases of HD-SOMARC and HD-NOMARC. Besides, in the case of HD-NOMARC, the optimal allocation of the transmission time to the relay is considered. It is also verified that exploiting multiple access interferences, either partially or totally, results in considerable gains for MARC compared to the existing interference-avoiding structures, even in the case of single receive antenna. In the second part of the thesis, the network model is extended by considering multiple relays which help multiple sources to communicate with a destination. A new class of Multiple Access Multiple Relay Channel (MAMRC), referred to as Half-Duplex Semi-Orthogonal MAMRC (HD-SOMAMRC) is then proposed and analyzed from both information theoretic and code design perspective. New practical JNCC schemes are proposed, in which binary channel coding and non binary network coding are combined, and they are shown to perform very close to the outage limit. Moreover, the optimal allocation of the transmission time to the sources and relays is considered. Finally, in the third part of the thesis, different ways of implementing cooperation, including practical relaying protocols are investigated for the half-duplex MARC with semi-orthogonal transmission protocol and in the case of JNCC. The hard SDF approach is compared with two Soft Decode and Forward (SoDF) relaying functions: one based on log a posterior probability ratios (LAPPRs) and the other based on Mean Square Error (MSE) estimate. It is then shown that SDF works well in most of the configurations and just in some extreme cases, soft relaying functions (based on LAPPR or MSE estimate) can slightly outperform the hard selective one
Kim, Byung Hak. "Joint Equalization and Decoding via Convex Optimization". Thesis, 2012. http://hdl.handle.net/1969.1/ETD-TAMU-2012-05-10755.
Pełny tekst źródłaSamarawickrama, Upul. "Joint source-channel decoding of multiple descriptions". 2005. http://hdl.handle.net/1993/18097.
Pełny tekst źródłaHuang, Chun-Chia, i 黃俊嘉. "Content-aware Joint Video Retargeting and Decoding in Compressed Domain". Thesis, 2013. http://ndltd.ncl.edu.tw/handle/62965561984608106225.
Pełny tekst źródła國立中正大學
電機工程研究所
101
Since display devices have diverse resolution sizes and aspect ratios, videos are sometimes required to be resized before displaying on a variety of devise. Content-aware video retargeting technique aims to provide a better way than traditional simple cropping and uniform scaling which usually squeeze or discard the region which is less important and preserve the region of interest. Most existing retargeting algorithms work in the pixel domain. When a compressed video is sent from one device to the other device, decoding the bitstream to video sequence is first carried out and the video sequence is retargeted to desired size if the receiver has different resolution or aspect ratios. This work presents a method to retarget the compressed video in compressed domain where video decoding and retargeting are performed in one step. Experimental results show that the proposed method can save up to 60% computation times, compared to that of pixel-domain video retargeting. Furthermore, the retargeted video quality is also better than traditional uniform scaling.
Cruz, Susana Pereira Bulas. "Decoder design and decoding models for joint source-network coding". Dissertação, 2010. http://hdl.handle.net/10216/62125.
Pełny tekst źródłaLin, Zhi-Xian, i 林志賢. "Joint source-channel decoding for convolutionally encoded variable length codes". Thesis, 2012. http://ndltd.ncl.edu.tw/handle/52681082637156508108.
Pełny tekst źródła國立交通大學
電信工程研究所
100
Reliable transmission of convolutionally encoded source codec parameters over noisy channels can benefit from the use of joint source‐channel decoding (JSCD). This thesis focuses on the design of a symbol-based JSCD for convolutionally encoded variable‐length codes (VLC). We also investigate bidirectional decoding schemes by using reversible variable length code (RVLC). Our work starts with a sectionalized code trellis whose two-dimensional states are created by combing the symbol-based VLC trellis and the state transition of a channel encoder. Then, we derive the recursive implementation of JSCD algorithm according to the three-dimensional sectionalized code trellis. Simulation results on both Gauss-Markov sources and ECG signals demonstrate the error-resilience capabilities of symbol-based joint decoding by using the first-order source correlation.
Cruz, Susana Pereira Bulas. "Decoder design and decoding models for joint source-network coding". Master's thesis, 2010. http://hdl.handle.net/10216/62125.
Pełny tekst źródłaWu, Wei-I., i 吳威怡. "Bit- and Trellis- Based Joint Huffman and Convolutional Sequential Decoding Algorithms". Thesis, 2008. http://ndltd.ncl.edu.tw/handle/05464860396541934297.
Pełny tekst źródła國立暨南國際大學
資訊工程學系
96
According to the Shannon’s separation theory, the performance of the overall system is optimal while the source coding and the channel coding are separately optimized. However, due to the constraints on complexity and delay, the performance of separate decoding is usually not optimal. In the past, in order to further improve the performance of separate decoding, the residual redundancy left after compression, the source priori information, and the channel statictical information are exploited and fully utilized for presenting a so-called joint source-channel decoding (JSCD) scheme. In tradition, the trellis adopted in Viterbi decoding algorithm will become tremendously large while all the source and channel information are utilized. Although the decoding performance is optimal, the decoding complexity becomes quite expensive. Therefore, it is not practical. In this work, a new maximum a posteriori probability (MAP) metric with lower computational complexity is derived first, and then we propose a bit- and trellis- based jointly sequential decoding algorithm along with a suboptimal solution. Simulation results indicate the suboptimal method can provide nearly the same performance as optimal scheme while exhibiting a significantly lower complexity.
Tang, Fu-Qiao, i 湯復喬. "On Outage Analysis for Full-Duplex Relay Networks with Joint Decoding". Thesis, 2017. http://ndltd.ncl.edu.tw/handle/54st97.
Pełny tekst źródła國立中央大學
通訊工程學系
105
With the public demand for mobile data is increasing year by year, in the case of limited spectrum resources, how to improve the use of the spectrum becomes a hot topic. The full-duplex system has been widely discussed in recent years because of its capability in sending and receiving messages at the same time and the same frequency band, which is the system model adopted in this paper. This paper investigates the outage performance in full-duplex relay channel that adopts amplify-and-forward relay and decode-and-forward relay protocol. Previous works almost focused on that destination treated the self-interference signal as interference only. We provide a new system model which make self-interference signal assist information decoding at the destination, and we derived an approximate, yet accurate, closed-form expression for the end-to-end outage probability. In addition, the processing delay is larger than 1 in practice, the proposed close-form outage probability expression is still valid. Finally, we corroborate our theoretical results with simulations, the results indicate that the proposed system model can outperform traditional full-duplex and half-duplex systems.
Jing-ShiunLin i 林敬衒. "High-performance Joint Iterative Detection and Decoding Design in Coded-MIMO Systems". Thesis, 2015. http://ndltd.ncl.edu.tw/handle/92297209659102558260.
Pełny tekst źródła國立成功大學
電機工程學系
103
Multiple-input multiple-output (MIMO) techniques have been widely used to increase the transmission rate and improve the signal quality in modern wireless communication systems. To further ensure transmission reliability, error-correcting codes like turbo codes with performance close to the theoretical Shannon limit are adopted for wireless communication systems. Up to now, many MIMO detection algorithms have been proposed in the literature to recover the transmitted signals from the received noisy signals. In particular, soft-output MIMO detection algorithms can be used to provide a priori information of the codeword to the following soft-input soft-output (SISO) decoders, such as the turbo decoder in coded-MIMO systems. In some application scenarios with Rayleigh fading channels, the induced unreliable a priori information might result in system performance degradation. Exploring high-performance coded-MIMO systems thus becomes a challenging and crucial research area. In this dissertation, we have developed a high-performance joint iterative detection and turbo decoding design in coded-MIMO systems. First, a low-complexity high-throughput complex-valued QR factorization (CQRF) design is presented. Based on coordinate rotation digital computer (CORDIC) arithmetic, a massively parallel array architecture consisting of pipelined and folded CORDIC modules was developed to enhance the throughput. The chip implementation result indicates the design, with an equivalent gate count of 192.1K, can operate at 200 MHz and accomplish the highest 3-Gb/s data rate in 4×4 MIMO systems. The proposed design also outperforms related designs in two compound performance indices: data rate normalized with respect to gate count and power consumption. Second, we developed a mean-aided early-pruned scheme in MIMO detector based on sort-free fixed-complexity sphere decoding algorithm. The modified MIMO detector can reduce the number of node computations while maintaining the BER performance of the original sort-free algorithm. Experimental results show that the proposed reconfigurable detector design with 4×4 antenna array has a higher normalized throughput than those of existing detectors using the same system configuration. Third, an efficient joint iterative MIMO detection and turbo decoding design was developed. For the turbo decoding, a modified parallel-window MAP algorithm was proposed to reduce the warm-up computation. In the initial iteration, the reliability of the soft information of a MIMO detector can be greatly improved by applying the proposed extended tree search scheme. A modified updating strategy is presented to acquire the highly reliable extrinsic information from the soft-output MIMO detector in iterative system development. Compared to the list sphere decoding (LSD) algorithm, about 94% reduction in the memory requirement of log-likelihood ratio (LLR) computation can be achieved by using the proposed candidate node selection strategy. Finally, based on the analysis of iteration profile, the overall system performance can be maintained with a fewer number of searched nodes than existing works.
Onwuatuelo, Daniel Obinna. "Joint decoding of parallel power line communication and visible light communication systems". Thesis, 2018. https://hdl.handle.net/10539/26917.
Pełny tekst źródłaMany indoor applications operate at narrow band (3kHz148.5kHz) speed and for such applications, power line communication (PLC) and visible light communication (VLC) networks can be naturally connected and adapted to complement each other in order to gain more overall system performance in terms of bit error rate (BER) and computational complexity. In this research,the joint decoding of parallel PLC and VLC systems is proposed and its BER performance is compared to that of the PLCa nd the VLC systems. The joint decoding is applied either at the inner (Viterbi) or at the outer (Reed-Solomon) decoder. The proposed system is adopted according to the PLC G3 physical layer specification but direct current optical orthogonal frequency division multiplexing OFDM (DCO-OFDM) is used in the VLC system to ensure that only positive (unipolar) signals are transmitted. A realistic VLC channel model is adopted in this research by considering the VLC channel as an additive white Gaussian noise (AWGN) channel affected by attenuation in terms of angle of orientation between the source and the receiver and effective surface area of the receiver. Furthermore, the PLC channel is modeled as an AWGN channel with background and impulsive noise generated using Middleton Class Anoisedistributionmodel. Itisshownthroughsimulationresultsandanalysisthatthe proposed joint decoded system outperforms the PLC and the VLC systems in terms of BERperformancedependingonthedistanceofseparationbetweenthesourceandthe receiver. Key words: Power line communication (PLC), Visible light communication (VLC), Bit error rate (BER), Joint decoding, Orthogonal frequency division multiplexing (OFDM), DCopticalOFDM(DCO-OFDM),AdditivewhiteGaussiannoise(AWGN).
XL2019
Lin, Kai-Liang, i 林凱亮. "Study on Joint Detection and Decoding Algorithm Based on 5G NR Specification". Thesis, 2019. http://ndltd.ncl.edu.tw/handle/anza7p.
Pełny tekst źródła國立中山大學
通訊工程研究所
107
The fifth generation mobile network (5G), also known as New Radio (NR), is expected to be commercialized in 2020. The 5G NR operates including the sub-6GHz frequency bands and millimeter wave bands. In the non-standalone mode, the millimeter wave bands are operated with the aided by sub-6GHz bands. In the standalone mode, the sub-6GHz and the millimeter wave bands can be operated independently. Time Division Duplexing (TDD) mode is usually adopted in the standalone mode. Effectively operating the communications between base station and the user equipment in the TDD mode is a challenging issue. In order to measure the channel environments of different transmissions over the air, we developed a multi-input multi-output (MIMO) measurement platform for TDD mode. The platform mainly designs signal frame based on 5G NR specification, and we study ways to improve signal demodulation and decoding performance under limited bandwidth conditions, and pursue higher signal quality. We design a joint detection and decoding (JDD) algorithm in this thesis. The transmitted waveform adopts low-density parity check (LDPC) encoding based on 5G NR specification. At the receiver, the LDPC decoder feeds the output information bits back to the detector. JDD can sacrifice the cost of computational complexity for the reliability of information bits. JDD algorithm compare to the case without joint decoding, the effective signal noise ratio (ESNR) can be improved at least 3.29 dB. In order to further increase the efficiency of execution, LDPC decoder and detector use the architecture of single instruction multiple data (SIMD), which can increase online throughput. In this thesis, we design and simulate the JDD algorithm via channel, it can reduce systematic bit error rate. The JDD algorithm is also included into the TDD MIMO measurement platform. Through the over the air testing, we demonstrate that the JDD can reduce bit error rate, and can increase system throughput. Keywords: 5G NR, Joint Detection and Decoding, LDPC, MIMO, TDD.
Chao, Pi-Chung, i 趙必昌. "Joint Channel Estimation, Symbol Detection and LDPC Decoding in Time-Varying Fading Channels". Thesis, 2009. http://ndltd.ncl.edu.tw/handle/81878965891603577571.
Pełny tekst źródła國立交通大學
電信工程系所
97
An iterative receiver structure for joint channel estimation, symbol detection and channel decoding is proposed for the non-coherent decoding of the low-density parity check code in Rayleigh fading channels. Performance of the proposed algorithm is studied for both the flat and frequency-selective fading channels without using any pilot or training symbol. In flat fading channels, simulation results show that the performance of the non-coherent algorithm is only half decibel inferior to the coherent one, which matches the analysis using extrinsic information transfer chart, while in multiple fading channels, the performance gap against the coherent one is still large, which requires further investigations.
Chang, Yu-Hao, i 張育豪. "Generalized Piecewise Integer Mapping Based Arithmetic Coding and its Joint Source-Channel Decoding". Thesis, 2013. http://ndltd.ncl.edu.tw/handle/y2daq8.
Pełny tekst źródła國立暨南國際大學
資訊工程學系
101
Arithmetic coding (AC) is an efficient data compression technique and widely adopted in image and video compression standards. However, the high complexity of arithmetic coding in computation is the bottleneck that many researchers endeavor to overcome. Piecewise integer mapping based arithmetic coding can eliminate all multiplicative operations in both encoder and decoder by the technique of replacing them with the operations of comparison and addition. It can reduce the computational complexity with a little penalty of compression loss. A generalized piecewise integer mapping arithmetic coding can provide higher compression efficiency with maintaining almost the same coding speed. The iterative decoding to a communication scheme of which an arithmetic code with forbidden symbol is used for source coding and a recursive systematic convolutional code is used for channel coding. In this system, it adopts a low complexity SISO technique (called modified SOVA algorithm) for arithmetic coding, where arithmetic code can be modeled as a finite state machine and then can be decoded by using a trellis structure. Experimental results show that the piecewise integer mapping based AC or the generalized piecewise integer mapping based AC can not only eliminate all multiplicative operations to lower down the computational complexity, but also owns a little capability of error correcting. Besides, the compression efficiency of it sometime becomes better than that of the traditional integer AC. In general, the integer AC with forbidden symbol will outperform the integer AC without forbidden symbol in terms of the error correcting performance.Furthermore, the EXIT chart is also presented for analyzing the iterative decoding.
Huang, Chien-Hao, i 黃建豪. "Tree Search Based Configurable Joint Detection and Decoding Algorithms for MIMO Wireless Communications". Thesis, 2015. http://ndltd.ncl.edu.tw/handle/69645524744701606845.
Pełny tekst źródła國立臺灣科技大學
電子工程系
103
Multi Input Multi Output (MIMO) technology plays an essential role in modern wireless communication system owing to its capability to significantly improve communication quality and efficiency without drastically increasing the occupied bandwidth. However, such lucrative features also come along with the prominent drawback of significantly increased system complexity, especially on the receiver side. It has been shown that the Joint MIMO Detection and Channel Decoding (JDD) scheme can effectively reduce the complexity and improve the signal quality of the MIMO receiver. However, this previously proposed structure can only be applied with the system using specific code rate as well as modulation scheme such that it cannot be utilized in practical wireless system. In this thesis, we present the Configurable Joint Detection-Decoding (CJDD) scheme which can be used with several combinations of system settings and thus resolve the previous limitation. Moreover, since the JDD/CJDD approach is based on the tree search algorithms and there exists many different kinds of such methods with various characteristics, it is of great importance to understand the trade-offs between each tree search algorithm and their impacts on different aspects of system performances. In this thesis, we investigate three types of tree search algorithms: breadth-first based approach, depth-first based approach, and the Fano algorithm. We explore each of these algorithms on the basis of timing complexity, area complexity, and run-time variation. Our aim is to shed more lights on the design and application of tree search type approaches on the MIMO wireless communication systems for various needs of the system considerations.