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Konuskan, Cagatay. "Turbo Equalization for HSPA". Thesis, Linköping University, Department of Electrical Engineering, 2010. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-54640.
Pełny tekst źródłaNew high quality mobile telecommunication services are offered everyday and the demand for higher data rates is continuously increasing. To maximize the uplink throughput in HSPA when transmission is propagated through a dispersive channel causing self-interference, equalizers are used. One interesting solution, where the equalizer and decoder exchange information in an iterative way, for improving the equalizer performance is Turbo equalization.
In this thesis a literature survey has been performed on Turbo equalization methods and a chosen method has been implemented for the uplink HSPA standard to evaluate the performance in heavily dispersive channels. The selected algorithm has been adapted for multiple receiving antennas, oversampled processing and HARQ retransmissions. The results derived from the computer based link simulations show that the implemented algorithm provide a gain of approximately 0.5 dB when performing up to 7 Turbo equalization iterations. Gains up to 1 dB have been obtained by disabling power control, not using retransmission combining and utilizing a single receiver antenna. The algorithm has also been evaluated considering alternative dispersive channels, Log-MAP decoding, different code rates, number of Turbo equalization iterations and number of Turbo decoding iterations.
The simulation results do not motivate a real implementation of the chosen algorithm considering the increased computational complexity and small gain achieved in a full featured receiver system. Further studies are needed before concluding the HSPA uplink Turbo equalization approach.
Lee, Kah Ping. "Turbo equalization in wireless communication". Diss., Columbia, Mo. : University of Missouri-Columbia, 2005. http://hdl.handle.net/10355/5844.
Pełny tekst źródłaThe entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file. Title from title screen of research.pdf file viewed on (July 11, 2006) Includes bibliographical references.
Kurkoski, Brian M. "Algorithms and schedules for turbo equalization /". Diss., Connect to a 24 p. preview or request complete full text in PDF format. Access restricted to UC campuses, 2004. http://wwwlib.umi.com/cr/ucsd/fullcit?p3137222.
Pełny tekst źródłaMonfet, Frederic. "Turbo equalization using frequency-domain shortening filter". Thesis, McGill University, 2006. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=99527.
Pełny tekst źródłaMysore, Naveen. "Combined turbo coding and turbo equalization for wireless systems with antenna diversity". Thesis, McGill University, 2002. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=33983.
Pełny tekst źródłaThis thesis focuses on achieving reliable transmission over a class of multi-input multi-output Rayleigh faded channels at very low Signal-to-Noise Ratios (SNRs). The transmitter and receiver designs are based on turbo coding, multiple transmit/receive antennas and turbo equalization. Simulation studies were performed for systems with different coding rates, numbers of antennas and interleaving strategies. They show the ability to achieve small bit error rates (10-4--10-5) for negative values of SNR.
Oletu, Grace Ogheneruonano. "Turbo coding and equalization for wireless communication systems". Thesis, University of Greenwich, 2013. http://gala.gre.ac.uk/11626/.
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 źródłaChesnutt, Elizabeth. "Novel Turbo Equalization Methods for the Magnetic Recording Channel". Diss., Georgia Institute of Technology, 2005. http://hdl.handle.net/1853/6867.
Pełny tekst źródłaYildirim, Recep Ali. "Mmse Based Iterative Turbo Equalization For Antenna Switching Systems". Master's thesis, METU, 2010. http://etd.lib.metu.edu.tr/upload/12612480/index.pdf.
Pełny tekst źródłaFranz, Volker. "Turbo-detection for GSM-systems channel estimation, equalization and decoding /". [S.l. : s.n.], 2000. http://deposit.ddb.de/cgi-bin/dokserv?idn=96205772X.
Pełny tekst źródłaKansanen, K. (Kimmo). "Wireless broadband single-carrier systems with MMSE turbo equalization receivers". Doctoral thesis, University of Oulu, 2005. http://urn.fi/urn:isbn:9514279336.
Pełny tekst źródłaOtnes, Roald. "Improved Receivers for Digital High Frequency Communications : Iterative Channel Estimation, Equalization, and Decoding (Adaptive Turbo Equalization)". Doctoral thesis, Norwegian University of Science and Technology, Faculty of Information Technology, Mathematics and Electrical Engineering, 2002. http://urn.kb.se/resolve?urn=urn:nbn:no:ntnu:diva-86.
Pełny tekst źródłaWe address the problem of improving the throughput and the availability of digital communications in the High Frequency (HF, 3-30 MHz) band. In standardized military waveforms, the data is protected by an error-correcting code (ECC), and the code bits are shuffled by an interleaver and mapped onto a signal constellation for modulation onto a single carrier. Training sequences are multiplexed into the stream of transmitted symbols to aid the receiver in tracking the channel variations. The channel imposes severe time-varying intersymbol interference (ISI) as well as additive noise. Conventional receivers for such a system would first perform adaptive equalization (to mitigate the ISI) and symbol demapping, deinterleave the received code bits, and finally perform decoding, where the redundancy of the ECC is used to make high-quality decisions on the transmitted data bits even when bit errors have been introduced by the channel. Such a receiver is suboptimal because the equalizer does not make use of the redundancy introduced by the ECC, and is outperformed by an iterative scheme called turbo equalization. In turbo equalization, a.k.a. iterative equalization and decoding, soft information on the code bits is fed back from the decoder to the equalizer in an iterative fashion, and by performing the equalization and decoding tasks several times the bit error rates become significantly smaller than for a conventional “single-pass” receiver. Since we are dealing with an unknown time-varying channel, we must also perform channel estimation. We include channel estimation in the iterative loop of the turbo equalizer, using soft information fed back from the decoder as “training sequences” between the ordinary transmitted training sequences. Then, the receiver performs iterative channel estimation, equalization, and decoding, which can also be called adaptive turbo equalization. We have proposed a receiver using adaptive turbo equalization, and performed simulations using the MIL-STD-188-110 waveform at 2400 bps, transmitted over an ITU-R poor channel (a commonly used channel to test HF modems). We find that the proposed receiver outperforms a conventional receiver by 2-3 dB in terms of required signal-to-noise ratio to achieve a certain bit error rate. In this dissertation, we give an introduction to the fields of HF communications and standardized HF waveforms, channel modelling, and turbo equalization. We present an analysis of measured channel data to motivate our research in turbo equalization. We then present our research contributions to the field of turbo equalization: A low-complexity soft-in soft-out equalizer for time-varying channels, a comparative study of channel estimation algorithms using soft information as the input signal, and an investigation of adaptive turbo equalization using a technique known as EXIT charts. Finally, we present our main practical result, which is our proposed receiver and the corresponding simulation results.
Karjalainen, J. (Juha). "Broadband single carrier multi-antenna communications with frequency domain turbo equalization". Doctoral thesis, Oulun yliopisto, 2011. http://urn.fi/urn:isbn:9789514295027.
Pełny tekst źródłaTiivistelmä Tässä työssä tutkitaan edistyksellisten moniantennivastaanotto- ja lähetysmenetelmien käyttöä radioresurssien tehokkuuden parantamiseen laajakaistaisessa yhden kantoaallon kommunikaatiossa. Työssä keskitytään erityisesti laskennallisesti tehokkaiden taajuustasossa suoritettavien iteratiivisten kanavakorjaintekniikoiden kehittämiseen yhden ja usean käyttäjän multiple-input multiple-output (MIMO) -kommunikaatiossa taajuusselektiivisen radiokanavan yli. Toinen tutkimuksen painopiste on lähetystehon optimointi yhden käyttäjän MIMO-kommunikaatiossa, jossa iteratiivisen kanavakorjaimen konvergenssiominaisuudet otetaan huomioon. Työssä ehdotetaan uudenlaista iteratiivista taajuustasossa suoritettavaa soft-cancellation (SC) ja minimum mean square error (MMSE) -suodatukseen pohjautuvaa joint-over-antenna (JA) monen käyttäjän ilmaisumenetelmää nousevan siirtokanavan tiedonsiirtoon taajuusselektiivisessa radiokanavassa. Ehdotettu tajuustasossa suoritettava usean käyttäjän MIMO-lähetyksen ilmaisumenetelmä vaatii selvästi vähemmän laskentatehoa verrattuna aikatason menetelmään. Tämän lisäksi ehdotetulla menetelmällä voidaan saavuttaa merkittävää suorituskykyhyötyä verrattuna antenna-by-antenna (AA) -pohjaiseen iteratiiviseen vastaanottimeen kun lähetysantennien ja käyttäjien kokonaislukumäärä on suurempi kuin vastaanotinantennien. Suorituskykyhyöty pätee myös tilakorrelaation tapauksessa. Työssä tutkitaan lisäksi olemassa olevien lineaaristen esikoodaustekniikoiden, esim. maximum information rate (MaxRate) and minimum sum mean square error (MinSumMSE), vaikutusta taajuustasossa suoritettavaan iteratiivisen kanavakorjaimen konvergenssiominaisuuksiin xtrinsic information transfer (EXIT) -analyysin avulla. Työssä ehdotetaan uudenlaista EXIT-analyysi-pohjaista lähetystehon minimointimenetelmää yhden kantoaallon MIMO-lähetykseen käyttäen iteratiivista taajuustason SC-MMSE-kanavakorjainta. Menetelmä ottaa huomioon iteratiivisen kanavakorjaimen konvergenssiominaisuudet. Ehdotettu convergence constrained power allocation (CCPA) -menetelmä erottaa tilatason häiriön lähetteiden välillä hyödyntäen singular value decomposition (SVD) -tekniikkaa ja minimoi lähetystehon ja saavuttaa samalla keskinäisinformaatiotavoitteet jokaiselle lähetteelle iteraatioiden jälkeen vastaanottimessa. Lähetystehon minimointiongelma voidaan muotoilla konveksiksi optimointiongelmaksi. Kahden keskinäisinformaatiorajoitteen erityistapaukselle johdetaan Lagrangen duaalifunktio ja ratkaistaan sen duaalifunktio. Työssä kehitetään lisäksi kaksi CCPA-pohjaista heuristista menetelmää. Numeeriset tulokset osoittavat ehdotettujen CCPA-pohjaisten menetelmien suoriutuvan paremmin verrattuna olemassa oleviin menetelmiin
Iltis, Ronald A. "Decoding and Turbo Equalization for LDPC Codes Based on Nonlinear Programming". International Foundation for Telemetering, 2010. http://hdl.handle.net/10150/605945.
Pełny tekst źródłaDecoding and Turbo Equalization (TEQ) algorithms based on the Sum-Product Algorithm (SPA) are well established for LDPC codes. However there is increasing interest in linear and nonlinear programming (NLP)-based decoders which may offer computational and performance advantages over the SPA. We present NLP decoders and Turbo equalizers based on an Augmented Lagrangian formulation of the decoding problem. The decoders update estimates of both the Lagrange multipliers and transmitted codeword while solving an approximate quadratic programming problem. Simulation results show that the NLP decoder performance is intermediate between the SPA and bit-flipping algorithms. The NLP may thus be attractive in some applications as it eliminates the tanh/atanh computations in the SPA.
Le, Bidan Raphaël. "Turbo-equalization for bandwidth-efficient digital communications over frequency-selective channels". Rennes, INSA, 2003. http://www.theses.fr/2003ISAR0012.
Pełny tekst źródłaDoan, Dung Ngoc. "Design and analysis of iteratively decodable codes for ISI channels". Diss., Texas A&M University, 2004. http://hdl.handle.net/1969.1/2754.
Pełny tekst źródłaIltis, Ronald A. "Turbo Equalization for OFDM over the Doubly-Spread Channel using Nonlinear Programming". International Foundation for Telemetering, 2011. http://hdl.handle.net/10150/595779.
Pełny tekst źródłaOFDM has become the preferred modulation format for a wide range of wireless networks including 802.11g, 802.16e (WiMAX) and 4G LTE. For multipath channels which are time-invariant during an OFDM symbol duration, near-optimal demodulation is achieved using the FFT followed by scalar equalization. However, demodulating OFDM on the doubly-spread channel remains a challenging problem, as time-variations within a symbol generate intercarrier interference. Furthermore, demodulation and channel estimation must be effectively combined with decoding of the LDPC code in the 4G-type system considered here. This paper presents a new Turbo Equalization (TEQ) decoder, detector and channel estimator for OFDM on the doubly-spread channel based on nonlinear programming. We combine the Penalty Gradient Projection TEQ with a MMSE-type channel estimator (PGP-TEQ) that is shown to yield a convergent algorithm. Simulation results are presented comparing conventional MMSE TEQ using the Sum Product Algorithm (MMSE-SPA-TEQ) with the new PGP-TEQ for doubly-spread channels.
Fuchs-Lautensack, Martin. "Advances in multi-user scheduling and turbo equalization for wireless MIMO systems". Ilmenau ISLE, 2009. http://d-nb.info/995974241/04.
Pełny tekst źródłaAssegu, Wannaw, i Ibrahim Fofanah. "Performance of Turbo Coded OFDM Modulation over an Aeronautical Channel". International Foundation for Telemetering, 2012. http://hdl.handle.net/10150/581818.
Pełny tekst źródłaSilva, Fábio José. "Design and performance evaluation of turbo FDE receivers". Master's thesis, Faculdade de Ciências e Tecnologia, 2010. http://hdl.handle.net/10362/4975.
Pełny tekst źródłaIn recent years, block transmission techniques were proposed and developed for broadband wireless communication systems, which have to deal with strongly frequency-selective fading channels. Techniques like Orthogonal Frequency-Division Multiplexing (OFDM)and Single Carrier with Frequency Domain Equalization (SC-FDE) are able to provide high bit rates despite the channel adversities. In this thesis we concentrate on the study of single carrier block transmission techniques considering receiver structures suitable to scenarios with strongly time-dispersive channels. CP-assisted (Cycle Pre x) block transmission techniques are employed to cope with frequency selective channels, allowing cost-e ective implementations through FFT-based (Fast Fourier Transform) signal processing. It is investigated the impact of the number of multipath components as well as the diversity order on the asymptotic performance of SC-FDE schemes. We also propose a receiver structure able to perform a joint detection and channel estimation method, in which it is possible to combine the channel estimates, based on training sequences, with decision-directed channel estimates. A study about the impact of the correlation factor estimation in the performance of Iterative Block-Decision Feedback Equalizer (IB-DFE) receivers is also presented.
Fuchs-Lautensack, Martin [Verfasser]. "Advances in multi-user scheduling and turbo equalization for wireless MIMO systems / Martin Fuchs-Lautensack.ISLE". Ilmenau : ISLE, 2009. http://d-nb.info/99975128X/34.
Pełny tekst źródłaWavegedara, Kapila Chandika B. "Advanced receivers for space-time block-coded single-carrier transmissions over frequency-selective fading channels". Thesis, University of British Columbia, 2008. http://hdl.handle.net/2429/620.
Pełny tekst źródłaTamma, Raja Venkatesh. "Iterative equalization and decoding using reduced-state sequence estimation based soft-output algorithms". Texas A&M University, 2004. http://hdl.handle.net/1969.1/283.
Pełny tekst źródłaMinkov, Lyubomir L. "EXPERIMENTAL DEMONSTRATION OF MITIGATION OF LINEAR AND NONLINEAR IMPAIRMENTS IN FIBER-OPTIC COMMUNICATION SYSTEMS BY LDPC-CODED TURBO EQUALIZATION". Diss., The University of Arizona, 2009. http://hdl.handle.net/10150/194082.
Pełny tekst źródłaGroßmann, Marcus [Verfasser], Reiner [Akademischer Betreuer] Thomä, Volker [Akademischer Betreuer] Kühn i Werner [Akademischer Betreuer] Teich. "Transmission strategies for broadband wireless systems with MMSE turbo equalization / Marcus Großmann. Gutachter: Volker Kühn ; Werner Teich. Betreuer: Reiner Thomä". Ilmenau : Universitätsbibliothek Ilmenau, 2012. http://d-nb.info/1065829183/34.
Pełny tekst źródłaGroßmann, Marcus Verfasser], Reiner [Akademischer Betreuer] [Thomä, Volker [Akademischer Betreuer] Kühn i Werner [Akademischer Betreuer] Teich. "Transmission strategies for broadband wireless systems with MMSE turbo equalization / Marcus Großmann. Gutachter: Volker Kühn ; Werner Teich. Betreuer: Reiner Thomä". Ilmenau : Universitätsbibliothek Ilmenau, 2012. http://nbn-resolving.de/urn:nbn:de:gbv:ilm1-2012000014.
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 źródłaCharaf, Akl. "Etudes de récepteurs MIMO-LDPC itératifs". Phd thesis, Télécom ParisTech, 2012. http://pastel.archives-ouvertes.fr/pastel-00913457.
Pełny tekst źródłaAbelló, Barberán Albert. "Turbo égalisation à haute performance pour la transmission par satellite au-delà de la cadence de Nyquist". Thesis, Toulouse, ISAE, 2018. http://www.theses.fr/2018ESAE0025/document.
Pełny tekst źródłaIn order to increase the spectral efficiency of digital communications systems,the faster-than-Nyquist (FTN) approach increases the symbol rate beyond the occupied bandwidthof the transmitted signal independently of the constellation type and size. It has beenshown that information rates of FTN systems are greater than those of Nyquist systems.However, the non-compliance of the Nyquist criterion causes inter-symbol interference to appearand therefore appropriate reception techniques must be used. At reception, the channelshortening approach consists on a receiving filter followed by a BCJR algorithm computingapproximate a posteriori symbol probabilities by considering a modified channel response ofreduced length. In the literature, the channel shortening receiving filters are chosen to maximizethe generalized mutual information (GMI). Such optimization is performed by usingnumerical optimization methods. In this PhD thesis, we propose a closed-form solution forall channel shortening filters considering the GMI maximization criterion. We show that theminimum mean square error (MMSE) equalizer is a particular case of the channel shorteningapproach. Within the frame of turbo equalization, we then study a suitable estimator allowingto obtain symbols a priori information from the information provided by the a decoder. Finally,we study the performance of the complete system with channel coding over an additivewhite Gaussian noise channel
Deleu, Thibault. "Digital predistortion and equalization of the non-linear satellite communication channel". Doctoral thesis, Universite Libre de Bruxelles, 2014. http://hdl.handle.net/2013/ULB-DIPOT:oai:dipot.ulb.ac.be:2013/209212.
Pełny tekst źródłaDoctorat en Sciences de l'ingénieur
info:eu-repo/semantics/nonPublished
Nhan, Nhat-Quang. "Optimisation de précodeurs linéaires pour les systèmes MIMO à récepteurs itératifs". Thesis, Brest, 2016. http://www.theses.fr/2016BRES0062/document.
Pełny tekst źródłaThe long-term evolution (LTE) and the LTE-Advanced (LTE-A) standardizations are predicted to play essential roles in the future fifth-generation (5G) mobile networks. These standardizations require high data rate and high quality of service, which assures low error-rate and low latency. Besides, as discussed in the recent surveys, low complexity communication systems are also essential in the next 5G mobile networks. To adapt to the modern trend of technology, in this PhD thesis, we investigate the multiple-input multiple-output (MIMO) wireless communication schemes. In the first part of this thesis, low-complex forward error correction (FEC) codes are used for low complexity and latency. By considering iterative receivers at the receiver side, we exploit MIMO linear precoding and mapping methods to optimize the error-rate performance of these systems. In the second part of this thesis, non-binary low density parity check (NB-LDPC) codes are investigated. We propose to use MIMO precoders to reduce the complexity for NB-LDPC encoded MIMO systems. A novel low complexity decoding algorithm for NB-LDPC codes is also proposed at the end of this thesis
Gazi, Orhan. "Parallelized Architectures For Low Latency Turbo Structures". Phd thesis, METU, 2007. http://etd.lib.metu.edu.tr/upload/12608110/index.pdf.
Pełny tekst źródłaGulmez, Baskoy Ulku. "A Turbo Detection Scheme For Egprs". Master's thesis, METU, 2003. http://etd.lib.metu.edu.tr/upload/1259415/index.pdf.
Pełny tekst źródłaso suboptimum schemes have to be considered. The Delayed Decision Feedback Sequence Estimation (DDFSE) is chosen as suboptimal and less complex trellis based scheme and it is examined as a conventional equalization technique firstly. It is shown that the DDFSE has a fine tradeoff between performance and complexity and can be a promising candidate for EGPRS. Then it is employed to reduce the number of the trellis state in turbo detection. Max-log-MAP algorithm is used for soft output calculations of both SISO equalizer and SISO decoder. Simulation results illustrate that proposed turbo detection structure improves bit error rate and block error rate performance of the receiver with respect to the conventional equalization and decoding scheme. The iteration gain varies depending on modulation type and coding rate of Modulation Coding Scheme (MCS) employed in EGPRS.
Arthur, Rangel 1977. "Novas propostas para otimização de receptores de TV digital baseados em OFDM em ambientes de redes de frequencia unica regionais". [s.n.], 2007. http://repositorio.unicamp.br/jspui/handle/REPOSIP/261230.
Pełny tekst źródłaTese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia Eletrica e de Computação
Made available in DSpace on 2018-08-08T10:21:08Z (GMT). No. of bitstreams: 1 Arthur_Rangel_D.pdf: 3675976 bytes, checksum: 65350df75e5a9588b1366325ac95ef62 (MD5) Previous issue date: 2007
Resumo: Esta tese trata da otimização de receptores de TV Digital baseados em OFDM, com avaliação de desempenho em redes de retransmissão em freqüência única (SFN . Single Frequency Networks) regionais. Tal ambiente facilita a distribuição de canais, porém possui características que dificultam o trabalho do receptor. São tratados, inicialmente, de projetos de filtros canceladores de elos de realimentação em estações retransmissoras, que ocorrem quando a antena de transmissão interfere na antena de recepção. Um novo filtro, baseado em técnicas que utilizam informação temporal é proposto. Novas propostas são feitas para as partes de sincronismo, estimação e equalização de canal, e codificação/decodificação. Uma técnica, vinda da teoria de reconhecimento de padrões, é aplicada para diminuição da complexidade no processo de sincronismo temporal. Um sistema de estimação de canal 2D e equalização adaptativa, usando o LMS (Least Mean Square), é comparado com técnicas clássicas da literatura, e um ganho significativo é encontrado. Como novo esquema de codificação e decodificação é proposto um esquema iterativo, baseado em códigos turbo, com número reduzido de iterações. Tal código melhora o desempenho do sistema em relação ao uso combinado dos decodificadores Viterbi e Reed Solomon. Todas as propostas são combinadas para se avaliar o desempenho do receptor diante de condições típicas de SFN e multicaminhos típicos em recepção de TV do Brasil
Abstract: This thesis deals with the optimization of Digital TV receivers based on OFDM, with performance evaluation in regional single frequency networks (SFN). Such environment facilitates the channel distribution, however its characteristics degrade the receiver operation. Initially, projects of loop canceller filters in relay stations are treated, and they are necessary when the transmission antenna causes interference on reception antenna. A new filter, based on time information is proposed. New proposals are made for the synchronism, channel estimation and equalization, and coding/decoding. One technique, coming from the pattern recognition theory, is applied for complexity reduction in the process of time synchronism. A 2D channel estimation system and adaptive equalization, using LMS (Least Mean Square), is compared to classical techniques in the literature, and a significant gain is achieved. As a new coding and decoding scheme, an iterative system based on turbo codes is used with reduced number of iterations. Such code improves the system performance when compared to the Viterbi and Reed Solomon concatenated decoders. The proposals are combined and the performance of the proposed receiver is evaluated on typical conditions of SFN and on typical multipaths for TV reception in Brazil
Doutorado
Telecomunicações e Telemática
Doutor em Engenharia Elétrica
Charaf, Akl. "Etudes de récepteurs MIMO-LDPC itératifs". Electronic Thesis or Diss., Paris, ENST, 2012. http://www.theses.fr/2012ENST0017.
Pełny tekst źródłaThe aim of this thesis is to address the design of iterative MIMO receivers using LDPC Error Correcting codes. MIMO techniques enable capacity increase in wireless networks with no additional frequency ressources. The associationof MIMO with multicarrier modulation techniques OFDM made them the cornerstone of emerging high rate wireless networks. Optimal reception can be achieved using joint detection and decoding at the expense of a huge complexity making it impractical. Disjoint reception is then the most used. The design of iterative receivers for some applications using LDPC codes like Wifi (IEEE 802.11n) is constrained by the standard code structure which is not optimized for such kind of receivers. By observing the effect of the number of iterations on performance and complexity we underline the interest of scheduling LDPC decoding iterations and turboequalization iterations. We propose to define schedules for the iterative receiver in order to reduce its complexity while preserving its performance. Two approaches are used : static and dynamic scheduling. The second part of this work is concerns Multiuser MIMO using Spatial Division Multiple Access. We explore and evaluate the interest of using iterative reception to cancel residual inter-user interference
Hwang, Sung Jun. "Communication over Doubly Selective Channels: Efficient Equalization and Max-Diversity Precoding". The Ohio State University, 2010. http://rave.ohiolink.edu/etdc/view?acc_num=osu1261506237.
Pełny tekst źródłaLahbabi, Naila. "Faster than Nyquist transceiver design : algorithms for a global transmission-reception enhancement". Thesis, Ecole nationale supérieure Mines-Télécom Atlantique Bretagne Pays de la Loire, 2017. http://www.theses.fr/2017IMTA0017/document.
Pełny tekst źródłaThe exponential growth of wireless data traffic driven by mobile Internet and smart devices constrains the future radio systems to include advanced modulations/waveforms offering higher data rates with more efficient bandwidth usage. One possibility is to violate the well known Nyquist criterion by transmitting faster than the Nyquist rate, i.e., using a technique also known as Faster-Than-Nyquist (FTN) signaling. Nyquist-based systems have the advantage of simple transmitter and receiver architectures at the detriment of bandwidth efficiency. The idea of signaling beyond the Nyquist rate to trade the interference-free transmission for more throughput goes back to 1975. In this dissertation, we investigate the concept of FTN signaling over Additive White Gaussian Noise (AWGN) channel in the context of Orthogonal Frequency Division Multiplexing with Offset Quadrature Amplitude Modulation OFDM/OQAM modulation.The main objective of our work is to present an OFDM/OQAM system signaling faster than the Nyquist one and explore its potential rate improvement while keeping under consideration the overall system complexity. First, we propose a new efficient FTN implementation of OFDM/OQAM systems, denoted by FTN-OQAM, that has the same complexity as OFDM/OQAM systems, while approaching very closely the FTN theoretical rate improvement. As the Nyquist condition is no longer respected, severe interference impacts the transmitted signals. To deal with the introduced interferences, we propose a turbo-like receiver based on Minimum Mean Square Error Linear Equalization and Interference Cancellation, named MMSE LE-IC. The aim of our system is to boost the transmission rate, which means that high constellation orders will be targeted. In this respect, the MMSE LE-IC, whose complexity is independent of the constellation, turns out to be a good candidate. Since OFDM/OQAM modulation can be equipped with different types of pulse shapes, we propose an algorithm to find, for different constellation orders, the minimum achieved FTN packing factor for various pulse shapes. Then, we aim at improving the iterative processing of the introduced transceiver. The proposed method involves combining a precoder with the FTN-OQAM system in order to remove FTN-induced interference at the transmitter. We also present a sparse precoding pattern as it is difficult to jointly precode all the transmitted symbols. We introduce three families of precoders along with the corresponding receivers. Furthermore, we propose several modifications of the FTN-OQAM transmitter concerning different blocks such as channel coding, bits mapping and symbols mapping to further enhance the FTN-OQAM transceiver design. Presented results reveal the significant potential of the proposed methods
Nayak, Aravind Ratnakar. "Iterative Timing Recovery for Magnetic Recording Channels with Low Signal-to-Noise Ratio". Diss., Georgia Institute of Technology, 2004. http://hdl.handle.net/1853/5018.
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 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 źródłaPetit, Paul. "Turbo-equalization for QAM constellations". 2002. http://arrow.unisa.edu.au:8081/1959.8/46699.
Pełny tekst źródłaLin, Yung-Che, i 林雍哲. "Minimum Delay Scheduling for Turbo Equalization with Turbo Codes". Thesis, 2008. http://ndltd.ncl.edu.tw/handle/r2j536.
Pełny tekst źródła國立高雄第一科技大學
電子與資訊工程研究所
96
The traditional turbo equalization basically is composed by a equalization series a Error-Correcting Codes decoder. When low SNR, the EXIT chart that the convergence tunnel to be unable to open, and the bit error rate can display not good. Above question can be solved effectively if the turbo equalization union turbo code( hereafter refers to as the double turbo equalization). Different the traditional turbo equalization, the double turbo equalization is a kind of turbo signal processor merges three soft processes which decoding way is complex and non-only. How to find the best decoding way, according to all kinds of demand is an interesting and important question. Brannstrom succeeded proposed the optimal scheduling of decoding way under the restriction that can only start a soft processor in once. Based on real time and the demand of high speed communication, how to find the minimum delay decoding way is an important subject and still a question not solved so far. Brannstrom’s proposed the best decoding way which has not still achieved the minimum delay and still had reduces the detention the space, due to the restriction can only start a soft processor in once. In this article, we have relaxed the limit of starting the number of the soft processor, and changes advance route of the double turbo equalization on the three domain EXIT chart, and proposed one kind of scheduling of minimum delay decoding way which be suitable for the double turbo equalization. The simulation result showed that, we proposed minimum delay scheduling can achieve restrains shorter than Brannstrom’s optimal scheduling. In turbo equalization union parallel (seriers) turbo code configuration, our method may effective reduce 12.5% (15%) delay time, when Es/No is equal 2dB(2.2dB) at a bit-error rate of 10-2.
Lin, Yu-Cheng, i 林育丞. "Turbo Equalization And Turbo coding for MIMO-OFDM System". Thesis, 2007. http://ndltd.ncl.edu.tw/handle/xr5qu7.
Pełny tekst źródła國立交通大學
電信工程系所
95
In this thesis, we focus on the outer receiver design for multiple-input-multiple output (MIMO) OFDM systems. The outer receiver mainly consists of a soft-bit demapper and an outer code decoder. The conventional approach considers these two devices separately, and cannot achieve true optimum performance. In the first part of the thesis, we study the application of turbo equalization technique in MIMO-OFDM systems. Using this approach, we can combine demapping and decoding in an iterative way. The conventional communication system often uses the bit-interleaved-coding modulation (BICM) scheme. However, the BICM scheme treats coding and modulation separately, and does not exploit the MIMO structure constraint. Tone-interleaved- coding-modulation (TICM) has been proposed to solve the problem. However, only the convolution code was considered. In the second part of the thesis, we propose to use the turbo code in the TICM scheme. Simulations with the IEEE 802.11n systems show that both the turbo equalization and the TICM schemes can significantly outperform conventional approaches.
Myburgh, Hermanus Carel. "Low complexity turbo equalization using superstructures". Thesis, 2013. http://hdl.handle.net/2263/32814.
Pełny tekst źródłaThesis (PhD)--University of Pretoria, 2013.
gm2013
Electrical, Electronic and Computer Engineering
unrestricted
Gaffar, Mohammed Yusuf Abdul. "MMSE equalizers and precoders in turbo equalization". Thesis, 2003. http://hdl.handle.net/10413/4155.
Pełny tekst źródłaThesis (M.Sc.Eng.)-University of Natal, Durban, 2003.
Zhang, Yuan-Kai, i 張廖元凱. "Low-complexity Fuzzy-Filter-Assisted Turbo Equalization". Thesis, 2005. http://ndltd.ncl.edu.tw/handle/87428896228596257666.
Pełny tekst źródła國立雲林科技大學
電子與資訊工程研究所
93
Turbo equalizer (TEQ) was shown to against inter symbol interference (ISI) and multipath Rayleigh fading channel effective. That had been implement using linear filter, Logarithm-Maximum a-posteriori algorithm (Log-MAP), Soft Output Viterbi algorithm (SOVA), and Radial Basis Function algorithm (RBF). In RBF-TEQ, which has high computational complexity, in order to reduce computational complexity, we can use Jacobian logarithmic algorithm and Decision-feedback technology, but in high order equalizer, the number of adder is exponential increase, so the computational complexity still too high for materializing. In this paper, we present fuzzy algorithm to reduce computational complexity. We joint fuzzy-filter equalizer and log-MAP decoder (Fuzzy-TEQ). The fuzzy equalizer is shown to perform close to the Bayesian equalizer (RBF). Using different membership function, we get different performance. However, in first iteration, the RBF-TEQ performance is better than Fuzzy-TEQ . After several iteration, the fuzzy-TEQ just need increase one iteration, the performance will be very close RBF-TEQ, almost same performance, but computational complexity can be reducing effective.
"Turbo equalization and turbo estimation for multiple-input multiple-output wireless systems". Université catholique de Louvain, 2006. http://edoc.bib.ucl.ac.be:81/ETD-db/collection/available/BelnUcetd-09112006-173121/.
Pełny tekst źródłaPeng, Jun-Hua, i 彭俊豪. "Combination of Turbo Trellis Coded Modulation and Turbo Equalization for Wireless Communication". Thesis, 2007. http://ndltd.ncl.edu.tw/handle/81534015190901259784.
Pełny tekst źródła國立臺灣科技大學
電子工程系
95
Because of the rapid and widespread development of communication technique, transmission style has developed from wire communication to wireless communication. Wireless communication has become a popular topic in recent mobile communication. It is necessary that we apply channel equalization and channel coding techniques in data transmission when we transmit data in multi-path fading channels, which typically suffer serious signal degradation. In this thesis, we consider an iterative system, turbo equalization, which consists of equalization and decoding. Finally, the performances of these techniques mentioned above are evaluated by computer simulation in multi-path fading channels In the part of channel coding, turbo trellis-coded modulation is considered. Encoded signals are transmitted in wireless fading channel; we employ turbo equalization, which consists of trellis equalizer and decoder in the receiver. The form of equalizer is not the same as the form of decoder. Because the forms of exchange of extrinsic information for equalizer and decoder in different forms, we have to use some methods to help transfer the extrinsic information as each other’s soft-input information. Because the computation load of equalizer is high, we also try to use T-BCJR algorithm to reduce the computation complexity of equalizer.
"Combating channels with long impulse response using combined turbo equalization and turbo decoding". 2000. http://library.cuhk.edu.hk/record=b5890402.
Pełny tekst źródłaThesis (M.Phil.)--Chinese University of Hong Kong, 2000.
Includes bibliographical references (leaves 56-[59]).
Abstracts in English and Chinese.
Chapter 1 --- Introduction --- p.1
Chapter 1.1 --- Communications and Coding Technology --- p.2
Chapter 1.2 --- The Emerge of Turbo Codes --- p.3
Chapter 1.3 --- The Extension of Turbo Principle --- p.3
Chapter 1.4 --- Receiver Structures for Practical Situations --- p.4
Chapter 1.5 --- Thesis Overview --- p.5
Chapter 2 --- ISI Channel Model and Channel Equalization --- p.6
Chapter 2.1 --- A Discrete Time ISI Channel Model --- p.6
Chapter 2.1.1 --- Optimum Maximum Likelihood Receiver --- p.8
Chapter 2.1.2 --- The Whitened Matched Filter --- p.11
Chapter 2.2 --- Equalization Techniques for Combating ISI --- p.13
Chapter 2.2.1 --- Linear MMSE Equalizer --- p.13
Chapter 2.2.2 --- MLSE Equalizer in Viterbi Algorithm --- p.15
Chapter 3 --- An Overview of Turbo Codes --- p.18
Chapter 3.1 --- The Turbo Encoder --- p.19
Chapter 3.2 --- The Turbo Interleaver --- p.21
Chapter 3.3 --- The Iterative Decoder --- p.22
Chapter 3.3.1 --- The MAP Algorithm --- p.23
Chapter 3.3.2 --- The Max-Log MAP Algorithm --- p.25
Chapter 3.3.3 --- The Log-MAP Algorithm --- p.28
Chapter 4 --- Receivers for Channels with Long Impulse Responses --- p.29
Chapter 4.1 --- Shortcomings for the Existing Models --- p.30
Chapter 4.2 --- Proposed System Architecture --- p.30
Chapter 4.2.1 --- Optimized Model for Channel Shortening Filter --- p.31
Chapter 4.2.2 --- Method One - Separate Trellises for EQ and DEC --- p.35
Chapter 4.2.3 --- Method Two - Combined Trellises for EQ and DEC --- p.37
Chapter 5 --- Performance Analysis --- p.40
Chapter 5.1 --- Simulation Model and Settings --- p.40
Chapter 5.2 --- Performance Expectations --- p.43
Chapter 5.3 --- Simulation Results and Discussions --- p.49
Chapter 6 --- Concluding Remarks --- p.55
Bibliography --- p.56
"Novel turbo-equalization techniques for coded digital transmission". Université catholique de Louvain, 2004. http://edoc.bib.ucl.ac.be:81/ETD-db/collection/available/BelnUcetd-12042004-160602/.
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