Download or read book LDPC Coded Modulations written by Michele Franceschini and published by Springer Science & Business Media. This book was released on 2009-04-09 with total page 201 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book focuses on the analysis and design of low-density parity-check (LDPC) coded modulations, which are becoming part of several current and future communication systems, such as high-throughput terrestrial and satellite wireless networks. In this book, a two-sided perspective on the design of LDPC coded systems is proposed, encompassing both code/modulation optimization (transmitter side) and detection algorithm design (receiver side). After introducing key concepts on error control coding, in particular LDPC coding, and detection techniques, the book presents several relevant applications. More precisely, by using advanced performance evaluation techniques, such as extrinsic information transfer charts, the optimization of coded modulation schemes are considered for (i) memoryless channels, (ii) dispersive and partial response channels, and (iii) concatenated systems including differential encoding. This book is designed to be used by graduate students working in the field of communication theory, with particular emphasis on LDPC coded communication schemes, and industry experts working on related fields.

Download or read book Multi Edge Low Density Parity Check Coded Modulation written by Lei Zhang and published by . This book was released on 2011 with total page 184 pages. Available in PDF, EPUB and Kindle. Book excerpt: A method for designing low-density parity-check (LDPC) codes for bandwidth-efficient high-order coded modulation is proposed. Code structure utilizes the multi-edge-type LDPC code ensemble to achieve an improved match between codeword bit protection capabilities and modulation bit-channel capacities over existing LDPC coded modulation techniques. The multi-dimensional EXIT vector field for the specific multi-edge parameterization is developed for the analysis and design of code ensembles. A multi-dimensional EXIT decoding convergence condition is derived to enable efficient optimization. Code design results in terms of ensemble thresholds and finite-length Monte-Carlo simulations indicate that the new technique improves on the state-of-the-art performance, with sig- nificantly lower design and implementation complexity.

Download or read book Coded Modulation Using LDPC Codes for Memoryless Channels written by Yaniv Nana and published by . This book was released on 2003 with total page 68 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book High Efficiency LDPC Coded Modulation written by Stefan Neuhaus and published by . This book was released on 2014-02-11 with total page 240 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Bit Interleaved Coded Modulation written by Albert Guillén i Fàbregas and published by Now Publishers Inc. This book was released on 2008 with total page 170 pages. Available in PDF, EPUB and Kindle. Book excerpt: Bit-Interleaved Coded Modulation is a comprehensive study of the subject, providing a comprehensive review of one of the most important coding schemes in modern communication systems.

Download or read book An LDPC Coded modulation Scheme for Discrete Memoryless Channels written by Josef Rotenshtein and published by . This book was released on 2009 with total page 104 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Dialogues polonais fran ais et allemands written by and published by . This book was released on 1816 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Universal Serially Concatenated Trellis Coded Modulations and Rate compatible High rate LDPC Codes written by Wen-Yen Weng and published by . This book was released on 2007 with total page 216 pages. Available in PDF, EPUB and Kindle. Book excerpt: For the space-time channel, by de-multiplexing the symbols across the antennas, universal SCTCMs for the period-2 PFC deliver consistent performance over the eigenvalue skew of the matrix channel. Within the family of channels having the same eigenvalue skew, a time-varying linear transformation (TVLT) is used to mitigate the performance variation over different eigenvectors. Because of their consistent performance over all channels, the proposed codes will have good frame-error-rate (FER) performance over any quasi-static fading distribution.

Download or read book Coding for Wireless Channels written by Ezio Biglieri and published by Springer Science & Business Media. This book was released on 2006-07-06 with total page 433 pages. Available in PDF, EPUB and Kindle. Book excerpt: Accessible introduction to the theoretical foundations of modern coding theory Including numerous applications to wireless transmission systems The author is famous in the field of coding and wireless communications for his work in the area of faded channels & communcations.

Download or read book Bandwidth efficient Communication Systems Based on Finite length Low Density Parity Check Codes written by and published by . This book was released on 2006 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Low density parity check (LDPC) codes are linear block codes constructed by pseudo-random parity check matrices. These codes are powerful in terms of error performance and, especially, have low decoding complexity. While infinite-length LDPC codes approach the capacity of communication channels, finite-length LDPC codes also perform well, and simultaneously meet the delay requirement of many communication applications such as voice and backbone transmissions. Therefore, finite-length LDPC codes are attractive to employ in low-latency communication systems. This thesis mainly focuses on the bandwidth-efficient communication systems using finite-length LDPC codes. Such bandwidth-efficient systems are realized by mapping a group of LDPC coded bits to a symbol of a high-order signal constellation. Depending on the systems' infrastructure and knowledge of the channel state information (CSI), the signal constellations in different coded modulation systems can be two-dimensional multilevel/multiphase constellations or multi-dimensional space-time constellations. In the first part of the thesis, two basic bandwidth-efficient coded modulation systems, namely LDPC coded modulation and multilevel LDPC coded modulation, are investigated for both additive white Gaussian noise (AWGN) and frequency-flat Rayleigh fading channels. The bounds on the bit error rate (BER) performance are derived for these systems based on the maximum likelihood (ML) criterion. The derivation of these bounds relies on the union bounding and combinatoric techniques. In particular, for the LDPC coded modulation, the ML bound is computed from the Hamming distance spectrum of the LDPC code and the Euclidian distance profile of the two-dimensional constellation. For the multilevel LDPC coded modulation, the bound of each decoding stage is obtained for a generalized multilevel coded modulation, where more than one coded bit is considered for level. For both systems, the bounds are confirmed by the simulation.

Download or read book LDPC coded Modulation for Transmission Over AWGN and Flat Rayleigh Fading Channels written by Rui Yang and published by . This book was released on 2010 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: La modulation codée est une technique de transmission efficace en largeur de bande qui intègre le codage de canal et la modulation en une seule entité et ce, afin d'améliorer les performances tout en conservant la même efficacité spectrale comparé à la modulation non codée. Les codes de parité à faible densité (low-density parity-check codes, LDPC) sont les codes correcteurs d'erreurs les plus puissants et approchent la limite de Shannon, tout en ayant une complexité de décodage relativement faible. L'idée de combiner les codes LDPC et la modulation efficace en largeur de bande a donc été considérée par de nombreux chercheurs. Dans ce mémoire, nous étudions une méthode de modulation codée à la fois puissante et efficace en largeur de bande, ayant d'excellentes performances de taux d'erreur binaire et une complexité d'implantation faible. Ceci est réalisé en utilisant un encodeur rapide, un décoder de faible complexité et aucun entrelaceur. Les performances du système proposé pour des transmissions sur un canal additif gaussien blanc et un canal à évanouissements plats de Rayleigh sont évaluées au moyen de simulations. Les résultats numériques montrent que la méthode de modulation codée utilisant la modulation d'amplitude en quadrature à M niveaux (M-QAM) peut atteindre d'excellentes performances pour toute une gamme d'efficacité spectrale. Une autre contribution de ce mémoire est une méthode simple pour réaliser une modulation codée adaptative avec les codes LDPC pour la transmission sur des canaux à évanouissements plats et lents de Rayleigh. Dans cette méthode, six combinaisons de paires encodeur modulateur sont employées pour une adaptation trame par trame. L'efficacité spectrale moyenne varie entre 0.5 et 5 bits/s/Hz lors de la transmission. Les résultats de simulation montrent que la modulation codée adaptative avec les codes LDPC offre une meilleure efficacité spectrale tout en maintenant une performance d'erreur acceptable.

Download or read book Low complexity Forward Error Correction and Modulation for Optical Communication written by Masoud Barakatain and published by . This book was released on 2021 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: A novel low-complexity architecture for forward error correction (FEC) in optical communication is proposed. The architecture consists of an inner soft-decision low-density parity check (LDPC) code concatenated with an outer hard-decision staircase or zipper code. The inner code is tasked with reducing the bit error probability below the level that allows the outer code to deliver on the stringent output bit error rate required in optical communication. A hardware-friendly quasi-cyclic construction is adopted for the inner codes. The concatenated code is optimized by minimizing the estimated data-flow at the decoder. A method is developed to obtain complexity-optimized inner-code ensembles. A key feature emerging from this optimization is that it pays to leave some inner codeword bits completely uncoded, thereby greatly reducing the decoding complexity. The trade-off between performance and complexity of the designed codes is characterized by a Pareto frontier. In binary modulation, up to 71% reduction in complexity is achieved compared to previously existing designs. Higher-order modulation via multilevel coding (MLC) is compared with bit-interleaved coded modulation (BICM) from a performance-versus-complexity standpoint. In both approaches, complexity-optimized error-reducing LDPC inner codes are designed for concatenation with an outer hard-decision code, for various modulation orders. Code designs for MLC are shown to provide significant advantages relative to designs for BICM over the entire performance-complexity tradeoff space, for a range of modulation orders. Codes designed for MLC can operate with 78% less complexity, or provide up to 1.2 dB coding gain compared to designs for BICM. A multi-rate and channel-adaptive inner-code architecture is also proposed. A tool is developed to optimize low-complexity rate- and channel-configurable concatenated FEC schemes via an MLC architecture. Compared to previously existing FEC schemes, up to 63% reduction in decoding complexity, or up to 0.6 dB coding gain is obtained. Code designs for MLC in combination with four-dimensional signal constellations are also considered. The design method is generalized to obtain complexity-optimized non-binary LDPC codes to concatenate with outer zipper codes. Gains of up to 1 dB over the conventional schemes are reported. The possibility of using a novel class of nonlinear codes in FEC design is also investigated.

Download or read book Design and Analysis of Multilevel Coded Modulation for Multi node Networks written by Ahmed Attia Abotabl and published by . This book was released on 2017 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: During the last several decades, information theory has made significant advances in the analysis of the limits of communication in multi-node networks and the methods that can approach those limits. This dissertation studies new multi-level architectures for coded modulation in multi-node networks that aim to approach, in the practical realm, the capacity limits unveiled by information theory. For the two-user additive white Gaussian noise (AWGN) broadcast channel, a multi-level coding architecture is proposed whose performance can approach the entire capacity region, and whose attractive features include a convenient partition of the two users’ data so that one and only one of the modulation bit levels (and the corresponding encoder) must contend with both users’ data. Practical aspects of the problem, including allocation of levels to users and finding level-wise code rates, have been addressed. For the full-duplex decode-forward relay channel, a pragmatic yet capacity-approaching construction is proposed that synthesizes the components of full-duplex transmission via distinct signal levels of a multi-level code at the source and at the relay. The rate penalty due to linearity of component codes is analyzed and to avoid it, a solution is proposed involving the labeling of signal constellations. Simulations show that the proposed architecture together with good point-to-point codes can achieve excellent performance. For the full-duplex decode-compress-forward relay channel, a multi-level coding architecture is proposed and analyzed that achieves rates very close to the best known (information theoretic) achievable rates. The performance of the proposed architecture is evaluated using a combination of low-density parity-check (LDPC) codes and polar codes. For the design of coded modulation for the discrete-input, Gaussian noise wiretap channels, a rate splitting method is proposed to allow a convenient construction of wiretap channel codes via a combination of two separate encoders operating on the data and the dither components. This technique leads naturally to the construction of multilevel codes for the AWGN wiretap channel where the message and the dither are encoded through separate levels without compromising secrecy. The effect of maximum likelihood decoding and multistage decoding at the legitimate receiver, as well as the effect of modulation labeling, are studied.

Download or read book Optical Fiber Telecommunications VIB written by Ivan B. Djordjevic and published by Elsevier Inc. Chapters. This book was released on 2013-05-11 with total page 91 pages. Available in PDF, EPUB and Kindle. Book excerpt: This chapter represents an overview of advanced coding techniques for optical communication. Topics include: codes on graphs, coded modulation, rate-adaptive coded modulation, and turbo equalization. The main objectives of this chapter are: (i) to describe different classes of codes on graphs of interest for optical communications, (ii) to describe how to combine multilevel modulation and channel coding, (iii) to describe how to perform equalization and soft-decoding jointly, and (iv) to demonstrate efficiency of joint de-modulation, decoding, and equalization in dealing with various channel impairments simultaneously. Codes on graphs of interest for next-generation FEC for high-speed optical transport include turbo codes, turbo-product codes and low-density parity-check (LDPC) codes. We describe both binary and nonbinary LDPC codes, their design and decoding algorithms. We also discuss an FPGA implementation of decoders for binary LDPC codes. We demonstrate that an LDPC-coded turbo equalizer is an excellent candidate to simultaneously mitigate uncompensated chromatic dispersion, PMD, fiber nonlinearities and I/Q-imbalance. For completeness of presentation, we also provide the information capacity study of optical channels with memory.

Download or read book Nonbinary LDPC Coded Modulation Schemes for High Speed Optical Communication Networks written by Murat Arabaci and published by . This book was released on 2010 with total page 246 pages. Available in PDF, EPUB and Kindle. Book excerpt: IEEE has recently finished its ratification of the IEEE Standard 802.3ba in June 2010 which set the target Ethernet speed as 100 Gbps. The studies on the future trends of the ever-increasing demands for higher speed optical fiber communications show that there is no sign of decline in the demand. Constantly increasing internet traffic and the bandwidth-hungry multimedia services like HDTV, YouTube, voice-over-IP, etc. can be shown as the main driving forces. Indeed, the discussions over the future upgrades on the Ethernet speeds have already been initiated. It is predicted that the next upgrade will enable 400 Gbps Ethernet and the one after will be toward enabling the astounding 1 Tbps Ethernet. Although such high and ultra high transmission speeds are unprecedented over any transmission medium, the bottlenecks for achieving them over the optical fiber remains to be fundamental. At such high operating symbol rates, the signal impairments due to inter- and intra-channel fiber nonlinearities and polarization mode dispersion get exacerbated to the levels that cripple the high-fidelity communication over optical fibers. Therefore, efforts should be exerted to provide solutions that not only answer the need for high-speed transmission but also maintain low operating symbol rates. In this dissertation, we contribute to these efforts by proposing nonbinary-LDPC-coded modulation (NB-LDPC-CM) schemes as enabling technologies that can meet both the aforementioned goals. We show that our proposed NB-LDPC-CM schemes can outperform their prior-art, binary counterparts called bit-interleaved coded modulation (BI-LDPC-CM) schemes while attaining the same aggregate bit rates at a lower complexity and latency. We provide comprehensive analysis on the computational complexity of both schemes to justify our claims with solid evidence. We also compare the performances of both schemes by using amplified spontaneous emission (ASE) noise dominated optical fiber transmission and short to medium haul optical fiber transmission scenarios. Both applications show outstanding performances of NB-LDPC-CM schemes over the prior-art BI-LDPC-CM schemes with increasing gaps in coding gain as the transmission speeds increase. Furthermore, we present how a rate-adaptive NB-LDPC-CM can be employed to fully utilize the resources of a long haul optical transport network throughout its service time.

Download or read book Contemporary Coding Techniques and Applications for Mobile Communications written by Onur Osman and published by CRC Press. This book was released on 2009-05-07 with total page 362 pages. Available in PDF, EPUB and Kindle. Book excerpt: Modern error control coding methods based on turbo coding have essentially solved the problem of reliable data communications over noisy channels. Contemporary Coding Techniques and Applications for Mobile Communications provides a clear, comprehensive, and practical grounding on the subject matter, examining the fundamentals, theory, and ap

Download or read book Channel Coding Techniques for Wireless Communications written by K. Deergha Rao and published by Springer Nature. This book was released on 2019-11-22 with total page 484 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book discusses the latest channel coding techniques, MIMO systems, and 5G channel coding evolution. It provides a comprehensive overview of channel coding, covering modern techniques such as turbo codes, low-density parity-check (LDPC) codes, space–time coding, polar codes, LT codes, and Raptor codes as well as the traditional codes such as cyclic codes, BCH, RS codes, and convolutional codes. It also explores MIMO communications, which is an effective method for high-speed or high-reliability wireless communications. It also examines the evolution of 5G channel coding techniques. Each of the 13 chapters features numerous illustrative examples for easy understanding of the coding techniques, and MATLAB-based programs are integrated in the text to enhance readers’ grasp of the underlying theories. Further, PC-based MATLAB m-files for illustrative examples are included for students and researchers involved in advanced and current concepts of coding theory.