Multi-Edge Low-Density Parity-Check Coded Modulation

Multi-Edge Low-Density Parity-Check Coded Modulation PDF Author: Lei Zhang
Publisher:
ISBN: 9780494766071
Category :
Languages : en
Pages : 184

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Book Description
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.

Multi-Edge Low-Density Parity-Check Coded Modulation

Multi-Edge Low-Density Parity-Check Coded Modulation PDF Author: Lei Zhang
Publisher:
ISBN: 9780494766071
Category :
Languages : en
Pages : 184

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Book Description
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.

Coded Modulation with Low Density Parity Check Codes

Coded Modulation with Low Density Parity Check Codes PDF Author: Ravi Narayanaswami
Publisher:
ISBN:
Category :
Languages : en
Pages : 162

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Book Description


LDPC Coded Modulations

LDPC Coded Modulations PDF Author: Michele Franceschini
Publisher: Springer Science & Business Media
ISBN: 3540694579
Category : Technology & Engineering
Languages : en
Pages : 201

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Book Description
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.

Bandwidth Efficient Coded Modulation Using Low Density Parity Check Codes

Bandwidth Efficient Coded Modulation Using Low Density Parity Check Codes PDF Author: Deepak Sridhara
Publisher:
ISBN:
Category :
Languages : en
Pages : 364

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Bandwidth-efficient Communication Systems Based on Finite-length Low Density Parity Check Codes

Bandwidth-efficient Communication Systems Based on Finite-length Low Density Parity Check Codes PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages :

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Book Description
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.

Coding for Wireless Channels

Coding for Wireless Channels PDF Author: Ezio Biglieri
Publisher: Springer Science & Business Media
ISBN: 1402080840
Category : Technology & Engineering
Languages : en
Pages : 433

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Book Description
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.

Reliability-based Coded Modulation for Low-density Parity-check Codes [microform]

Reliability-based Coded Modulation for Low-density Parity-check Codes [microform] PDF Author: Robert D. Maddock
Publisher: Library and Archives Canada = Bibliothèque et Archives Canada
ISBN: 9780612974241
Category : Coding theory
Languages : en
Pages : 170

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Book Description


Low-Complexity Decoding of Low-Density Parity Check Codes Through Optimal Quantization and Machine Learning and Optimal Modulation and Coding for Short Block-Length Transmissions

Low-Complexity Decoding of Low-Density Parity Check Codes Through Optimal Quantization and Machine Learning and Optimal Modulation and Coding for Short Block-Length Transmissions PDF Author: Linfang Wang
Publisher:
ISBN:
Category :
Languages : en
Pages : 0

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Book Description
This dissertation investigates two topics in channel coding theory: low-complexity decoder design for low-density parity-check (LDPC) codes and reliable communication in the short blocklength regime. For the first topic, we propose a finite-precision decoding method that features the three steps of Reconstruction, Computation, and Quantization (RCQ). The parameters of the RCQ decoder, for both the flooding-scheduled and the layered-scheduled, can be designed efficiently using discrete density evolution featuring hierarchical dynamic quantization (HDQ). To further reduce the hardware usage of the RCQ decoder, we propose a second RCQ framework called weighted RCQ (W-RCQ). Unlike the RCQ decoder, whose quantization and reconstruction parameters change in each layer and iteration, the W-RCQ decoder limits the number of quantization and reconstruction functions to a very small number during the decoding process, for example, three or four. However, the W-RCQ decoder weights check-to-variable node messages using dynamic parameters optimized by a quantized neural network. The proposed W-RCQ decoder uses fewer parameters than the RCQ decoder, thus requiring much fewer resources such as lookup tables. For the second topic, we apply probabilistic amplitude shaping (PAS) to cyclic redundancy check (CRC)-aided tail-biting trellis-coded modulation (TCM). CRC-TCM-PAS produces practical codes for short block lengths on the additive white Gaussian noise (AWGN) channel. In the transmitter, equally likely message bits are encoded by a distribution matcher (DM), generating amplitude symbols with a desired distribution.A CRC is appended to the sequence of amplitude symbols, and this sequence is then encoded and modulated by TCM to produce real-valued channel input signals. We prove that the sign values produced by the TCM are asymptotically equally likely to be positive or negative. The CRC-TCM-PAS scheme can thus generate channel input symbols with a symmetric capacity-approaching probability mass function. We also provide an analytical upper bound on the frame error rate of the CRC-TCM-PAS system over the AWGN channel. This FER upper bound is the objective function for jointly optimizing the CRC and convolutional code. This paper also proposes a multi-composition DM, a collection of multiple constant-composition DMs. The optimized CRC-TCM-PAS systems achieve frame error rates below the random coding union (RCU) bound in AWGN and outperform the short-blocklength PAS systems with various other forward error correction codes.

Dialogues polonais, français et allemands

Dialogues polonais, français et allemands PDF Author:
Publisher:
ISBN:
Category : French language
Languages : en
Pages :

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Optical Fiber Telecommunications VIB

Optical Fiber Telecommunications VIB PDF Author: Ivan B. Djordjevic
Publisher: Elsevier Inc. Chapters
ISBN: 0128060786
Category : Technology & Engineering
Languages : en
Pages : 91

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Book Description
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.