Results 1 - 10 of 2,018

LDPC Codes

by On Taylor Series, Mahmoud Ahmadian-attari, Hamid Saeedi , 1103
"... A new approach for the approximation of the channel log-likelihood ratio (LLR) for wireless channels based on Taylor series is proposed. The approximation is applied to the uncorrelated flat Rayleigh fading channel with unknown channel state information at the receiver. It is shown that the proposed ..."
Abstract - Add to MetaCart
that the proposed approximation greatly simplifies the calculation of channel LLRs, and yet provides results almost identical to those based on the exact calculation of channel LLRs. The results are obtained in the context of bit-interleaved coded modulation (BICM) schemes with low-density parity-check (LDPC) codes

Error-floors of LDPC codes

by Tom Richardson - Proceedings of the 41st Annual Conference on Communication, Control and Computing , 2003
"... We introduce a computational technique that accurately predicts performance for a given LDPC code in the error floor region. We present some results obtained by applying the technique and describe certain aspects of it. 1 ..."
Abstract - Cited by 175 (1 self) - Add to MetaCart
We introduce a computational technique that accurately predicts performance for a given LDPC code in the error floor region. We present some results obtained by applying the technique and describe certain aspects of it. 1

Stochastic decoding of LDPC codes

by Saeed Sharifi Tehrani, Student Member, Warren J. Gross, Shie Mannor - IEEE Commun. Lett , 2006
"... Abstract — This letter presents the first successful method for iterative stochastic decoding of state-of-the-art Low-Density Parity-Check (LDPC) codes. The proposed method shows the viability of the stochastic approach for decoding LDPC codes on factor graphs. In addition, simulation results for a ..."
Abstract - Cited by 17 (5 self) - Add to MetaCart
Abstract — This letter presents the first successful method for iterative stochastic decoding of state-of-the-art Low-Density Parity-Check (LDPC) codes. The proposed method shows the viability of the stochastic approach for decoding LDPC codes on factor graphs. In addition, simulation results for a

Combinatorial Constructions of LDPC Codes

by P. S. Guin, J. Lodge
"... Abstract | In this paper we study low density parity check (LDPC) codes where the structure of the equa-tions arises from high girth graphs. We also discuss two modications, recoding and optimization of scale factors, to the standard decoding methods for LDPC codes. 1 ..."
Abstract - Add to MetaCart
Abstract | In this paper we study low density parity check (LDPC) codes where the structure of the equa-tions arises from high girth graphs. We also discuss two modications, recoding and optimization of scale factors, to the standard decoding methods for LDPC codes. 1

Lecture 33: LDPC Codes

by unknown authors , 2007
"... Low Density Parity Check (LDPC) codes were first introduced by Gallager [1] in his thesis. After the invention, these codes were largely forgotten and there was “no activity ” till mid-late 90s when there was a renewed spurt of research activity on LDPC codes. Available resource for the state-of-the ..."
Abstract - Add to MetaCart
Low Density Parity Check (LDPC) codes were first introduced by Gallager [1] in his thesis. After the invention, these codes were largely forgotten and there was “no activity ” till mid-late 90s when there was a renewed spurt of research activity on LDPC codes. Available resource for the state

perfect decoding of LDPC codes

by Xiaofei Huang - in Proceedings of IEEE International Symposium on Information Theory (ISIT), 2005
"... Abstract — Cooperative optimization is a new way for finding global optima of complicated functions of many variables. It has some important properties not possessed by any conventional optimization methods. It has been successfully applied in solving many large scale optimization problems in image ..."
Abstract - Cited by 7 (1 self) - Add to MetaCart
processing, computer vision, and computational chemistry. This paper shows the application of this optimization principle in decoding LDPC codes, which is another hard combinatorial optimization problem. In our experiments, it significantly out-performed the sumproduct algorithm, the best known method

On the Design of Universal LDPC Codes

by Ali Sanaei, Mahdi Ramezani, Masoud Ardakani , 806
"... Abstract—Low-density parity-check (LDPC) coding for a multitude of equal-capacity channels is studied. First, based on numerous observations, a conjecture is stated that when the belief propagation decoder converges on a set of equal-capacity channels, it would also converge on any convex combinatio ..."
Abstract - Add to MetaCart
Abstract—Low-density parity-check (LDPC) coding for a multitude of equal-capacity channels is studied. First, based on numerous observations, a conjecture is stated that when the belief propagation decoder converges on a set of equal-capacity channels, it would also converge on any convex

Applying LDPC Codes to the GPRS

by Fakheredine Keyrouz
"... currently uses the well-known convolutional code as a Forward Error Correction (FEC) mechanism, and the Viterbi algorithm for decoding. With the recent introduction of Multimedia Broadcast Multicast Services (MBMS), new applications that require more bandwidth and reliability are foreseen. It is kno ..."
Abstract - Add to MetaCart
. It is known that the current GPRS system does not perform well enough without further modifications, therefore, more efficient information distribution schemes must be considered. To meet these increased requirements, especially for MBMS, we study the introduction of carefully designed LDPC codes

Asymmetric quantum LDPC codes

by Pradeep Kiran Sarvepalli, Martin Rötteler - In Proc. IEEE ISIT
"... Abstract — Recently, quantum error-correcting codes were proposed that capitalize on the fact that many physical error models lead to a significant asymmetry between the probabilities for bit flip and phase flip errors. An example for a channel which exhibits such asymmetry is the combined amplitude ..."
Abstract - Cited by 13 (1 self) - Add to MetaCart
that combines BCH and finite geometry LDPC codes. I.

Reduced-Complexity Decoding of LDPC Codes

by Jinghu Chen, Ajay Dholakia, Evangelos Eleftheriou, Marc P. C. Fossorier, Xiao-yu Hu , 2005
"... Various log-likelihood-ratio-based belief-propagation (LLR-BP) decoding algorithms and their reduced-complexity derivatives for low-density parity-check (LDPC) codes are presented. Numerically accurate representations of the check-node update computation used in LLR-BP decoding are described. Furthe ..."
Abstract - Cited by 102 (2 self) - Add to MetaCart
Various log-likelihood-ratio-based belief-propagation (LLR-BP) decoding algorithms and their reduced-complexity derivatives for low-density parity-check (LDPC) codes are presented. Numerically accurate representations of the check-node update computation used in LLR-BP decoding are described
Results 1 - 10 of 2,018