Low-density Parity-check Codes with Erasures and Puncturing - read free eBook in online reader or directly download on the web page. Select files or add your book in reader. Download and read online ebook Low-density Parity-check Codes with Erasures and Puncturing write by Jeongseok Ha Ha. This book was released on 2003. Low-density Parity-check Codes with Erasures and Puncturing available in PDF, EPUB and Kindle. In this thesis, we extend applications of Low-Density Parity-Check (LDPC) codes to a combination of constituent sub-channels, which is a mixture of Gaussian channels with erasures. This model, for example, represents a common channel in magnetic recordings where thermal asperities in the system are detected and represented at the decoder as erasures. Although this channel is practically useful, we cannot find any previous work that evaluates performance of LDPC codes over this channel. We are also interested in practical issues such as designing robust LDPC codes for the mixture channel and predicting performance variations due to erasure patterns (random and burst), and finite block lengths. On time varying channels, a common error control strategy is to adapt the coding rate according to available channel state information (CSI). An effective way to realize this coding strategy is to use a single code and puncture it in a rate-compatible fashion, a so-called rate-compatible punctured code (RCPC). We are interested in the existence of good puncturing patterns for rate-changes that minimize performance loss. We show the existence of good puncturing patterns with analysis and verify the results with simulations. Universality of a channel code across a broad range of coding rates is a theoretically interesting topic. We are interested in the possibility of using the puncturing technique proposed in this thesis for designing universal LDPC codes. We also consider how to design high rate LDPC codes by puncturing low rate LDPC codes. The new design method can take advantage of longer effect block lengths, sparser parity-check matrices, and larger minimum distances of low rate LDPC codes.
Design of Rate-compatible Structured Low-density Parity-check Codes
Design of Rate-compatible Structured Low-density Parity-check Codes - read free eBook in online reader or directly download on the web page. Select files or add your book in reader. Download and read online ebook Design of Rate-compatible Structured Low-density Parity-check Codes write by Jaehong Kim. This book was released on 2006. Design of Rate-compatible Structured Low-density Parity-check Codes available in PDF, EPUB and Kindle. The main objective of our research is to design practical low-density parity-check (LDPC) codes which provide a wide range of code rates in a rate-compatible fashion. To this end, we first propose a rate-compatible puncturing algorithm for LDPC codes at short block lengths (up to several thousand symbols). The proposed algorithm is based on the claim that a punctured LDPC code with a smaller level of recoverability has better performance. The proposed algorithm is verified by comparing performance of intentionally punctured LDPC codes (using the proposed algorithm) with randomly punctured LDPC codes. The intentionally punctured LDPC codes show better bit error rate (BER) performances at practically short block lengths. Even though the proposed puncturing algorithm shows excellent performance, several problems are still remained for our research objective. First, how to design an LDPC code of which structure is well suited for the puncturing algorithm. Second, how to provide a wide range of rates since there is a puncturing limitation with the proposed puncturing algorithm. To attack these problems, we propose a new class of LDPC codes, called efficiently-encodable rate-compatible (E2RC) codes, in which the proposed puncturing algorithm concept is imbedded. The E2RC codes have several strong points. First, the codes can be efficiently encoded. We present low-complexity encoder implementation with shift-register circuits. In addition, we show that a simple erasure decoder can also be used for the linear-time encoding of these codes. Thus, we can share a message-passing decoder for both encoding and decoding in transceiver systems that require an encoder/decoder pair. Second, we show that the non-systematic parts of the parity-check matrix are cycle-free, which ensures good code characteristics. Finally, the E2RC codes having a systematic rate-compatible puncturing structure show better puncturing performance than any other LDPC codes in all ranges of code rates.
Topics in Low Density Parity Check Codes for the Binary Erasure Channel
Topics in Low Density Parity Check Codes for the Binary Erasure Channel - read free eBook in online reader or directly download on the web page. Select files or add your book in reader. Download and read online ebook Topics in Low Density Parity Check Codes for the Binary Erasure Channel write by Ohad Barak. This book was released on 2002. Topics in Low Density Parity Check Codes for the Binary Erasure Channel available in PDF, EPUB and Kindle.
Puncturing, Mapping, and Design of Low-density Parity-check Codes
Puncturing, Mapping, and Design of Low-density Parity-check Codes - read free eBook in online reader or directly download on the web page. Select files or add your book in reader. Download and read online ebook Puncturing, Mapping, and Design of Low-density Parity-check Codes write by Gerd Richter. This book was released on 2009. Puncturing, Mapping, and Design of Low-density Parity-check Codes available in PDF, EPUB and Kindle.
LDPC Code Designs, Constructions, and Unification
LDPC Code Designs, Constructions, and Unification - read free eBook in online reader or directly download on the web page. Select files or add your book in reader. Download and read online ebook LDPC Code Designs, Constructions, and Unification write by Juane Li. This book was released on 2017. LDPC Code Designs, Constructions, and Unification available in PDF, EPUB and Kindle. In this book, leading authorities unify algebraic- and graph-based LDPC code designs and constructions into a single theoretical framework.
