New Identification and Decoding Techniques for Low-Density Parity-Check Codes
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| Title: | New Identification and Decoding Techniques for Low-Density Parity-Check Codes |
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| Authors: | Xia, Tian |
| Source: | LSU Doctoral Dissertations |
| Publisher Information: | LSU Scholarly Repository |
| Publication Year: | 2015 |
| Collection: | LSU Digital Commons (Louisiana State University) |
| Subject Terms: | low-density parity-check (LDPC) codes, blind identification, iterative decoding, stopping criterion, scheduling, LDPC convolutional codes, iterative decoding thresholds, Electrical and Computer Engineering |
| Description: | Error-correction coding schemes are indispensable for high-capacity high data-rate communication systems nowadays. Among various channel coding schemes, low-density parity-check (LDPC) codes introduced by pioneer Robert G. Gallager are prominent due to the capacity-approaching and superior error-correcting properties. There is no hard constraint on the code rate of LDPC codes. Consequently, it is ideal to incorporate LDPC codes with various code rate and codeword length in the adaptive modulation and coding (AMC) systems which change the encoder and the modulator adaptively to improve the system throughput. In conventional AMC systems, a dedicated control channel is assigned to coordinate the encoder/decoder changes. A questions then rises: if the AMC system still works when such a control channel is absent. This work gives positive answer to this question by investigating various scenarios consisting of different modulation schemes, such as quadrature-amplitude modulation (QAM), frequency-shift keying (FSK), and different channels, such as additive white Gaussian noise (AWGN) channels and fading channels. On the other hand, LDPC decoding is usually carried out by iterative belief-propagation (BP) algorithms. As LDPC codes become prevalent in advanced communication and storage systems, low-complexity LDPC decoding algorithms are favored in practical applications. In the conventional BP decoding algorithm, the stopping criterion is to check if all the parities are satisfied. This single rule may not be able to identify the undecodable blocks, as a result, the decoding time and power consumption are wasted for executing unnecessary iterations. In this work, we propose a new stopping criterion to identify the undecodable blocks in the early stage of the iterative decoding process. Furthermore, in the conventional BP decoding algorithm, the variable (check) nodes are updated in parallel. It is known that the number of iterations can be reduced by the serial scheduling algorithm. The informed dynamic scheduling (IDS) ... |
| Document Type: | text |
| File Description: | application/pdf |
| Language: | unknown |
| Relation: | https://repository.lsu.edu/gradschool_dissertations/1557; https://repository.lsu.edu/context/gradschool_dissertations/article/2556/viewcontent/uc.pdf |
| DOI: | 10.31390/gradschool_dissertations.1557 |
| Availability: | https://repository.lsu.edu/gradschool_dissertations/1557 https://doi.org/10.31390/gradschool_dissertations.1557 https://repository.lsu.edu/context/gradschool_dissertations/article/2556/viewcontent/uc.pdf |
| Accession Number: | edsbas.246DB9F5 |
| Database: | BASE |
Nájsť tento článok vo Web of Science | Abstract: | Error-correction coding schemes are indispensable for high-capacity high data-rate communication systems nowadays. Among various channel coding schemes, low-density parity-check (LDPC) codes introduced by pioneer Robert G. Gallager are prominent due to the capacity-approaching and superior error-correcting properties. There is no hard constraint on the code rate of LDPC codes. Consequently, it is ideal to incorporate LDPC codes with various code rate and codeword length in the adaptive modulation and coding (AMC) systems which change the encoder and the modulator adaptively to improve the system throughput. In conventional AMC systems, a dedicated control channel is assigned to coordinate the encoder/decoder changes. A questions then rises: if the AMC system still works when such a control channel is absent. This work gives positive answer to this question by investigating various scenarios consisting of different modulation schemes, such as quadrature-amplitude modulation (QAM), frequency-shift keying (FSK), and different channels, such as additive white Gaussian noise (AWGN) channels and fading channels. On the other hand, LDPC decoding is usually carried out by iterative belief-propagation (BP) algorithms. As LDPC codes become prevalent in advanced communication and storage systems, low-complexity LDPC decoding algorithms are favored in practical applications. In the conventional BP decoding algorithm, the stopping criterion is to check if all the parities are satisfied. This single rule may not be able to identify the undecodable blocks, as a result, the decoding time and power consumption are wasted for executing unnecessary iterations. In this work, we propose a new stopping criterion to identify the undecodable blocks in the early stage of the iterative decoding process. Furthermore, in the conventional BP decoding algorithm, the variable (check) nodes are updated in parallel. It is known that the number of iterations can be reduced by the serial scheduling algorithm. The informed dynamic scheduling (IDS) ... |
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| DOI: | 10.31390/gradschool_dissertations.1557 |