This study is concerned with the application of non-binary low-densityparity-check (NB-LDPC) codes to binary input inter-symbol interference channels. Two low-complexity joint detection/decoding algorithms are propos...
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This study is concerned with the application of non-binary low-densityparity-check (NB-LDPC) codes to binary input inter-symbol interference channels. Two low-complexity joint detection/decoding algorithms are proposed. One is referred to as max-log-MAP/X-EMS algorithm, which is implemented by exchanging soft messages between the max-log-MAP detector and the extended min-sum (EMS) decoder. The max-log-MAP/X-EMS algorithm is applicable to general NB-LDPC codes. The other one, referred to as Viterbi/GMLGD algorithm, is designed in particular for majority-logic decodable NB-LDPC codes. The Viterbi/GMLGD algorithm works in an iterative manner by exchanging hard-decisions between the Viterbi detector and the generalised majority-logic decoder (GMLGD). As a by-product, a variant of the original EMS algorithm is proposed, which is referred to as mu-EMS algorithm. In the mu-EMS algorithm, the messages are truncated according to an adaptive threshold, resulting in a more efficient algorithm. Simulations results show that the max-log-MAP/X-EMS algorithm performs as well as the traditional iterative detection/decoding algorithm based on the BCJR algorithm and theQ-ary sum-product algorithm, but with lower complexity. The complexity can be further reduced for majority-logic decodable NB-LDPC codes by executing the Viterbi/GMLGD algorithm with a performance degradation within one dB. These algorithms provide good candidates for trade-offs between performance and complexity.
We propose nonbinary LDPC codes concatenated with multiplicative repetition codes. By multiplicatively repeating the (2,3)-regular nonbinary LDPCmother code of rate 1/3, we construct rate-compatible codes of lower rat...
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We propose nonbinary LDPC codes concatenated with multiplicative repetition codes. By multiplicatively repeating the (2,3)-regular nonbinary LDPCmother code of rate 1/3, we construct rate-compatible codes of lower rates. 1/6, 1/9, 1/12,.... Surprisingly, such simple low-rate nonbinary LDPC codes outperform the best low-rate binary LDPC codes so far. Moreover, we propose the decoding algorithm for the proposed codes, which can be decoded with almost the same computational complexity as that of the mother code.
Two-dimensional magnetic recording (TDMR) by shingled magnetic recording (SMR) is one of the most promising technologies for realizing high areal densities. The read/write (R/W) channel model based on a discrete Voron...
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Two-dimensional magnetic recording (TDMR) by shingled magnetic recording (SMR) is one of the most promising technologies for realizing high areal densities. The read/write (R/W) channel model based on a discrete Voronoi model is relatively easily implemented to evaluate the performance of signal processing for TDMR. The nonbinarylow-densityparity-check (LDPC) coding and iterative decoding system provides the better performance compared with the conventional binary LDPC coding system. Furthermore, a two-dimensional equalizer (2D-EQ) can mitigate the influence of the intertrack interference (ITI) in TDMR. In this paper, the symbol-by-symbol turbo equalizer which consists of a symbol-by-symbol a posteriori probability (APP) decoder for a generalized partial response class-I (GPR1) channelwith a 2D-EQ and a sum-product (SP) decoder for a nonbinary LDPC coder overGalois field GF (2(8)) of is evaluated by computer simulation at an areal recording density of 4.12 Tbit/in(2). The result shows that the symbol-by-symbol turbo equalizing system provides an SNR improvement of about 3.7 dB over the bit-by-bit turbo equalizing system.
We show in this paper the achievable improvement of the coding gain in the reverse link (air-to-ground) for the L-band Digital Aeronautical Communications System if the current forward error correction scheme based on...
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ISBN:
(纸本)9781479989409
We show in this paper the achievable improvement of the coding gain in the reverse link (air-to-ground) for the L-band Digital Aeronautical Communications System if the current forward error correction scheme based on a concatenated Reed-olomon convolutional code is replaced by either a turbo code or a nonbinary low-density parity-check code for the smallest assignable data block. Additionally to improving the coding gain, the proposed coding schemes enable a fully iterative detection because of their soft-value decoding algorithms. This improves in general the detection process as a whole.
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