An innovative low-density parity-check code design with near-Shannon-limit performance and simple implementation

Eroz, Mustafa; Sun, Feng-Wen; Lee, Lin-Nan

doi:10.1109/tcomm.2005.861681

Cited by 34 publications

(24 citation statements)

References 6 publications

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“…In our context, all the messages can be classified into two categories, according to the MET edge they are circulating about. To obtain a probabilistic distribution for ditTerent types of messages, we normalize (9) and (10) J(Zq ; C q) = 1 -E:~, q = 1,2, '" Q, (12) where E:~::::; E:g .. • ::::; E:~. The term on the left side of (12) denotes the bitwise mutual information for modulation level q, which achieves its maximum when the binary input C q is uniformly distributed, while the right side is the capacity of a BEC channel with era sure probability E:~.…”

Section: Density Evolution Over Surrogate Channelsmentioning

confidence: 99%

“…As demonstrated by [11], the structural simplicity can be admitted into the code ensemble to facilitate a linear complexity for encoding and decoding, without compromising the performance in both waterfall and error floor regions. In particular, for noniterative modulation and conventional sum-product decoding, the DVB-S2 codes have been shown to exhibit a gap of only 0.7-0.8 dB to Shannon capacity limit at a bit error rate of 10-6 [12]. As a consequence, they have been adopted by standardization bodies for second generation terrestrial (DVB-T2) and cable communications (DVB-C2), and will be reused over terrestrial and cable channels.…”

Section: Introductionmentioning

confidence: 99%

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Demultiplexer design for multi-edge type LDPC coded modulation

Lei

Gao

Spasojević

et al. 2009

2009 IEEE International Symposium on Information Theory

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Generally, the capacity-achieving signaling design for a specific channel should consider the joint optimization of channel coding and modulation. Nevertheless, coding theorists and practitioners have recognized that a well-designed LDPC code can achieve capacityapproaching performance universally across a range of data transmission and storage channels. A pronounced example is the forward error correction scheme adopted recently by the second generation standards for digital video broadcasting (DVB), wherein the same LDPC codes are expected to be reused over satellite, terrestrial and cable channels. However, to accommodate the spectral efficiency of different channel type, the coded bits should be mapped to the modulator judiciously. The well-known BICM strategy employs a large random bit interleaver, which typically yields good performance for an arbitrary choice of constellation mapper. However, it is problematic for high-speed coding and modulation due to the large amount of memory and circuits routing required. This motivates us to impose structural simplicity on the bit interleaver configuration so that the coded bits are de-multiplexed systematically into parallel groups to feed the constellation mapper. In this paper, we focus on the design of bit demultiplexers for multi-level modulations by applying the framework of multi-edge type (MET) LDPC. Since the channel-dependence of a given code ensemble is dominated by the mutual information between the input and output of the effective channel, we propose to simplify the analysis of the decoding behavior by using a set of surrogate binary erasure channels (BEC). Simulation results indicate that the proposed bit demultiplexer surpasses the performance of the heuristic interleaving strategy specified in second generation DVB standard for terrestrial channels (DVB-T2).

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Section: Density Evolution Over Surrogate Channelsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Demultiplexer design for multi-edge type LDPC coded modulation

Lei

Gao

Spasojević

et al. 2009

2009 IEEE International Symposium on Information Theory

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“…Designing the matrix of the code is out of the scope of the present letter. We adopt the LDPC code with codeword length 64 800 and rate 5/6, overhead of 20%, proposed in [14], whose matrices are of public domain, thus making our results easy to reproduce. The BER was measured through Monte Carlo simulations in presence of Wiener PN with σ of 6.2 · 10 −2 rad and 8 · 10 −2 rad.…”

Section: Simulation Resultsmentioning

confidence: 99%

Impact of Nonideal Phase Reference on Soft Decoding of Differentially Encoded Modulation

Magarini

Barletta

Spalvieri

et al. 2012

IEEE Photon. Technol. Lett.

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The performance of coded modulation schemes based on the concatenation of a forward-error correction (FEC) code and differentially encoded quadrature amplitude modulations (QAMs) in the presence of Wiener phase noise is considered. Log-likelihood ratios, required to perform soft decoding, are first derived for the case in which the phase of the received carrier is assumed to be perfectly known, and then used to obtain the performance for nonideal reference of phase. Simulation results of the post-FEC bit-error rate are presented for a near-Shannon limit low-density parity check code with an overhead of 20%. The performance loss, compared to ideal coherent demodulation, is evaluated for two different linewidths of the phase noise in case of quadrature-phase shift keying and 16-QAM transmission.

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“…The adoption of LDPC codes enables a performance within 1 dB of the Shannon limit in AWGN [6], whereas the use of 2DRC improves the reception robustness in fading channels. In particular, the reception of strong line-of-sight (LoS) echoes coming from different transmitters in single frequency networks (SFN) might result in the presence of deep notches in the frequency response of the channel.…”

Section: Introductionmentioning

confidence: 99%