Transactions papers evaluation and design of irregular LDPC codes using ACE spectrum

Vukobratović, Dejan; Šenk, V.

doi:10.1109/tcomm.2009.08.070548

Cited by 26 publications

(43 citation statements)

References 15 publications

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“…One category of such literature, focusses on modification of iterative decoding algorithms, see, e.g., [9], while another category is concerned with the code construction. In the second category, some researchers use indirect measures such as girth [18] or approximate cycle extrinsic message degree (ACE) [19], while others work with direct measures of error floor performance such as the distribution of stopping sets or trapping sets [20], [10], [11]. In [20], edge swapping is proposed as a technique to increase the stopping distance of an LDPC code, and thus to improve its error floor performance over the BEC.…”

Section: Introductionmentioning

confidence: 99%

Lowering the Error Floor of LDPC Codes Using Cyclic Liftings

Asvadi

Banihashemi

Ahmadian-Attari

2011

IEEE Trans. Inform. Theory

105

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Cyclic liftings are proposed to lower the error floor of low-density parity-check (LDPC) codes. The liftings are designed to eliminate dominant trapping sets of the base code by removing the short cycles which form the trapping sets. We derive a necessary and sufficient condition for the cyclic permutations assigned to the edges of a cycle c of length ℓ(c) in the base graph such that the inverse image of c in the lifted graph consists of only cycles of length strictly larger than ℓ(c). The proposed method is universal in the sense that it can be applied to any LDPC code over any channel and for any iterative decoding algorithm. It also preserves important properties of the base code such as degree distributions, encoder and decoder structure, and in some cases, the code rate. The proposed method is applied to both structured and random codes over the binary symmetric channel (BSC). The error floor improves consistently by increasing the lifting degree, and the results show significant improvements in the error floor compared to the base code, a random code of the same degree distribution and block length, and a random lifting of the same degree. Similar improvements are also observed when the codes designed for the BSC are applied to the additive white Gaussian noise (AWGN) channel.

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Section: Introductionmentioning

confidence: 99%

Lowering the Error Floor of LDPC Codes Using Cyclic Liftings

Asvadi

Banihashemi

Ahmadian-Attari

2011

IEEE Trans. Inform. Theory

105

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“…Given an LDPC code with a Tanner graph G, the ACE spectrum of depth d max of G [10] is defined as a d maxtuple η(G) Δ = (η 2 , . .…”

Section: Ace Spectrum and Ace Constrained Code Designmentioning

confidence: 99%

“…Irregular degree distributions which are optimized to render superior waterfall performance will often result in a high error floor in randomly constructed codes. To improve the error floor performance of irregular codes, new constructions are introduced, see, e.g., [8], [11], [3], [4], [9], [10], [1]. Our work is closely related to the constructions introduced in [8], [11], [9], and [10], on one hand, and those in [4], and [1], on the other hand.…”

Section: Introductionmentioning

confidence: 99%

“…ACE constrained LDPC codes were also designed in [8] which outperformed random codes in the error floor region. The ACE metric for a cycle was recently generalized to the ACE spectrum of a Tanner graph in [10], where the authors also devised generalized ACE constrained LDPC codes, further improving the error floor of the codes. Finally, in [9], PEG construction and generalized ACE constrained design were combined for even superior error floor performance.…”

Section: Introductionmentioning

confidence: 99%

“…Compared to the constructions of [8], [9], and [10], which do not have any particular structure, the proposed construction is quasi-cyclic and thus more implementation friendly. Moreover, the approach to achieve a target ACE spectrum is different.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Design of irregular quasi-cyclic protograph codes with low error floors

Asvadi

Banihashemi

Ahmadian-Attari

2011

2011 IEEE International Symposium on Information Theory Proceedings

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We propose a technique to design finite-length irregular low-density parity-check (LDPC) codes over the binaryinput additive white Gaussian noise (AWGN) channel with good performance in both the waterfall and the error floor region. The design process starts from a protograph which embodies a desirable degree distribution. This protograph is then lifted cyclically to a certain block length of interest. The lift is designed carefully to satisfy a certain approximate cycle extrinsic message degree (ACE) spectrum. The target ACE spectrum is one with extremal properties, implying a good error floor performance for the designed code. The proposed construction results in quasicyclic codes which are attractive in practice due to simple encoder and decoder implementation. Simulation results are provided to demonstrate the effectiveness of the proposed construction in comparison with similar existing constructions.

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Low-Density Parity-Check Code Constructions

Flanagan

2014

Academic Press Library in Mobile and Wireless Communications

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Transactions papers evaluation and design of irregular LDPC codes using ACE spectrum

Cited by 26 publications

References 15 publications

Lowering the Error Floor of LDPC Codes Using Cyclic Liftings

Lowering the Error Floor of LDPC Codes Using Cyclic Liftings

Design of irregular quasi-cyclic protograph codes with low error floors

Low-Density Parity-Check Code Constructions

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