Improved Design of Unequal Error Protection LDPC Codes

Sandberg, Sara

doi:10.1155/2010/423989

Cited by 4 publications

(2 citation statements)

References 13 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Some results of this paper have been prepublished at conferences [10,17,41] or will appear in [36]. UEP LDPC codes for higher-order modulation, which were not presented in here, have recently been published in [42]; for results on UEP multilevel codes, the reader is referred to [22].…”

Section: Acknowledgmentsmentioning

confidence: 99%

UEP Concepts in Modulation and Coding

Henkel

Hassan

Deetzen³

et al. 2010

Advances in Multimedia

Self Cite

View full text Add to dashboard Cite

First unequal error protection (UEP) proposals date back to the 1960's (Masnick and Wolf; 1967), but now with the introduction of scalable video, UEP develops to a key concept for the transport of multimedia data. The paper presents an overview of some new approaches realizing UEP properties in physical transport, especially multicarrier modulation, or with LDPC and Turbo codes. For multicarrier modulation, UEP bit-loading together with hierarchical modulation is described allowing for an arbitrary number of classes, arbitrary SNR margins between the classes, and arbitrary number of bits per class. In Turbo coding, pruning, as a counterpart of puncturing is presented for flexible bit-rate adaptations, including tables with optimized pruning patterns. Bit- and/or check-irregular LDPC codes may be designed to provide UEP to its code bits. However, irregular degree distributions alone do not ensure UEP, and other necessary properties of the parity-check matrix for providing UEP are also pointed out. Pruning is also the means for constructing variable-rate LDPC codes for UEP, especially controlling the check-node profile.

show abstract

Section: Acknowledgmentsmentioning

confidence: 99%

UEP Concepts in Modulation and Coding

Henkel

Hassan

Deetzen³

et al. 2010

Advances in Multimedia

Self Cite

View full text Add to dashboard Cite

show abstract

“…For example, one might give more importance to certain data symbols and use BPSK (M = 2) for these, but QPSK (M = 4) for other less important symbols. This is related to what is called unequal error protection in the literature [11,12]. To keep our ideas and notation focused we don't consider this further here.…”

Section: Introductionmentioning

confidence: 99%

Carrier Phase and Amplitude Estimation for Phase Shift Keying Using Pilots and Data

McKilliam

Pollok

Cowley

et al. 2014

IEEE Trans. Signal Process.

View full text Add to dashboard Cite

Abstract-We consider least squares estimators of carrier phase and amplitude from a noisy communications signal that contains both pilot signals, known to the receiver, and data signals, unknown to the receiver. We focus on signaling constellations that have symbols evenly distributed on the complex unit circle, i.e., M -ary phase shift keying. We show, under reasonably mild conditions on the distribution of the noise, that the least squares estimator of carrier phase is strongly consistent and asymptotically normally distributed. However, the amplitude estimator is not consistent, but converges to a positive real number that is a function of the true carrier amplitude, the noise distribution and the size of the constellation. Our theoretical results can also be applied to the case where no pilot symbols exist, i.e., noncoherent detection. The results of Monte Carlo simulations are provided and these agree with the theoretical results.

show abstract

Non-volatile memory reduction based on 1-D memory space mapping of a specific set of QC-LDPC codes

Young

Chia

Yang

et al. 2012

J Wireless Com Network

View full text Add to dashboard Cite

Supporting a great diversity of multi-rate H-matrices for multiple communication protocols requires a large amount of non-volatile memory, which may consume a large silicon area or logic elements and constrain the implementation of an overall decoder. Therefore, schemes for memory reduction are necessary to make the paritycheck storage more compact. This study proposes a specific set of quasi-cyclic low-density parity-check (LDPC) (QC-LDPC) codes which can transfer a traditional two-dimensional (2-D) parity-check matrix (H-matrix) into a onedimensional (1-D) memory space. Compared to the existing schemes, the proposed codes and memory reduction scheme do achieve significant reduction rates. Within a fixed memory space, many more H-matrices for diverse communication protocols can be saved via the proposed QC-LDPC codes, which are well constructed from modified Welch-Costas sequences. Furthermore, relatively good error performances, which outperform computergenerated random LDPC codes and Sridhara-Fuja-Tanner codes, are also shown in our simulation results. Consequently, we conclude that the proposed QC-LDPC codes can enlarge the capacity for saving much more low-BER (bit error rate) H-matrices within a fixed memory space.

show abstract

Improved Design of Unequal Error Protection LDPC Codes

Cited by 4 publications

References 13 publications

UEP Concepts in Modulation and Coding

UEP Concepts in Modulation and Coding

Carrier Phase and Amplitude Estimation for Phase Shift Keying Using Pilots and Data

Non-volatile memory reduction based on 1-D memory space mapping of a specific set of QC-LDPC codes

Contact Info

Product

Resources

About