Results 261 to 270 of about 128,644 (293)

Design of an LDPC code with low error floor

Proceedings. International Symposium on Information Theory, 2005. ISIT 2005., 2005
A search algorithm for stopping sets in a Tanner graph is proposed for designing good low-density parity-check (LDPC) codes. By applying the belief-propagation algorithm with messages containing the information of originated variable nodes and their connected edges, the stopping sets can be detected.
Sang Hyun Lee, Kwang Soon Kim, Jae Kyun Kwon, Yun Hee Kim, Jae Young Ahn   +4 more
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Error floors of non-binary LDPC codes

2010 IEEE International Symposium on Information Theory, 2010
In this paper, we analyze (2, k)-regular non-binary low-density parity-check codes over the binary erasure channels. We propose a method to improve the error floors by optimizing labels in zigzag cycles in the Tanner graph. We analyze the error floors for codes designed by the proposed optimization method and show that the error floors are decreasing ...
Takayuki Nozaki, Kenta Kasai, Koichi Sakaniwa   +2 more
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In-service testing OFDM error floor by constellation analysis

2017 25th International Conference on Software, Telecommunications and Computer Networks (SoftCOM), 2017
Residual BER – error floor is the ultimate metrics for the end-to-end transmission performance, but in practice can be assessed only by out-of-service tests, which network operators in particular try to avoid best they can, preferring in-service practical test methods. In this regard, constellation analysis is an excellent tool to not only identify and
Adriana Lipovac, Sibila Isak-Zatega, Pamela Njemcevic   +2 more
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BER and Error-Floor Calculation for Multi-Access PCTH

Global Telecommunications Conference, 2002. GLOBECOM '02. IEEE, 2002
Pseudo-chaotic time hopping (PCTH) is a recently proposed modulation scheme for UWB impulse radio. PCTH exploits concepts from symbolic dynamics to generate aperiodic spreading sequences. In this paper, we present a general analytical expression for the average BER (bit-error-rate) of a synchronous multi-access PCTH system, as a function of the cross ...
Gian Mario Maggio, David Laney, Lawrence Larson   +2 more
openaire   +1 more source

Error Floors of LDPC Codes on the Binary Symmetric Channel

2006 IEEE International Conference on Communications, 2006
In this paper, we propose a semi-analytical method to compute error floors of LDPC codes on the binary symmetric channel decoded iteratively using the Gallager B algorithm. The error events of the decoder are characterized using combinatorial objects called trapping sets, originally defined by Richardson. In general, trapping sets are characteristic of
Shashi Kiran Chilappagari, Sundararajan Sankaranarayanan, Bane Vasic   +2 more
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Error floor analysis

2009
Introduction In the previous chapter we analyzed the performance of iterative codes by calculating their threshold and thus comparing their performance in high-noise channels with the channel's capacity. In that analysis we considered the iterative decoding of code ensembles with given component codes, averaging over all possible interleaver–edge ...
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Lowering Error Floors Using Dithered Belief Propagation

2010 IEEE Global Telecommunications Conference GLOBECOM 2010, 2010
We propose dithered belief propagation decoding algorithms to reduce the number of decoding failures of a belief propagation decoder and lower the error floor. The random nature of the algorithms enables a low hardware complexity compared to previously reported techniques. We introduce two dithering methods that target check node operations and channel
François Leduc-Primeau, Saied Hemati, Shie Mannor, Warren J. Gross   +3 more
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Iterative Source–Channel Decoding With Reduced Error Floors

IEEE Journal of Selected Topics in Signal Processing, 2011
Audio-visual source encoders for digital mobile communications extract parameters that-due to delay and complexity constraints-exhibit some residual redundancy. This residual redundancy can be exploited by iterative source-channel decoding (ISCD) to improve the robustness against transmission noise by performing soft parameter detection as part of the ...
Laurent Schmalen, Peter Vary
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Causes and dynamics of LDPC error floors on AWGN channels

2011 49th Annual Allerton Conference on Communication, Control, and Computing (Allerton), 2011
It is well-known that the performance of low-density parity-check codes is compromised by the emergence of an error floor, which is caused by so-called trapping sets. By identifying the dominant trapping sets, this error floor can be estimated analytically using a linear model.
Shuai Zhang, Christian Schlegel
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Construction of irregular LDPC codes with low error floors

IEEE International Conference on Communications, 2003. ICC '03., 2004
This work explains the relationship between cycles, stopping sets, and dependent columns of the parity check matrix of low-density parity-check (LDPC) codes. Furthermore, it discusses how these structures limit LDPC code performance under belief propagation decoding.
Tao Tian, Christopher R. Jones 0001, John D. Villasenor, Richard D. Wesel   +3 more
openaire   +1 more source