Due to the growing popularity of Internet of People (IoP) and its impacts on human activity, it has quickly become an important research field and hot subject. Since one purpose of IoP is to connect people to people, ...
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Due to the growing popularity of Internet of People (IoP) and its impacts on human activity, it has quickly become an important research field and hot subject. Since one purpose of IoP is to connect people to people, personal live video delivery that has been popular recently can also be regarded as an important application of IoP. For improving the video quality of video communication services, Raptor code has been adopted in various broadband communication systems. In this paper, we propose a systematic Raptor code decoder based on the group parameters for a group of encoding symbols. For a Raptor code application that can frequently use one or several fixed source block lengths (i.e., the number of source symbols in a source block), we could produce the corresponding group parameters in advance and use them to decode the received encoding symbols more efficiently. For personal live video delivery scenario based on the IPTV delivery, the simulation results show that our decoder is faster than the conventional Raptor code decoder which is adopted by the DVB and 3GPP specifications.
Dynamic or adaptive Huffman coding, proposed by Gallager [1] and extended by Knuth [2], can be used for compressing a continuous stream. Our proposal for accomplishing the same task is termed here as block Huffman cod...
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Dynamic or adaptive Huffman coding, proposed by Gallager [1] and extended by Knuth [2], can be used for compressing a continuous stream. Our proposal for accomplishing the same task is termed here as block Huffman coding. This is an easy and simple solution to compress continuous data by applying simple Huffman coding in blocks of data. For each block, a different header is stored. This header is shipped with each block of compressed data. However, to keep the header overhead low, we have used the proposed storage efficient header [3]. (C) 2003 Elsevier Ltd, All rights reserved.
An [] code is a binary linear code of block length , dimension and minimum Hamming distance . Since the minimum distance determines the error detection or correction capability, it is desired that is as large as possi...
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An [] code is a binary linear code of block length , dimension and minimum Hamming distance . Since the minimum distance determines the error detection or correction capability, it is desired that is as large as possible for the given block length and dimension . One of the most fundamental problems in coding theory is to construct codes with best possible minimum distances. This problem is very difficult in both theory and practice. During the last decades, it has proved that the class of quasi-cyclic (QC) codes contain many such codes. In this paper, augmentation of binary QC codes is studied. A new augmentation algorithm is presented, and 10 new -generator QC codes that are better than previously known code have been constructed. Furthermore, Construction X has been applied to obtain another 18 new improved binary linear codes. With the standard construction techniques, a total of 124 new binary linear codes that improve the lower bound on the minimum distance have been obtained.
The distance distribution of a code is the vector whose ith entry is the number of pairs of codewords with distance i. We investigate the structure of the distance distribution for cyclic orbit codes, which are subspa...
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The distance distribution of a code is the vector whose ith entry is the number of pairs of codewords with distance i. We investigate the structure of the distance distribution for cyclic orbit codes, which are subspace codes generated by the action of F-qn* on an F-q-subspace U of F-qn. Note that F-qn* is a Singer cycle in the general linear group of all F-q-automorphisms of F-qn. We show that for full-length orbit codes with maximal possible distance the distance distribution depends only on q,n, and the dimension of U. For full-length orbit codes with lower minimum distance, we provide partial results towards a characterization of the distance distribution, especially in the case that any two codewords intersect in a space of dimension at most 2. Finally, we briefly address the distance distribution of a union of full-length orbit codes with maximum distance.
This note presents some new information on how the minimum distance of the generalized toric code corresponding to a fixed set of integer lattice points S subset of R-2 varies with the base field. The main results sho...
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This note presents some new information on how the minimum distance of the generalized toric code corresponding to a fixed set of integer lattice points S subset of R-2 varies with the base field. The main results show that in some cases, over sufficiently large fields, the minimum distance of the code corresponding to a set S will be the same as that of the code corresponding to the convex hull conv(S). In an example, we will also discuss a [49,12,28] generalized toric code over F-8, better than any previously known code according to M. Grassl's online tables, as of December 2012. (C) 2013 Elsevier Inc. All rights reserved.
We apply automata theory and Karp's minimum mean weight cycle algorithm to minimum density problems in coding theory. Using this method, we find the new upper bound 53/126 approximate to 0:4206 for the minimum den...
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We apply automata theory and Karp's minimum mean weight cycle algorithm to minimum density problems in coding theory. Using this method, we find the new upper bound 53/126 approximate to 0:4206 for the minimum density of an identifying code on the infinite hexagonal grid, down from the previous record of 3/7 approximate to 0:4286
We consider the problem of source compression under three different scenarios in the one-shot (nonasymptotic) regime. To be specific, we prove one-shot achievability and converse bounds on the coding rates for distrib...
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We consider the problem of source compression under three different scenarios in the one-shot (nonasymptotic) regime. To be specific, we prove one-shot achievability and converse bounds on the coding rates for distributed source coding, source coding with coded side information available at the decoder, and source coding under maximum distortion criterion. The one-shot bounds obtained are in terms of smooth max R,nyi entropy and smooth max R,nyi divergence. Our results are powerful enough to yield the results that are known for these problems in the asymptotic regime both in the i.i.d. (independent and identically distributed) and non-i.i.d. settings.
In this paper we propose memory protection architectures based on nonlinear single-error-correcting, double-error-detecting (SEC-DED) codes. Linear SEC-DED codes widely used for design of reliable memories cannot dete...
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In this paper we propose memory protection architectures based on nonlinear single-error-correcting, double-error-detecting (SEC-DED) codes. Linear SEC-DED codes widely used for design of reliable memories cannot detect and can miscorrect lots of errors with large Hamming weights. This may be a serious disadvantage for many modern technologies when error distributions are hard to estimate and multi-bit errors are highly probable. The proposed protection architectures have fewer undetectable errors and fewer errors that are miscorrected by all codewords than architectures based on linear codes with the same dimension at the cost of a small increase in the latency penalty, the area overhead and the power consumption. The nonlinear SEC-DED codes are generalized from the existing perfect nonlinear codes (Vasil'ev codes, Probl Kibern 8:375-378, 1962;Phelps codes, SIAM J Algebr Discrete Methods 4:398-403, 1983;and the codes based on one switching constructions, Etzion and Vardy, IEEE Trans Inf theory 40:754-763, 1994). We present the error correcting algorithms, investigate and compare the error detection and correction capabilities of the proposed nonlinear SEC-DED codes to linear extended Hamming codes and show that replacing linear extended Hamming codes by the proposed nonlinear SEC-DED codes results in a drastic improvement in the reliability of the memory systems in the case of repeating errors or high multi-bit error rate. The proposed approach can be applied to RAM, ROM, FLASH and disk memories.
FPT3 was the last of the five in-pile integral experiments in the Phebus FP programme, whose overall purpose was to investigate fuel rod degradation and behaviour of fission products (FPs) released via the primary coo...
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FPT3 was the last of the five in-pile integral experiments in the Phebus FP programme, whose overall purpose was to investigate fuel rod degradation and behaviour of fission products (FPs) released via the primary coolant circuit into the containment building. The results contribute to validation of models and computer codes used to calculate the source term for a severe accident with core meltdown in light water reactors. Unlike the previous tests, FPT3 used B4C as absorber material in the pre-irradiated (24.5 GWd/tU) fuel bundle, while featuring a steam-poor period as in FPT2, which used Ag/In/Cd absorber. The main FPT3 containment results are summarised: the source term of FPs, fuel and structural materials from the experimental circuit into the containment;the composition, morphology and deposition processes of aerosols in the containment atmosphere;the specific behaviour of the radiologically significant FP iodine;and finally the performance of passive autocatalytic recombiner (PAR) coupons exposed to the containment atmosphere just after the transient. The major elements contributing to the aerosol mass in the containment are the volatile FPs Cs and Mo, the control rod material B, the cladding material Sn, and the instrumentation materials Re and W (specific to Phebus tests). The fractional compositions, leaving aside the control rod materials, were very similar in FPT2 and FPT3. After reactor shutdown, homogenisation of the aerosol size in the containment led to only one aerosol population, similar to the previous tests. Long-term aerosol deposition in the containment was dominated by gravitational settling and diffusiophoresis, but significant deposits were also measured on the vertical wall, consisting of multi-component aerosols, again comparable with FPT2. A significant result of FPT3 was that iodine is mainly in gaseous form in the atmosphere up to containment isolation;the rest in aerosol form. Another important result was the fast decrease of the iodin
The non-linear filtering is a commonly used time-domain technique for narrowband interference (NBI) suppression in the direct-sequence spread spectrum (DSSS) communication systems. In this study, the authors analyse h...
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The non-linear filtering is a commonly used time-domain technique for narrowband interference (NBI) suppression in the direct-sequence spread spectrum (DSSS) communication systems. In this study, the authors analyse how the decision feedback error of the spread spectrum (SS) signal influences the performance of the NBI prediction. A partial-code-aided scheme is proposed, which despreads partial chips in a spreading sequence and reconstructs the rest part by spreading the bit decision. This method utilises partial spreading gain to improve the decision accuracy of the SS signals while keeping similar time consumption and implementation complexity with the traditional scheme. It has been verified by simulation that with different NBI models and under different channel conditions, the proposed non-linear filtering method always outperforms the traditional one with chip-wise decision feedback.
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