共查询到18条相似文献,搜索用时 156 毫秒
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针对范德蒙阵列纠删码算法,介绍了纠删码编译码过程,重点论述了范德蒙码编码算法和译码算法,提出了适合在嵌入式系统实现时的快速算法;在Matlab软件中构建了数字卫星广播系统(DVB-S)模型并进行了信道误码分布仿真,获得了DVB-S系统的误码分布,分析了在系统中使用范德蒙纠删码的可行性;提出了纠删码与系统中的纠错码级联使用模型,并对算法的纠错性能进行仿真,仿真结果表明级联模型能大大提高无线传输系统的可靠性。 相似文献
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光通信系统级联码的仿真研究 总被引:1,自引:1,他引:0
随着光通信技术向更长距离、更大容量和更高速度的进一步发展,有必要深入研究性能更好的FEC码型方案。在光通信应用的众多FEC码型中,级联码具有短码的复杂度和长码的性能,具有极强的纠突发和纠随机错误的能力,是光通信系统中高效编码的主要研究对象。文中主要对RS-BCH型级联码进行了理论分析及建模仿真,与一般循环码相比该级联码纠错性能优良、冗余度适中、易于实现,更适用于高速光通信系统。 相似文献
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关于纠删码的研究与进展 总被引:2,自引:1,他引:2
该文简述了几类纠删码的纠删原理,系统地综合分析了各类纠删码的优缺点及其相互区别与联系,证明了若选取MDS(Maximal Distance Separable)码作为纠删码,只要接收者接收到源数据个数的数据,就能恢复原来的源数据。分析结果表明:复损码以及旋风(Tornado)码不仅能以线性时间可编码和可成功地译码,而且能以任意接近删除信道容量的速率进行传输,最后指出了目前复损码的研究中需要解决的一些问题,这些分析和结论为进一步研究纠删码提供了理论基础和新的思路。 相似文献
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Kaiyan Zhu Hongyu Wang Fanglin Niu Fengjiao Jiang 《International Journal of Wireless Information Networks》2014,21(4):317-324
In order to reduce computation complexity and latency in cooperative communication system based on fountain code, a decomposed LT codes (DLT) based cooperative transmission scheme was proposed. The scheme comprises of two layers of random encoding but only a single layer of decoding. A general decomposition technique for the decomposed LT codes construction is developed. The transmission latency for the proposed scheme was analyzed. Simulation results show that the total time consumed under the proposed scheme can be significantly reduced compared to direct transmission and conventional cooperative transmission based on LT codes in the medium to high packet erasure rate regimes. Moreover, With the increase of packet erasure rate, the advantage of the proposed scheme is more evident. 相似文献
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In this paper, we investigate and compare the asymptotic performance of concatenated convolutional coding schemes over GF(4) over additive white Gaussian noise (AWGN) channels. Both parallel concatenated codes (PCC) and serial concatenated codes (SCC) are considered. We construct such codes using optimal non‐binary convolutional codes where optimality is in the sense of achieving the largest minimum distance for a fixed number of encoder states. Code rates of the form k0/(k0 + 1) for k0=1, 8, and 64 are considered, which suite a wide spectrum of communications applications. For all of these code rates, we find the minimum distance and the corresponding multiplicity for both concatenated code systems. This is accomplished by feeding the encoder with all possible weight‐two and weight‐three input information patterns and monitoring, at the output of the encoder, the weight of the corresponding codewords and their multiplicity. Our analytical results indicate that the SCC codes considerably outperform their counterpart PCC codes at a much lower complexity. Inspired by the superiority of SCC codes, we also discuss a mathematical approach for analysing such codes, leading to a more comprehensive analysis and allowing for further improvement in performance by giving insights on designing a proper interleaver that is capable of eliminating the dominant error patterns. Copyright © 2004 John Wiley & Sons, Ltd. 相似文献
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对一种码率为1/2的部分系统turbo码性能进行了讨论。它是通过对码率为1/3的turbo码的校验位和信息位进行删余得到的。这种码的“误码下限”(error-floor)比对应的系统码要低。因此,码率为1/2的turbo码,在没有增加编码和译码复杂性的情况下,通过简单地对信息位和校验位的删除可以提高性能。 相似文献
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A new high rate code scheme is proposed in this paper. It consists of serial concatenated recursive systematic ordinary (nonpunctured) convolutional codes with only 8 states in the trellis of the corresponding reciprocal dual codes. With a low complexity and highly parallel decoding algorithm, over additive white Gaussian noise channels, the proposed codes can achieve good bit error rate (BER) performance comparable to that of turbo codes and low density parity check (LDPC) codes. At code rate R=16/17, the overall decoding complexity of the proposed code scheme is almost half that of the LDPC codes. 相似文献
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An embedded source code allows the decoder to reconstruct the source progressively from the prefixes of a single bit stream. It is desirable to design joint source-channel coding schemes which retain the capability of progressive reconstruction in the presence of channel noise or packet loss. Here, we address the problem of joint source-channel coding of images for progressive transmission over memoryless bit error or packet erasure channels. We develop a framework for encoding based on embedded source codes and embedded error correcting and error detecting channel codes. For a target transmission rate, we provide solutions and an algorithm for the design of optimal unequal error/erasure protection. Three performance measures are considered: the average distortion, the average peak signal-to-noise ratio, and the average useful source coding rate. Under the assumption of rate compatibility of the underlying channel codes, we provide necessary conditions for progressive transmission of joint source-channel codes. We also show that the unequal error/erasure protection policies that maximize the average useful source coding rate allow progressive transmission with optimal unequal protection at a number of intermediate rates 相似文献
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纠错编码技术通过引入冗余增加可靠性,是现代通信的关键技术之一。无速率编码是一类新兴纠错编码,其速率可以根据信道状态自适应改变,编译码算法较为简单,且性能优异,可以适用于不同的应用场景,因此受到了国内外学者和工业界的关注。介绍了4种经典或新兴的无速率编码方案,包括卢比变换(Luby Transform,LT)码、Raptor码、在线喷泉码(OFC)和BATS(Batched Sparse)码。介绍无速率编码的基本原理,通过其发展过程比较不同无速率编码的特点。阐述了这些无速率编码的编译码方法,并简要介绍其最新的研究进展。最后,介绍无速率编码在广播通信及不等差保护、无线传感器网络、车联网、存储以及分布式计算等新老场景中的应用。无速率编码是一种复杂度低、灵活度高的编码,随着新型无速率编码的发展,在未来的分布式系统等场景中将会有更广泛的应用。 相似文献
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Khaled H. Biyari Saud A. Al-Semari 《International Journal of Satellite Communications and Networking》1995,13(2):137-145
It is known that concatenated coding can significantly enhance the performance of digital communication systems operating over fading channels when compared to uncoded or single-coded systems. The price to be paid for such an improvement, however, is a substantial increase in the required bandwidth. In this paper, we consider the use of a concatenation scheme in which the inner code is a trellis-coded modulation (TCM) system. The analysis is carried out for two different outer codes: a binary Golay code and a non-binary Reed-Solomon code. Results obtained for the Rayleigh and Rician fading channels through analytical bounds indicate that the use of this system does provide a significant reduction in the bit error probability, a fact that is also verified through computer simulation. Unlike a traditional concatenated system, the proposed method achieves the coding gain while maintaining acceptable bandwidth efficiency. 相似文献