【摘要】：為了減少信道中噪聲對信號的干擾,提高通信系統(tǒng)的可靠性,信道編碼是一個(gè)重要的技術(shù)手段。尤其在日趨復(fù)雜點(diǎn)電磁環(huán)境中,除了常規(guī)的加性高斯白噪聲,突發(fā)噪聲的出現(xiàn)使信道環(huán)境更加惡劣。因此對突發(fā)信道中信道編碼技術(shù)的研究日益成為通信領(lǐng)域的研究熱點(diǎn)之一。本文以突發(fā)信道中的短碼編碼為研究背景,比較不同編碼算法的短碼在突發(fā)信道和AWGN信道間的性能優(yōu)異,研究對象分別是具有很強(qiáng)糾錯(cuò)能力的RS碼和性能接近香農(nóng)限的LDPC碼。通過分析其編譯碼算法原理,對LDPC碼的算法提出改進(jìn)。使其于突發(fā)信道獲得相對較好的性能提升。本文的主要工作包含以下幾個(gè)方面:首先,論文研究了具有很強(qiáng)糾錯(cuò)能力的RS碼編譯碼算法,通過搭建系統(tǒng)仿真平臺(tái),對RS短碼編碼在AWGN信道和突發(fā)信道進(jìn)行系統(tǒng)仿真,分析其抗突發(fā)錯(cuò)誤能力。接著,本文以LDPC碼為研究手段,研究了LDPC線性編碼、BP譯碼和多種LDPC碼的構(gòu)造方法。其中包括:Gallager的LDPC碼構(gòu)造方法、Mackay構(gòu)造方法(Makcay_1A和Mackay_2A)、超輕矩陣構(gòu)造方法(UL_A和UL_B)、PEG大圍長構(gòu)造方法、?旋轉(zhuǎn)LDPC碼的構(gòu)造及其編碼。同時(shí)對于LDPC線性編碼算法中校驗(yàn)矩陣類下三角化的問題,分析了Greedy_A算法解決該問題存在的漏洞,并提出一種新的算法用于類下三角化校驗(yàn)矩陣。新算法彌補(bǔ)了Greedy_A算法存在的不足,且性能和穩(wěn)定程度均優(yōu)于Greedy_A算法。最后,本文介紹了一種抗突發(fā)噪聲的Tanner圖設(shè)計(jì)方法,以此構(gòu)造具有抗突發(fā)噪聲能力的LDPC碼,闡述了構(gòu)造大圍長LDPC碼的PEG算法原理。結(jié)合兩種算法的特點(diǎn),以PEG算法為基礎(chǔ)進(jìn)行改進(jìn),提出了一種兼顧大圍長特性和抗突發(fā)噪聲特性的LDPC碼構(gòu)造方式。并對其進(jìn)行了系統(tǒng)仿真,分析了其作用機(jī)制和理論與仿真結(jié)果出現(xiàn)差距的原因。
[Abstract]:In order to reduce the interference of the noise to the signal and improve the reliability of the communication system, channel coding is an important technical means. Especially in the increasingly complex electromagnetic environment, in addition to the conventional additive Gao Si white noise, the emergence of sudden noise makes the channel environment worse. Therefore, the research of channel coding in burst channel has become one of the hotspots in communication field. In this paper, the short code coding in burst channel is taken as the research background, and the performance of short code with different coding algorithms is compared between burst channel and AWGN channel. The research objects are RS code with strong error-correcting ability and LDPC code with performance close to Shannon limit. By analyzing the principle of encoding and decoding algorithm, the improvement of LDPC code algorithm is put forward. It can improve the performance of burst channel relatively well. The main work of this paper includes the following aspects: firstly, this paper studies the RS codec algorithm with strong error-correcting ability. By building the system simulation platform, the RS short code coding is simulated in the AWGN channel and burst channel. The ability of resisting sudden error is analyzed. Then, the construction methods of LDPC linear coding, BP decoding and various LDPC codes are studied by means of LDPC codes. Including: Gallager's LDPC code construction method, Mackay construction method (Makcay_1A and Mackay_2A), ultra-light matrix construction method (UL_A and UL_B), PEG large girth construction method),? Construction and coding of rotating LDPC codes. At the same time, for the problem of triangulation of check matrix in LDPC linear coding algorithm, this paper analyzes the loophole of Greedy_A algorithm to solve this problem, and proposes a new algorithm for triangulation check matrix under class. The new algorithm makes up for the deficiency of Greedy_A algorithm, and its performance and stability are better than that of Greedy_A algorithm. Finally, this paper introduces a design method of Tanner diagram to resist burst noise, which is used to construct LDPC codes with the ability of resisting burst noise. The principle of PEG algorithm for constructing large girth LDPC codes is expounded. Combined with the characteristics of the two algorithms and improved on the basis of the PEG algorithm, this paper proposes a construction method of LDPC codes which takes into account the characteristics of large girth and anti-burst noise. The mechanism of the system and the reason of the gap between the theory and the simulation result are analyzed.
【學(xué)位授予單位】：電子科技大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2014
【分類號】：TN911.22

【參考文獻(xiàn)】

相關(guān)博士學(xué)位論文 前1條

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本文編號：2426682