本文關(guān)鍵詞：Turbo碼與RS-Turbo級聯(lián)編碼在光正交頻分復(fù)用系統(tǒng)中的應(yīng)用　出處：《天津理工大學(xué)》2016年碩士論文　論文類型：學(xué)位論文

  更多相關(guān)文章： 光正交頻分復(fù)用 Turbo碼 RS-Turbo級聯(lián)編碼 Turbo譯碼算法

【摘要】：光正交頻分復(fù)用技術(shù)(OOFDM)做為長距離、高速率、大容量光通信傳輸系統(tǒng)的一種關(guān)鍵技術(shù)成為了研究的熱點。但是由于光纖非線性,信號的高峰均功率比(PAPR)以及光放大器的自發(fā)輻射噪聲(ASE)等的存在,對系統(tǒng)的誤碼率性能產(chǎn)生了嚴重的影響。因此,本文通過理論分析和仿真對OOFDM系統(tǒng)進行了研究并提高系統(tǒng)的誤碼率(BER)性能。本文的主要內(nèi)容如下:1.介紹OFDM、OOFDM以及編碼等技術(shù)的發(fā)展情況和研究現(xiàn)狀。2.介紹本文需要用到的基本原理。如OFDM原理、Turbo碼和RS碼的編解碼原理。3.建立了一個采用Turbo編碼的直接檢測光正交頻分復(fù)用系統(tǒng),比較分析了編碼系統(tǒng)與未編碼系統(tǒng)的傳輸性能。在編碼系統(tǒng)中采用了三種解碼算法,分別為:Log-MAP,Max-Log-MAP和Threshold Max-Log-MAP。通過比較三種解碼算法,發(fā)現(xiàn)使用Max-Log-MAP算法時,系統(tǒng)的誤碼率性能最好。在傳輸距離為240km時,傳輸速率為30Gb/s的未編碼系統(tǒng)的誤碼率達到10-3數(shù)量級時,光信噪比要達到24dB,而傳輸速率為50Gb/s的Turbo編碼系統(tǒng),達到同樣誤碼率性能時,光信噪比只需達到20dB。4.將RS-Turbo級聯(lián)編碼應(yīng)用到相干光正交頻分復(fù)用系統(tǒng)中。對于RS-Turbo級聯(lián)碼,采用了碼率為1/2的Turbo碼和RS(186,166,8)。Turbo碼的解碼算法采用了兩種,分別是Max-Log-MAP算法和Log-MAP算法,RS碼解碼采用了迭代BM算法。仿真結(jié)果顯示,采用RS-Turbo級聯(lián)編碼的CO-OFDM系統(tǒng)的誤碼率性能在高光信噪比時有明顯改善,與采用Turbo編碼的系統(tǒng)相比,迭代次數(shù)明顯減少。另外,當Turbo碼采用Max-Log-MAP算法解碼時,采用RS-Turbo級聯(lián)編碼的CO-OFDM系統(tǒng)可以無差錯傳輸400km,而采用Turbo編碼的系統(tǒng)在誤碼率低于10-4數(shù)量級時只能傳輸240km。5.搭建了基于相干光正交頻分復(fù)用和PDM(Polarization Division Multiplexing)的WDM(Wavalength Division Multiplexing)系統(tǒng),并將Turbo碼和RS-Turbo級聯(lián)編碼應(yīng)用到系統(tǒng)中,仿真證明在光信噪比為22dB時,可以實現(xiàn)200Gb/s數(shù)據(jù)的無誤碼傳輸。
[Abstract]:Optical orthogonal frequency division multiplexing (OOFDM) technology for long distance, high rate, a key technology of large capacity optical communication system has become a hot research. But because the optical nonlinearity, signal peak to average power ratio (PAPR) and optical amplifier spontaneous emission noise (ASE) such as the existence of the a serious impact on the BER performance of the system. Therefore, this paper through theoretical analysis and Simulation of OOFDM system are researched and improved the system bit error rate (BER) performance. The main contents of this paper are as follows: 1. introduction of OFDM,.2. and the current situation of the development of OOFDM and encoding technology this paper introduces the basic principle to use such as OFDM. The principle of coding and decoding principle of.3. Turbo code and RS code is established using a Turbo encoding a direct detection optical orthogonal frequency division multiplexing system, a comparative analysis of the transmission performance of encoding system and encoding system. Not in the series The code system adopts three decoding algorithms, respectively: Log-MAP, Max-Log-MAP and Threshold Max-Log-MAP. by comparing the three kinds of decoding algorithm, using Max-Log-MAP algorithm, the BER performance of the system. In the best transmission distance is 240km, the transmission rate of 30Gb/s encoding system without bit error rate of 10-3 magnitude, reach the 24dB ratio of optical signal to noise, and the transmission rate of Turbo encoding 50Gb/s system, achieve the same BER performance, the optical signal-to-noise ratio only reaches 20dB.4. the RS-Turbo cascade encoding applied to coherent optical orthogonal frequency division multiplexing system. For the RS-Turbo concatenated code, the 1/2 code rate Turbo code and RS (186166,8) decoding algorithm of.Turbo codes with two, respectively Max-Log-MAP and Log-MAP algorithm, RS decoding using the iterative BM algorithm. The simulation results show that the CO-OFDM system with RS-Turbo cascade encoding error Rate performance at high optical SNR is improved obviously, compared with the system using Turbo encoding, the number of iterations was significantly reduced. In addition, when the Turbo code decoding using Max-Log-MAP algorithm, using CO-OFDM encoding system RS-Turbo cascade can be error free transmission of 400km, and the Turbo encoding system at a bit error rate of 10-4 level only transmission of 240km.5. to build a coherent optical orthogonal frequency division multiplexing and PDM (Polarization Division Multiplexing) based on WDM (Wavalength Division Multiplexing) system, and the Turbo code and RS-Turbo concatenated encoding is applied to the system, simulation results show that in the optical signal-to-noise ratio is 22dB, can achieve 200Gb/s data transmission without error.

【學(xué)位授予單位】：天津理工大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2016
【分類號】：TN911.22

【相似文獻】

相關(guān)碩士學(xué)位論文 前1條

1 胡桂彬;Turbo碼與RS-Turbo級聯(lián)編碼在光正交頻分復(fù)用系統(tǒng)中的應(yīng)用[D];天津理工大學(xué);2016年

，

本文編號：1405557