DP-16QAM相干光通信系统关键技术的研究

发布时间：2018-01-20 17:45

本文关键词： 光纤通信相干检测 DP-16QAM 数字信号处理光纤非线性载波相位噪声估计与补偿　出处：《北京交通大学》2014年博士论文　论文类型：学位论文

【摘要】：基于高阶调制码型、相干检测和数字信号处理技术的相干光通信,由于其能够实现高频谱效率、在电域实现传输损伤补偿等优势,成为下一代高速光通信系统发展方向。本论文结合国家863项目“160Gb/s一泵多纤光传输技术的研究”以及加拿大自然科学基金战略基金项目‘'Digital signal processing for fiber optic communication",围绕基于偏振复用16进制正交幅度调制(DP-16QAM)码型、相干检测和数字信号处理技术的相干光通信系统进行了深入的理论和实验研究。取得的主要研究成果如下： 1.提出一种改进型四电平信号生成方案,实验生成了高质量14Gbaud/s、28Gbaud/s、32Gbaud/s、40Gbaud/s四电平信号。实验研究了基于改进型四电平信号生成方案的DP-16QAM发射机性能,实验结果显示112Gb/s和224Gb/sDP-16QAM发射机性能与理论值分别仅有2.7dB和3.5dB的光信噪比(OSNR)代价。搭建了112Gb/s DP-16QAM实验传输系统,实验研究了其传输性能。实验结果显示,在仅补偿光纤色散情况下单通道112Gb/s DP-16QAM传输系统最优入纤功率点为-3.5dBm；当前向纠错编码(FEC)阈值为3.8×10-时,实验实现了112Gb/sDP-16QAM信号1470km传输。 2.开发了一套完整的适用于DP-16QAM的相干接收机数字信号处理算法,其中包括基于Gram-Schmidt正交法则的IQ非正交补偿算法；基于频域均衡器的色散补偿算法；数字时钟恢复；偏振复用信号的偏振解复用及动态均衡；载波频偏估计与补偿；载波相位噪声估计与补偿；判决及误码计算。仿真及实验验证了整套数字信号处理算法的性能。首次实验研究了基于Gram-Schmidt正交法则的IQ非正交补偿算法在DP-16QAM系统中的性能。 3.研究了基于数字反向传输(DBP:Digital Back-Propagation)的光纤非线性补偿技术在DP-16QAM长距离相干光通信系统中的应用。分析了偏振复用传输系统中的光纤非线性效应。仿真与实验研究了该补偿技术中加权系数及补偿步长两个关键参数,结果显示：对于特定的传输系统,DBP的加权系数对补偿步长、入纤功率、传输距离等均不敏感。在综合考虑补偿性能及计算复杂度情况下,DBP的最优补偿步长为传输系统的中继距离。采用该补偿技术,112Gb/s DP-16QAM长传输系统的最优入纤功率被提升了2dB；当FEC阈值为3.8x10-时,实验实现了112Gb/s DP-16QAM信号2400km传输,最远传输距离比未采用该技术情况下提升近63%。 4.提出三种基于改进型四相移键控分区算法(MP)的级联载波相位噪声估计(CPE)算法。研究了算法线宽容忍度、相位噪声估计性能、线性及非线性传输性能和硬件复杂度。仿真与实验结果表明：三种算法性能均与相位盲搜索(BPS)算法相近,硬件复杂度却比BPS算法分别降低了1.5-10倍。 5.为了进一步降低硬件复杂度,提出一种基于准零乘法器算法的级联CPE算法。仿真与实验研究结果显示：级联CPE算法的线宽容忍度、相位噪声估计性能、线性及非线性传输性能均与BPS算法相当,但该算法硬件复杂度比BPS算法降低了17倍,是迄今为止报道的针对16QAM调制码型的硬件复杂度最低的前反馈级联CPE算法。 6.提出将线性插值算法应用于载波相位噪声补偿技术中,提出基于线性相位插值(LPI)的增强型载波相位噪声补偿算法,理论与实验研究了该补偿算法性能。仿真与实验结果表明：LPI算法与滑动窗口(SW)补偿算法性能相当,好于数据块平均(BA)补偿算法；然而LPI算法的硬件复杂度仅与BA算法相近,远远低于SW补偿算法。
[Abstract]:High order modulation formats based on coherent optical communication coherent detection and digital signal processing technology, because it can achieve high spectral efficiency in electric domain to achieve transmission damage compensation and other advantages, become the development direction of next generation high speed optical communication system. This paper combined with the National 863 project "160Gb/s one pump multi fiber optical transmission technology study on" and the Canadian natural science fund fund project "'Digital signal processing strategy for fiber optic communication", focusing on polarization multiplexing 16 quadrature amplitude modulation (DP-16QAM) based on the code type, coherent optical communication system coherent detection and digital signal processing technology has been studied both theoretically and experimentally. The main research achievements are as follows:
1. proposed an improved four level scheme of signal generation, the generation of high quality 14Gbaud/s, 28Gbaud/s, 32Gbaud/s, 40Gbaud/s four level signal. Experimental study of DP-16QAM transmitter performance improved four level signal generation scheme based on the experimental results show that the optical signal-to-noise ratio of 2.7dB and 3.5dB were only 112Gb/s and 224Gb/sDP-16QAM transmitter performance with the theoretical value the price (OSNR). Set up the 112Gb/s DP-16QAM experimental transmission system, experimental study on the transmission performance. The experimental results show that the fiber dispersion compensation only single channel 112Gb/s DP-16QAM transmission system optimal input power is -3.5dBm; the forward error correction encoding (FEC) threshold is 3.8 * 10-, the implementation of the 112Gb/sDP-16QAM signal 1470km transmission.
2. the development of a complete set for DP-16QAM coherent receiver digital signal processing algorithm, including IQ non orthogonal compensation algorithm based on Gram-Schmidt orthogonal rule; dispersion compensation algorithm based on frequency domain equalizer; digital clock recovery; polarization multiplexing signal multiplexing and dynamic equilibrium; carrier frequency offset estimation and compensation; estimation and compensation carrier phase noise; judgment and error calculation. Simulation and experiment to verify the performance of the whole digital signal processing algorithm for the first time. The performance experiment of IQ non orthogonal compensation algorithm based on Gram-Schmidt orthogonal rule in DP-16QAM system.
3. the study of the transmission based on digital reverse (DBP:Digital Back-Propagation) of the optical fiber nonlinear compensation technology used in optical communication systems DP-16QAM long distance coherent analysis. The nonlinear effect of optical fiber polarization multiplexing transmission system. Simulation and Experimental Research on two key parameters, weighting coefficient and compensation step results showed: the compensation technology for transmission a specific system, the weighting coefficient DBP of compensation step, input power, transmission distance is not sensitive. The compensation performance and calculation considering the complexity under the condition of distance relay optimal compensation step DBP long transmission system. The compensation technology, 112Gb/s DP-16QAM long transmission system optimal input power is to enhance the 2dB; when the FEC threshold is 3.8x10-, experimental realization of the 112Gb/s DP-16QAM signal 2400km transmission, far transmission distance than not using the technology of lifting Near 63%.
4. proposed three improved four phase shift keying (MP) partition algorithm based on cascaded carrier phase noise estimation (CPE) algorithm. The algorithm of line tolerance degree, phase noise estimation, linear and nonlinear transmission performance and hardware complexity. Simulation and experimental results show that the three algorithms are search and performance blind phase (BPS) algorithm similar hardware complexity than BPS algorithm were decreased by 1.5-10 times.
5. in order to further reduce the hardware complexity, this paper proposes a cascaded CPE algorithm based on quasi zero multiplier algorithm. The results of simulation and experimental studies show that the cascade CPE algorithm line tolerance degree, phase noise estimation, linear and nonlinear transmission performance with BPS algorithm, but the algorithm hardware complexity than BPS algorithm reduces 17 times, is reported to date for the 16QAM modulation code the hardware complexity of the minimum feedback cascade CPE algorithm.
6. this paper presents the application of linear interpolation algorithm for carrier phase noise compensation technique, is proposed based on linear phase interpolation (LPI) enhanced carrier phase noise compensation algorithm, study the performance of the compensation algorithm in theory and experiment. The simulation and experimental results show that the LPI algorithm and sliding window (SW) is better than the performance of the compensation algorithm. The average data block (BA) compensation algorithm; however LPI algorithm hardware complexity and is similar to that of the BA algorithm is much lower than the SW compensation algorithm.

【学位授予单位】：北京交通大学
【学位级别】：博士
【学位授予年份】：2014
【分类号】：TN929.1

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