偏振复用相干光OFDM系统信道估计技术研究
发布时间：2019-06-15 14:49
【摘要】：目前100 Gb/s速率的光.通.信系.统.已经投入市场使用,当前研究重点放到了100Gb/s以上的光通信系统。高速光通信系统中应用了偏振复用技术,使用偏振复用技术大大降低了系统对于色度色散(Chromatic Dispersion,CD)、偏振模色散(Polarization Mode Dispersion,PMD)这一系列劣化损伤的容忍度,信道估计和解偏振复用越来越难以实现。随着数字电路芯片制作工艺水平的提升,模数转换器(Analog to Digital Converter,ADC)所需达到的采样速率与光传输速率相匹配的要求逐步成为现实。利用相干光正交频分复用(Coherent Optical Orthogonal Frequency Division Multiplexing,CO-OFDM)不仅能增大接收机灵敏度,而且能够辅助数字信号处理(Digital Signal Processing,DSP)来抵抗光信道中的劣化,比如CD和PMD。在采用PDM-CO-OFDM技术的通信系统中的大部分DSP技术中,信道估计技术是其中非常重要的一门技术,是解偏振复用的首要任务。最小二乘(LS,Least Square)信道估计算法,是当前广泛使用的信道估计算法,其算法复杂度低,但抗噪声能力差,为了提高其精确度必须进行改进。现有的信道冲击响应(Channel Impluse Response,CIR)算法可以降低噪声对LS算法的破坏,但是仍然存在一些缺陷。本文研究了偏振复用相干光正交频分复用(Polarization Division Multiplexing Coherent Optical Orthogonal Frequency Division Multiplexing,PDM-CO-OFDM)传输系统。对信号和信道模型进行了分析,利用VPI Transmission MakerTM软件搭建了200 Gb/s速率的PDM-CO-OFDM光传输仿真平台。该传输平台可光纤信道的劣化进行仿真,例如CD、PMD、激光器线宽、ASE噪声等效应。利用VPI Transmission MakerTM以及MATLAB搭建了DSP算法仿真平台,在此平台上对现有的PDM-CO-OFDM光通信系统的信道估计算法进行了分析,并针对其局限性,提出了基于DFT算法的改进方案;此外,在PDM-CO-OFDM系统中引入了在图像处理领域很常用的离散余弦变换(Discrete Cosine Transform,DCT)并对DCT算法进行了改进,在VPI+MATLAB平台上得到了验证。
[Abstract]:The current rate of light at 100 Gb/s. Pass. Department of Information. Unified It has been put into use in the market, and the current research focuses on the optical communication system above 100Gb/s. Polarization reuse technology is applied in high speed optical communication system, and polarization reuse technology is used to greatly reduce the tolerance of chromaticity dispersion (Chromatic Dispersion,CD) and polarization mode dispersion (Polarization Mode Dispersion,PMD) to a series of deterioration damage. It is more and more difficult to realize channel estimation and polarization reuse. With the improvement of the fabrication technology of digital circuit chip, the requirement of matching sampling rate and optical transmission rate of analog-to-digital converter (Analog to Digital Converter,ADC) has gradually become a reality. Coherent Optical orthogonal Frequency Division Multiplexing (Coherent Optical Orthogonal Frequency Division Multiplexing,CO-OFDM) can not only increase the sensitivity of the receiver, but also assist digital signal processing (Digital Signal Processing,DSP to resist deterioration in optical channels, such as CD and PMD.. In most of the communication systems based on PDM-CO-OFDM technology, channel estimation technology is one of the most important technologies, and it is the primary task of depolarization reuse. The least squares (LS,Least Square) channel estimation algorithm is a widely used channel estimation algorithm at present. Its complexity is low, but its anti-noise ability is poor. In order to improve its accuracy, it must be improved. The existing channel impulse response (Channel Impluse Response,CIR) algorithm can reduce the damage of noise to LS algorithm, but there are still some defects. In this paper, the polarization multiplex coherent optical orthogonal frequency division multiplexing (Polarization Division Multiplexing Coherent Optical Orthogonal Frequency Division Multiplexing,PDM-CO-OFDM) transmission system is studied. The signal and channel model are analyzed, and the PDM-CO-OFDM optical transmission simulation platform at 200 Gb/s rate is built by using VPI Transmission MakerTM software. The transmission platform can simulate the deterioration of fiber channel, such as CD,PMD, laser linewidth, ASE noise and so on. The DSP algorithm simulation platform is built by using VPI Transmission MakerTM and MATLAB. On this platform, the channel estimation algorithm of the existing PDM-CO-OFDM optical communication system is analyzed, and an improved scheme based on DFT algorithm is proposed according to its limitations. In addition, the discrete cosine transform (Discrete Cosine Transform,DCT), which is commonly used in image processing, is introduced into PDM-CO-OFDM system and the DCT algorithm is improved, which is verified on VPI MATLAB platform.
【学位授予单位】：电子科技大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TN929.1
本文编号：2500301
[Abstract]:The current rate of light at 100 Gb/s. Pass. Department of Information. Unified It has been put into use in the market, and the current research focuses on the optical communication system above 100Gb/s. Polarization reuse technology is applied in high speed optical communication system, and polarization reuse technology is used to greatly reduce the tolerance of chromaticity dispersion (Chromatic Dispersion,CD) and polarization mode dispersion (Polarization Mode Dispersion,PMD) to a series of deterioration damage. It is more and more difficult to realize channel estimation and polarization reuse. With the improvement of the fabrication technology of digital circuit chip, the requirement of matching sampling rate and optical transmission rate of analog-to-digital converter (Analog to Digital Converter,ADC) has gradually become a reality. Coherent Optical orthogonal Frequency Division Multiplexing (Coherent Optical Orthogonal Frequency Division Multiplexing,CO-OFDM) can not only increase the sensitivity of the receiver, but also assist digital signal processing (Digital Signal Processing,DSP to resist deterioration in optical channels, such as CD and PMD.. In most of the communication systems based on PDM-CO-OFDM technology, channel estimation technology is one of the most important technologies, and it is the primary task of depolarization reuse. The least squares (LS,Least Square) channel estimation algorithm is a widely used channel estimation algorithm at present. Its complexity is low, but its anti-noise ability is poor. In order to improve its accuracy, it must be improved. The existing channel impulse response (Channel Impluse Response,CIR) algorithm can reduce the damage of noise to LS algorithm, but there are still some defects. In this paper, the polarization multiplex coherent optical orthogonal frequency division multiplexing (Polarization Division Multiplexing Coherent Optical Orthogonal Frequency Division Multiplexing,PDM-CO-OFDM) transmission system is studied. The signal and channel model are analyzed, and the PDM-CO-OFDM optical transmission simulation platform at 200 Gb/s rate is built by using VPI Transmission MakerTM software. The transmission platform can simulate the deterioration of fiber channel, such as CD,PMD, laser linewidth, ASE noise and so on. The DSP algorithm simulation platform is built by using VPI Transmission MakerTM and MATLAB. On this platform, the channel estimation algorithm of the existing PDM-CO-OFDM optical communication system is analyzed, and an improved scheme based on DFT algorithm is proposed according to its limitations. In addition, the discrete cosine transform (Discrete Cosine Transform,DCT), which is commonly used in image processing, is introduced into PDM-CO-OFDM system and the DCT algorithm is improved, which is verified on VPI MATLAB platform.
【学位授予单位】：电子科技大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TN929.1
【参考文献】
相关期刊论文 前1条
1 周一青,胡爱群;利用训练帧进行OFDM系统同步的新算法[J];通信学报;2001年04期
，本文编号：2500301
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