CO-OFDM通信系统中高效相位噪声补偿算法研究

发布时间：2017-12-28 09:14

本文关键词：CO-OFDM通信系统中高效相位噪声补偿算法研究　出处：《浙江工业大学》2015年硕士论文　论文类型：学位论文

【摘要】：相干光正交频分复用(CO-OFDM)具有优秀的抗色度色散与抗偏振模色散能力,是未来超高速、长距离光传输系统的强有力竞争方案之一。然而,相干解调对于系统中的激光相位噪声十分敏感,因为随机的相位转动会导致公共相位误差与载波间干扰,这是相干光正交频分复用系统研究的焦点之一。本论文围绕CO-OFDM通信系统中影响传输质量的噪声及其应对方案展开研究,重点研究了抑制系统公共相位噪声与载波间干扰的各种算法。通过仿真研究对比分析了各算法的优缺点,改进并提出了新的算法。本文的主要研究内容与成果如下:1)本论文简单介绍了CO-OFDM通信系统的应用背景,技术优势与研究现状。对相关技术原理,特别是对研究中所用到的专业知识做了必要的阐述。2)利用Opti System软件构建了一个CO-OFDM的仿真通信系统,结合matlab模块实现、仿真并研究了多种噪声抑制算法,通过大量图表数据分析对比了其优缺点。3)针对CO-OFDM通信系统中的公共相位噪声,提出了一种无迭代的盲估计算法。算法巧妙地构建了一个无限接近三角函数的代价函数,从而利用三角函数解析式的特征,通过少数取值点解出相位误差值,避免了其他盲算法常用的复杂迭代计算。大量仿真数据证明,无迭代的盲算法也能够有效地补偿相位误差。4)针对CO-OFDM通信系统中的载波间干扰噪声,提出了一种判决辅助的时域均衡算法,巧妙地将频域预判决与时域分组均衡这两种方法结合。提出判决门限,只使用正确概率高的判决数据,从而减少错误判决被采用的次数。在10Gbit/s的16QAM CO-OFDM系统进行了数据仿真,本算法可以有效地补偿系统中的ICI噪声。在较高激光器线宽与高光信噪比的条件下,本算法有明显优于同类时域ICI均衡算法(Avg-BL-ICI)的性能而额外开销不多。
[Abstract]:Coherent optical orthogonal frequency division multiplexing (CO-OFDM) has excellent ability to resist chromatic dispersion and anti polarization mode dispersion. It is one of the strong competitive schemes for ultra high speed and long haul optical transmission systems in the future. However, coherent demodulation is very sensitive to the laser phase noise in the system, because random phase rotation leads to common phase error and intercarrier interference, which is one of the focuses of coherent optical orthogonal frequency division multiplexing system. In this paper, we focus on the noise affecting the transmission quality in CO-OFDM communication system and its countermeasures. We focus on various algorithms to suppress common phase noise and intercarrier interference. The advantages and disadvantages of each algorithm are compared and analyzed through simulation research, and a new algorithm is improved and proposed. The main contents and achievements of this paper are as follows: 1) this paper briefly introduces the application background, technical advantages and research status of CO-OFDM communication system. The relevant technical principles, especially the specialized knowledge used in the study are expounded. 2) using Opti System software to build a CO-OFDM simulation communication system. Combined with MATLAB module, we implemented, simulated and studied a variety of noise suppression algorithms, analyzed and compared their advantages and disadvantages through a large number of charts and data. 3) aiming at the common phase noise in the CO-OFDM communication system, a non iterative blind estimation algorithm is proposed. The algorithm constructs a cost function which is infinitely close to trigonometric function, so that the phase error value can be solved by using the characteristic of the trigonometric function analytic formula and a few value points, avoiding the commonly used complex iterative computation of other blind algorithms. A large number of simulation data show that the non iterative blind algorithm can also effectively compensate the phase error. 4) aiming at the inter carrier interference noise in CO-OFDM communication system, a decision aided time domain equalization algorithm is proposed, which combines the two methods of frequency domain pre judgement and time domain packet equalization skillfully. The decision threshold is proposed, only the correct probability of the decision data is used to reduce the number of times the error decision is used. The data simulation is carried out in the 16QAM CO-OFDM system of 10Gbit/s. This algorithm can effectively compensate the ICI noise in the system. In the condition of high laser linewidth and high optical signal-to-noise ratio, this algorithm is obviously superior to the similar ICI time domain equalization algorithm (Avg-BL-ICI) and the performance overhead is not much.
【学位授予单位】：浙江工业大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TN929.53

【相似文献】