Predistortion of Mach–Zehnder Modulator Using Symmetric Imbalance
Predistortion of Mach–Zehnder Modulator Using Symmetric Imbalance
复制标题
使用对称不平衡的马赫-曾德调制器预失真
DOI：
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发表时间：
2017
影响因子：
4.7
通讯作者：
D. Sadot
中科院分区：
文献类型：
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作者：
G. Paryanti;D. Sadot
马赫-曾德尔调制器（Mach-Zehnder Modulators，MZM）的缺陷严重限制了高速光纤通信链路中高阶调制信号（如M-QAM、光OFDM或M-PAM）的传输性能。提出了各种预失真方法来补偿MZM效应;然而，它们不能补偿所有类型的损伤，并且它们需要针对需要校正的每个附加损伤的大量计算资源。为了克服这些困难，提出了一种新的预失真方法。该方法是基于添加一个不平衡对称的信息应用到MZM武器。不平衡以对称不平衡和MZM损伤的总体影响通过均方误差最小化的方式对信号进行预失真。一个封闭的形式，以及一个优化方法，补偿所有MZM损伤与一个单一的和低复杂性的基础设施。分析包括浮点和定点，并考虑到数模转换器的影响。它示出的整体方法的性能是有限的，仅由数-模转换器的位数N，使MZM输出误差矢量幅度是有界的10- 6 N [dB]。
Impairments of Mach–Zehnder modulators (MZM) set a sever performance limit on transmitting high-order modulation signals such as M-QAM, optical OFDM or M-PAM in high-speed fiber optics communication links. Various predistortion methods were proposed for compensating MZM effects; however, they do not compensate for all types of impairments and they require significant computation resources for each additional impairment needed to be corrected. In order to overcome these difficulties, a new predistortion approach is proposed. The method is based on adding an imbalance symmetrically to the information applied to the MZM arms. The imbalance predistorts the signal in a way that the overall effect of the symmetric imbalance and MZM impairments is minimized by means of mean square error. A closed form as well as an optimization method that compensates for all MZM impairments with a single and low complexity infrastructure is presented. Analysis includes floating point as well as fixed point, considering digital to analog converter effects. It is shown that the overall method performance is limited only by the number of bits N of the digital-to-analog converter so that the MZM output error vector magnitude is bounded by 10-6N [dB].