王锦仁

摘  要： 传统的检测方法在检测光正交频分复用系统的定时同步这一问题上，花费的检测时间过长，成本过高。针对上述问题，设计一种新的检测技术，该检测技术可以应用于光正交频分复用系统的直接检测中。检测技术由两步组成，首先进行光正交频分复用系统的信道同步直接检测，通过噪声补偿辅助判断信道是否同步;然后进行光正交频分复用系统的时间频率同步直接检测，计算出各子载波的相位旋转，由计算结果确定检测结果;最后实现定时同步检测。为检测方法效果，与传统检测技术进行实验对比，结果表明，给出的应用于直接检测光正交频分复用系统的定时同步技术可以在短时间内精准地检测出光正交频分复用系统是否定时同步，检测成本更低，该技术值得大力推广使用。

关键词： 定时同步检测; 光正交频分复用系统; 直接检测; 信道同步; 时间频率同步; 对比验证

中图分类号： TN913?34                             文献标识码： A                      文章编号： 1004?373X（2020）08?0089?04

Design of timing synchronization applied to direct detection of optical orthogonal frequency division multiplexing system

WANG Jinren

（Shijiazhuang Tiedao University Sifang College， Shijiazhuang 051132， China）

Abstract： Traditional detection methods spend too much time and cost in detecting the timing synchronization in the optical orthogonal frequency division multiplexing （OFDM） system. Therefore， a new detection technology is designed， which can be applied to the direct detection of optical OFDM system. The detection technology consists of two steps： the channel synchronization of the optical OFDM system is detected directly， and the noise compensation is used as an auxiliary means to judge whether the channel is synchronized or not; the time?frequency synchronization of the optical OFDM system is detected directly， the phase rotation of each subcarrier is calculated， and the detection results are determined according to the calculated results， so as to the timing synchronization detection is realized. The experimental comparison between the proposed method and the traditional detection technology was carried out to detect their detection effectiveness. The experimental results show that the timing synchronization technology applied to direct detection of the optical OFDM system can accurately detect whether its timing synchronization or not in a short time， and the detection cost is lower. The detection technology is worth spreading and using.

Keywords： timing synchronization detection; optical OFDM system; direct detection; channel synchronization; time?frequency synchronization; comparison validation

0  引  言

随着互联网快速发展，人们对数据业务要求大幅增高，尤其是传输速率方面，建立高速、高容量的传输数据网十分必要，而数据网的建立又依赖于各种系统的支撑。其中，光正交频复用系统是一种新型系统，该系统在速度、容量方面的优点极为突出，被大量应用于宽带数字通信领域[1]。该系统利用物理层进行多载波调制技术传输，对同步误差非常敏感，易受到码干扰和信道间干扰，可能严重损害系统性能，甚至引起整个系统的崩塌[2]。……