CAJ | 학술논문

基于隐含导频、超奈奎斯特镜像混叠和直接检测，首次在IM／DD光通信系统中使用基于隐含导频（ ST）的信道估计和均衡方式，通过实验实现了速率为20 Gb／s的正交相移键控（ QPSK）离散傅里叶变换扩展正交频分复用（ DFT-S-OFDM）信号传输83.2 km的光通信系统．使用隐含导频信道估计（ ST-CE）方法来均衡信道的线性损伤，关键是把隐含导频（ ST）算术叠加在数据信号上，而不占用单独的时隙．通过对接收到的信号进行1阶统计分析估计出精确的信道．为了增加传输距离，根据超奈奎斯特镜像混叠的方法增加接收机带宽来补偿色散引起的功率衰落．结果显示，在长距离强度调制／直接检测（ IM／DD） DFT-S-OFDM无源光网络（ PON）系统中，采用ST-CE能得到更高的频谱效率，且其信道估计性能与TA-CE相当．该方法节省了带宽，提高了频谱利用率．
기우은함도빈、초내규사특경상혼첩화직접검측，수차재IM／DD광통신계통중사용기우은함도빈（ ST）적신도고계화균형방식，통과실험실현료속솔위20 Gb／s적정교상이건공（ QPSK）리산부리협변환확전정교빈분복용（ DFT-S-OFDM）신호전수83.2 km적광통신계통．사용은함도빈신도고계（ ST-CE）방법래균형신도적선성손상，관건시파은함도빈（ ST）산술첩가재수거신호상，이불점용단독적시극．통과대접수도적신호진행1계통계분석고계출정학적신도．위료증가전수거리，근거초내규사특경상혼첩적방법증가접수궤대관래보상색산인기적공솔쇠락．결과현시，재장거리강도조제／직접검측（ IM／DD） DFT-S-OFDM무원광망락（ PON）계통중，채용ST-CE능득도경고적빈보효솔，차기신도고계성능여TA-CE상당．해방법절성료대관，제고료빈보이용솔．
An 83.2-km, 20-Gb/s QPSK DFT-S-OFDM PON based on superimposed training (ST), super-Nyquist image induced aliasing, and direct detection ( DD) is first experimentally demonstrated using superimposed train-ing-aided channel estimation (ST-CE) and equalization.Instead of training-aided channel estimation (TA-CE), the linear impairments of the channel using superimposed training without any bandwidth loss is equalized.The idea of ST-CE is that the training sequences ( TS ) are arithmetically added to the information symbols instead of being placed in separate exclusive time slots.Accurate CE is obtained by using the first-order statistics of the received signals.To further increase the reachable distance, the receiver bandwidth is slightly increased and super-Nyquist image induced aliasing to compensate the dispersion induced power fading is used.Results show that the superim-posed training channel estimation ( ST-CE) achieve similar estimation performance as that of the TA-CE method in a long reach IM/DD DFT-S-OFDM passive optical network ( PON) system, without compromising its spectral effi-ciency.This method can save bandwidth, and improve the utilization of the spectrum.