一种采用光学相位分集接收技术的相干光正交频分复用远端接入系统

提出了一种采用基于光学相位分集接收技术实现远程相干光正交频分复用(CO-OFDM)信号的远程光接入方案,并进行了理论研究和仿真验证。在本方案中,没有使用色散补偿光纤(DCF)或者色散补偿模块(DCM)补偿光纤信道色散导致的负面效应,原因是CO-OFDM信号能有效抵抗传输过程中色度色散(CD)和偏振模色散(PMD)引起的负面效应。仿真结果表明,10Gbit/s CO-OOFDM信号在标准单模光纤(SMF-28)传输320km后,采用相位估计技术得到的OFDM电信号,其时域波形的相位抖动幅度更小;与采用光载波自提取技术接收相位调制COOFDM的方案进行比较,测试误差向量幅度(EVM)的结果表明,本文方案可以获得更好的COOFDM信号接收性能,星座图中星座点收敛更加紧凑,接收的CO-OFDM信号质量更高。

A CO-OFDM remote access system using optical phase diversity reception techniqu e

To solve the problem of quality deterioration of optical orthogonal frequency di vision multiplexing (OOFDM) signal after lo ng distance transmission due to the passive effects of chromatic dispersion (CD) and polarization mode dispersion (PMD) of f iber, a novel remote coherent optical orthogonal frequency division multiplexing (CO-OFDM) access system using optical phase div ersity receiver is proposed,theoretically analyzed,and demonstrated by simulation.In this scheme,the dispersion compens ation fiber (DCF) or the dispersion compensating module (DCM) for compensating chromatic dispersion negative effects from optical fiber channel has not been used,since CO-OFDM optical signal transmission can effectively resist the negative effect s caused by chromatic dispersion (CD) and polarization mode dispersion (PMD).Simulation results show that after transmiss ion of optical OFDM signal at 10Gbit/s over 320km SMF-28,the range of phase jitter of received electrical signal by using phase estimation is more limited.A comparison is made between this scheme and the phase modulation optical OFDM method based on s elf carrier extraction,and results show that by using optical phase diversity re ceiver and phase estimation simultaneously,b etter receiver performance can be obtained,the receiver constellation of OFDM signal is more compact,the EVM performance is be tter and the quality of received signal is higher. Hence,this scheme has potential application value for CO-OFDM signal remote a ccess system.