摘要
相干光正交频分复用(Coherent Optical Orthogonal Frequency Division Multiplexing,简称CO-OFDM)可有效降低光纤色散和偏振模色散影响,由于系统采用相干检测,对相位噪声的分析及信道估计尤为重要。文章对CO-OFDM系统数学模型进行了具体分析;OFDM作为一种特殊的多载波技术,利用训练序列以及插入导频来实现系统的相位估计,根据相位偏移及噪声分布,对系统相位估计实现进行了分析;通过数字仿真进一步加以验证理论推导及方案可行性。结果表明,CO-OFDM系统在光纤传输中,受到相位噪声影响系统性能下降,通过较为简单的相位估计,可有效均衡接收信号噪声影响。
Coherent optical orthogonal frequency-division multiplexing （CO-OFDM） has been demonstrated to combat fiber chromatic dispersion and polarization-mode dispersion （PMD） effectively. Because of coherent detection employed in CO-OFDM, it is important to analyze the optical phase noise and estimate phase evolution. The model of CO-OFDM systems is analyzed in the paper. OFDM systems transmit a data stream over a number of lower rate subcarriers simultaneously, which is an opportunity to employ advanced phase estimation techniques, such as pilot-aided and train-series phase estimation. Additionally, the approach to estimate phase evolution of OFDM signals based on laser phase drift and fiber chromatic dispersion is analyzed. Simulation demonstrates that system performance would be improved effectively with simple phase estimation.
出处
《电路与系统学报》
CSCD
北大核心
2011年第1期20-24,30,共6页
Journal of Circuits and Systems
基金
国家自然科学基金(60871075)
关键词
相干光通信
正交频分复用
相位估计
色散补偿
Coherent optical communications
orthogonal frequency division multiplexing
phase estimation
chromatic dispersion compensation
