一种改进的ISFA信道估计算法

An improved ISFA channel estimation algorithm

设计了一种基于符号内频域平均(ISFA)的信道估计算法,用于偏振复用光正交频分复用(PDM-O-OFDM)系统的信道估计和传输信道色散损伤的均衡。算法采用凯撒窗函数对基于导频的ISFA算法进行改进,提高了信道估计后处理的精度,改善了长距离PDM-O-OFDM系统的误码率(BER)和光信噪比(OSNR)性能。通过仿真试验,确定了算法的相关参数,分析了算法对长距离系统中色散损伤的均衡性能。仿真结果表明,改进算法对于传输距离超过700km系统的均衡效果优于原算法,其中900km处的OSNR代价比原算法低0.35dB。

A channel estimation algorithm is designed based on intra-symbol frequency-domain averaging （ISFA） method to estimate and equalize the dispersion impairments of polarization division multiplex optical orthogonal frequency division multiplexing （PDM-O-OFDM） system. The proposed channel estima- tion algorithm is improved from pilot-based intra-symbol frequency-domain averaging algorithm by Kaiser Window function. The improved algorithm can increase accuracy of post channel estimation processing,and can improve the bit error rate （BER） and optical signal to noise ratio （OSNR） of long haul PDM-O-OFDM system. The parameters of the algorithm are determined by means of simulation test, and the equalization performance of long haul dispersion impairments is analyzed. The simulation results show that the proposed algorithm is better than the original algorithm when propagating distance is longer than 700 km,and has a 0. 35 dB lower OSNR penalty than the original algorithm at 900 km.