基于小波降噪和改进ISFA的CO-OFDM信道估计方法

Channel Estimation Method Based on Wavelet and Improved ISFA for CO-OFDM Systems

提出了一种基于小波降噪与改进的符号内频域平均(ISFA)联合的相干光正交频分复用(CO-OFDM)系统信道估计方法。该方法利用最小二乘(LS)方法进行信道估计,并对估计后的结果进行小波去噪处理,最后采用Kaiser窗函数改进ISFA算法对小波处理结果进行ISFA,完成联合去噪。仿真结果表明,该方法可以有效地提高信道估计精度。当光信噪比(OSNR)为17 d B时,该算法的误码性能(BER)比ISFA算法的误码性能提高将近一个量级。

A joint method of coherent optical orthogonal frequency division multiplexing （CO-OFDM） channel estimation based on wavelet denoising and improved intra-symbol frequency domain average （ISFA） is proposed. This method can be divided into three steps. Firstly, channel estimation is performed by least square （LS） method; secondly, the wavelet denoising processing is made for the results of estimation; finally, ISFA algorithm improved by Kaiser-window function is applied to the wavelet processing results. The simulation results show that the proposed method can effectively improve the precision of channel estimation. When the optical signal-tonoise ratio （OSNR） is 17 dB, bit error rate （BER） performance of the proposed method can be improved nearly one order of magnitude than that of ISFA method.