受多种光纤非线性因素的影响，基于正交频分复用(OFDM)技术的无源光网络(PON)会受到较为严重的载波间干扰(ICI)。为了抑制OFDM-PON系统中的上述问题，构造了一种新的伪对称序列(PST)，并提出将该问题转化为求解两个Toeplitz子系统，然后对其中一个子系统的解进行预处理，将其转化为另一子系统的输入，之后利用最小二乘准则对子系统求解，从而达到抑制载波间干扰的目的。在算法实现过程中，利用所构造序列的伪对称特性和快速傅里叶变换(FFT)，避免了高阶矩阵直接求逆，从而提升了算法实时性。仿真结果表明，该方法不仅能够有效抑制OFDM-PON系统的载波间干扰，而且能有效提升该算法的实时性能。

The inter-carrier interference (ICI) in passive optical network (PON) systems based on orthogonal frequency division multiplexing (OFDM) technology is resulted in seriously by kinds of fiber nonlinear factors. An algorithm based on the pseudo-symmetrical training (PST) sequences is proposed to solve the problem; two Toeplitz sub-systems which are transformed from the mentioned problem are to be solved. The input of the second sub-system is achieved by pre-processing the first sub-system. As a result, the output of the second sub-system can be achieved based on least square (LS) criterion. At last, the suppression of ICI can be achieved. The characteristic of PST sequences and fast Fourier transform (FFT) are introduced into the proposed algorithm refraining from traditional high order inversion. As a result, the real-time performance of the calculation is improved. Simulation results show that the proposed algorithm for OFDM-PON systems can not only suppress ICI, but also improve the real-time performance dramatically.