电力线扩频通信中窄带干扰的自适应抑制

Suppression of Narrowband Interference in Spread Spectrum Communications on Power Lines

利用电力线进行扩频通信时，需要抑制信道中的多个大功率、ＳＳＢ调制的窄带干扰。本文提出了两种能够有效抑制上述窄带干扰的自适应算法。一种是时域的自适应非线性滤波算法，它以自适应线性预测为基础，同时针对预测噪声呈非高斯分布的特性引入一个非线性修正算子，使得收敛时的"额外均方误差"小于传统的线性预测算法；另一种则是基于ＳＴＦＴ（短时付立叶变换）的频域自适应滤波算法，它遵循了变换域自适应滤波的基本思想，结合了频域限幅器与时域自适应滤波两者的优点，具有比时域处理更快的收敛速度。

It is necessary to suppress multiple SSB narrowband interference when the power lines are to be used for the transmission of spread spectrum signals. Two approaches have been put forward in this paper to solve the problem mentioned above. One is a nonlinear adaptive filtering algorithm implemented in time domain. Considering the non-Gaussian noise background, it takes linear adaptive prediction as the basis and introduces some nonlinear modifications as well. The other involves an adaptive filtering algorithm performed in spectrum domain. Derived from the fundamental theory of transform domain filtering, it possesses a faster adaptive convergence rate compared with that can be acquired in time domain.