基于全通滤波器的IIR陷波器在抑制电力线通信中的谐波干扰的研究

The Study of Rejecting Harmonic Interference in Power Line Communication Using IIR Notch Filter Based on All-Pass Filter

从滤波器的系数敏感度出发 ,提出用基于全通滤波器的IIR陷波器来抑制电力线通信信号中的谐波干扰。详细论述了这种陷波器的设计方法 ,分析了其在低频段的系数敏感度。通过实际数据验证了这种滤波器能够有效地抑制电力线通信信号中的谐波干扰 ,大大提高了信噪比。

From the point of the coefficient sensitivity of filter,a method of eliminating harmonic interference in the signal of power line communication using infinite impulse response (IIR) notch filter based on all-pass filter is proposed.Due to the mirror-image symmetry relation ship between the numerator and denominator polynomials of transfer function of all-pass filter,the notch filter can be realized by a computationally efficient lattice structure.The filter has very low sensitivity that the notch frequency shift after coefficient quantization is the least.The design method of the filter is discussed in detail,and coefficient sensitivity in low frequency band is analyzed.Practical experiments proved that the filter eliminates harmonic interference and improves the signal-to-noise ratio effectively in power line communication.