基于apFFT的罗兰-C窄带干扰频域抑制方法

Cancelation of Narrow-Band Interferences in Loran-C ReceiversUsing an Adaptive Notch Based on apFFT

摘要:

针对现有罗兰-C接收机普遍采用固定陷波电路抑制窄带干扰的情况,提出了基于全相位谱分析(apFFT)的频域精确自适应陷波罗兰-C窄带干扰抑制方法,设计了基于双相移组合全相位法的FIR频域陷波器。在对窄带干扰进行精确谱分析的基础上,设计相应频点的陷波器对多个窄带干扰进行抑制。基于MATLAB的仿真结果表明:该方法能够根据罗兰-C窄带干扰频率的变化,实现频点任意控制的频域自适应陷波,有效恢复出罗兰-C信号,为增强型罗兰-C接收机的设计提供了一种简单有效的窄带干扰抑制方法。

Abstract:

A new method for canceling narrow-band interferences signals in Loran-C receivers was presented. The system which was called an accurate frequency adaptive interference canceller was based on a novel notch filter designed by all-phase double phase shift combination algorithm. After spectrum analysis of signals, a notch filter was designed automatically to cancel more than three narrow-band interferences which had arbitrary frequencies. Computer simulation of the new method was completed with MATLAB, showing that the system realized accurate frequency adaptive interference cancellation of received signal. The efficient and simple method for canceling narrow-band interferences would be of direct use to the designers of enhanced Loran-C receivers.