罗兰C信号中的窄带干扰抑制与仿真

摘要

Narrow band interference（NBI） is a kind of interference which exists in loran-c signal which receiver receives.NBI often conceals loran-c signal,so it is very important for receivers＇ working normally.It adopts LMS adaptive algorithm and a daptive notch filter with 2-taps to process loran-c signal within NBI.From the simulation we could know that,LMS adaptive algorithm has an good effect on carrier wave interference and near carrier wave interference,but its implementing needs many taps and it is difficult to obtain expection signal because of coding information,Loran-c signal resulting is realizing difficultly.Two-tapped adaptive notch filter algorithm completely wipes off interference point,so it cann＇t be used to suppress carrier wave interference.However,it has a good effect on near-carrier wave interference and none-carrier wave interference,and its realization is very easy and is easy to used in project.%窄带干扰（NBI）是罗兰C接收机接收信号中普遍存在的一种干扰。这种窄带干扰经常淹没有用的罗兰C信号,因此,去掉NBI对罗兰C接收机的正常工作尤为重要。分别采用最小均方误差（LMS）自适应算法和二阶自适应格型滤波器算法对带有窄带干扰的罗兰C信号进行处理。仿真结果得出：LMS自适应滤波器对同步干扰和近同步干扰都有很好的效果;但是由于罗兰C信号本身的编码信息而比较难获取期望信号,加上LMS自适应滤波器实现阶数较高,实现相对困难。二阶格型自适应滤波器由于是完全除去干扰频率点,不能用于同步干扰,但其对近同步干扰和非同步干扰仍然有很好的效果,且其实现较为简单,易于在工程上应用。