中文摘要：

超低频通信下行信号接收端受空间、地形等条件约束，难以布设远端参考线圈，因此传统的自适应干扰压制方法难以获得良好的干扰抵消性能。为解决这一难题，基于自适应相关抵消的原理，针对超低频通信下行信号的接收，提出采用多参考线圈与主接收天线本地正交布设的方案设计探测系统，并研究了一种电磁干扰自适应抵消系统的实现方法。然后，以工频谐波干扰的抵消为例进行了测试，实测结果表明：对于与干扰频谱不相重合的微弱单音信号，在不同信号强度下，采用一种基于通道相关性的多通道可变遗忘因子自适应RLS滤波算法，信干比平均改善23．51dB，其最大增益可达25.87dB，平均信噪比增益为8．13dB，说明该系统能够有效压制超低频电磁干扰。

英文摘要：

As the downlink signal receivers of super low frequency （SLF） communication are restric- ted to space and terrain, it is unfeasible to lay remote reference coils. So it is not easy to obtain good performance for interference cancelling with the help of conventional methods. To solve this problem, a detection system with orthogonally placed multiple local reference coils and primary receiving antenna is established as far as the receiving SLF communication downlink signal is concerned. And a method of realizing the adaptive interference cancellation system is proposed based on the principle of adaptive correlation cancellation. Experiments of interference cancellation of real power line industrial frequency and its harmonics show that, when the weak signals are not in coincidence with interference frequencies, this system can obtain the signal-to-interference ratio gain of average 23.60 dB and maximal 25.33 dB, and signal-to-noise ratio gain of average 8.24 dB in different signal amplitudes by adopting recursive least squares algorithm, which indicates that the system is able to suppress SLF electromagnetic interference effectively.