一种基于递归QRD-LS算法的同频干扰消除方法

A Method of Adaptive Suppression for Same Frequency Interference Based on Recursive QRD-LS Algorithm

同频干扰(收发天线的直接耦合波,表面直接发射波)由于其具有很强的能量对近场瞬态主动电磁探测系统的目标信号造成了严重的干扰,此干扰与目标回波信号同频且强度往往高于目标回波信号,因此,对探测系统的正常工作危害极大。本文分析了传统的同频干扰消除方法,阐述了自适应RLS(递归最小二乘法)滤波的原理,在此基础上提出了一种基于QRD-LS算法的同频干扰消除方法。该方法收敛速度快、运算量较小、能实现实时的信号处理。计算机仿真结果表明该方法可有效抑制同频干扰,提高了目标回波的信干比(SIR)。同时该方法对同频干扰的局部畸变以及幅度、时延的变化具有很强的适用性。

The same frequency interference（including direct coupling wave of receiving and transmitting antennas, direct surface reflection wave）, because of its strong energy, has great effect on the target signal of a near field transient active electromagnetic detection system. This interference has the same frequency as target signal,and is generally bigger than the target signal. Therefore, it is great harm to the detection system＇s normal operation.In this paper, the traditional methods of same frequency interference elimination are analyzed,and the working principle of adaptive RLS（recursive least square） filter is presented, then a new method of same frequency interference suppression which is based on recursive QRD-LS algorithm is put forward. The method has fast convergence speed, low operation amount and can realize real-time processing. The simulation results show that this method can effectively suppress the same frequency interference, and improve the SIR（signal to interference radio） of the target signal. Moreover, the method has a good applicability for the local aberration of the same frequency interference and the changes of its amplitude and time-delay.