一种基于频控阵预编码的干扰抑制技术

A type of interference suppression based on FDA precoding

目前阵列雷达目标探测技术大多依赖传统的相控阵技术,但其所产生的波束只与角度有关.而近年来频控阵(frequency diverse array,FDA)的提出,使得波束不仅与角度有关还与距离和时间有关.基于FDA技术,通过最大化接收信号的信噪比(signal-to-noise ratio,SNR)作为优化目标,提出了最优发射信号的预编码和FDA频偏的设计方法,从而把对其他无线设备的干扰降低到最小.预编码的设计使得FDA的波束在目标处产生一个角度-距离维上的孤立点,而FDA的优化算法是基于一种变种的梯度下降法,通过回溯法线性搜索出最佳迭代步长.数值仿真结果显示,该算法成功地在目标处产生了点状波束,且算法可在10次以内完成收敛,从而可以在角度-距离维进行干扰抑制.

Conventional radar with phased-array antenna can only generate angle-dependent beam patterns.While recent proposed frequency diverse array(FDA)can generate beam patterns associated with angle,range and time.Based on the technology of FDA,we propose an optimal precoder and frequency offsets for FDA to lower the interference of FDA radar to other radio systems by maximizing the received signal-noise-ratio.The design of FDA precoder makes its beam pattern as an isolated point in angle-range domain,while the proposed optimization algorithm based on a reconstructed gradient descent method,wherein the step size is obtained by backtracking line search method.Numerical simulation shows that the proposed method can generate a point beam pattern at the target and the algorithm can converge within 10 iterations.Therefore,the proposed method can effectively reduce the interference in angle-range domain.