摘要：

宽带线性调频(LFM)信号较大的工作带宽会对传统数据处理造成压力。为此,提出一种在空间欠采样条件下对LFM信号进行二维波达方向估计的方法。根据分数阶傅里叶变换对宽带LFM信号的能量聚集特性,将信号源分离为平稳单频信号,并建立一种新的空间时频数据模型。 在此基础上,构建空间均匀圆阵对入射信号进行处理,然后运用整数搜索法实现接收信号俯仰角和方位角的无模糊估计。仿真结果表明,相比非均匀L阵的阵列形式,该方法能够有效提升估计精度,降低计算量和运算复杂度。

关键词: 均匀圆阵, 线性调频信号, 分数阶傅里叶变换, 二维波达方向估计, 整数搜索法

Abstract:

The wide bandwidth of wide-band Linear Frequency Modulation (LFM) signals will cause pressure on traditional data processing.To slove this problem,a method of 2-D DOA estimation for wide-band LFM signals with spatial under-sampling is proposed.Based on the energy aggregation characteristic of the Fractional Fourier Transform(FRFT) on the wide-band LFM signals,the signals source is separated into a stationary single frequency signal,and a new spatial time frequency data model is established.On this basis,a spatial Uniform Circular Array(UCA) is constructed to process the incident signal,and then the integer search method is used to estimate the pitch angle and azimuth of the received signal. Simulation results show that compared with the array form of non-uniform L arrays,the proposed method can effectively improve the estimation accuracy,reduce computation complexity and computational complexity.

Key words: Uniform Circular Array(UCA), Linear Frequency Modulation (LFM) signals, Fractional Fourier Transform(FRFT), 2-D Direction of Arrival (DOA) estimation, integer search method

中图分类号: 

• TN911.7