基于分数阶傅里叶四阶中心矩的尺度差/时差估计  

SDOA/TDOA Estimation Based on Fractional Fourier Fourth Order Central Moment

作　　者：黄清顺 邓兵 HUANG Qingshun;DENG Bing(Naval Aviation University Shore Defense College Graduate brigade,Yantai,Shandong 264001,China;Radar Teaching and Research Department,School of Combat Operations,Naval Aviation University,Yantai,Shandong 264001,China)

机构地区：[1]海军航空大学岸防学院研究生大队,山东烟台264001 [2]海军航空大学战勤学院雷达教研室,山东烟台264001

出　　处：《信号处理》2021年第1期111-119,共9页Journal of Signal Processing

基　　金：国家自然科学基金项目(61571454)。

摘　　要：针对大瞬时宽带线性调频信号的时差/尺度差在低信噪比下估计精度下降和算法运算量大的问题。本文利用时频轴旋转、魏格纳分布和模糊函数的关系推导出分数阶傅里叶四阶中心矩和尺度差的关系式,通过寻找两路信号的分数阶傅里叶四阶中心矩在角度域的位置,即可获得尺度差的估计值。将估计的尺度差对一路信号进行伸缩,并计算伸缩后信号与另一接收信号的时域相关,根据相关峰的位置估计出时差,并对本文算法抗噪性进行定性推导。仿真结果表明,相比于分数阶傅里叶尺度变换时差/尺度差估计算法,本文算法提高了在低信噪比下时差/尺度差估计精度,并对算法抗噪性定量分析得出本文算法抗噪性更好。Aiming at the problem of the time difference of arrival(TDOA)/the scale difference of arrival(SDOA)about the large instantaneous wideband chirp signals,the estimation accuracy is reduced and the algorithm calculation is large under the low signal-to-noise ratio.This paper uses the relationship between time-frequency axis rotation,Wigner distribution and ambiguity function to derive the relationship between the fractional Fourier fourth-order central moment and the SDOA,By finding the position of the central moment of the fractional Fourier fourth-order of the two signals in the angle domain,the SDOA can be estimated.The estimated SDOA is stretched to one signal,and the time domain correlation between the stretched signal and another received signal is calculated,and the TDOA is estimated according to the position of the correlation peak,and qualitatively derive the noise resistance of the algorithm in this paper the simulation results show that compared to TDOA/SDOA estimation algorithm based on the fractional Fourier scaling transform,The algorithm in this paper improves the estimation accuracy of time difference/scale difference under low signal-to-noise ratio,and quantitatively analyzes the anti-noise performance of the algorithm.The algorithm in this paper has better anti-noise performance.

关 键 词：四阶中心矩 宽带互模糊函数 尺度差/时差估计 宽带线性调频信号 分数阶傅里叶变换 

分 类 号：TN958.97[电子电信—信号与信息处理] TN971.1[电子电信—信息与通信工程]