基于全相位FFT的稳健型时间调制阵列测向  

Robust direction finding by time-modulated array with all phase FFT

作　　者：曹岸杰[1,2] 范迎春 王瀚霆 杜一凡 杨勇[1] 游月辉[1] CAO Anjie;FAN Yingchun;WANG Hanting;DU Yifan;YANG Yong;YOU Yuehui(Shanghai Institute of Satellite Engineering,Shanghai 200230,China;Shanghai Jiao Tong University,Shanghai 200240,China)

机构地区：[1]上海卫星工程研究所,上海200230 [2]上海交通大学,上海200240

出　　处：《电波科学学报》2022年第6期1000-1006,共7页Chinese Journal of Radio Science

基　　金：国家自然科学基金青年基金(62271317)。

摘　　要：基于谐波特征分析的时间调制阵列测向方法的正确性与精度严重依赖接收谐波的估计精度.传统的离散傅里叶变换(discrete Fourier transform,DFT)或快速傅里叶变换(fast Fourier transform,FFT)在估计谐波的幅相时,由于信号频率通常偏离采样频率的整数倍,会形成栅栏效应,从而引起基于谐波特征分析的时间调制阵列测向的精度降低甚至失效.针对该问题,本文将全相位FFT引入二单元时间调制阵列接收谐波的分析中,通过提升谐波幅相估计的鲁棒性来提升时间调制阵列测向方法的稳健性.仿真结果表明,当信号的载频为频谱分辨率的任意小数倍时,提出的全相位FFT时间调制阵列测向方法均能正确测向,且随着信噪比的增加,测向均方根误差收敛至0.本文工作提升了基于谐波特征分析的单通道时间调制阵列测向方法的稳定性.The effectiveness and accuracy of time-modulated array(TMA)based direction finding with harmonic characteristic analysis depend on the accuracy of harmonic estimation.During estimating the harmonic amplitudes and phases with conventional discrete Fourier transform(DFT)or fast Fourier transform(FFT),the fence effect generates if the carrier frequency of the received signal deviates the integer multiple of the frequency resolution.Therefore,it will decrease the accuracy of direction finding,even cause failure.According to this problem,this manuscript introduces the all-phase FFT into the analysis to received harmonics by the two-element TMA,which improves the robustness of estimation to amplitudes and phases of harmonics and the robustness of direction finding by TMA.Numeric simulations show that the proposed all-phase FFT direction finding method with time modulated array can acquire correct results,when the carrier frequency of the signal is any fractional multiple of the spectral resolution.And the root mean square error(RMSE)converges to 0 with the increase of SNR.This work improves the stability of the single-channel direction finding method with time modulated array based on harmonic characteristic analysis.

关 键 词：时间调制阵列(TMA) 无线电测向 全相位快速傅里叶变换(FFT) 离散傅里叶变换(DFT) 

分 类 号：TN821[电子电信—信息与通信工程]