摘要
分布式干涉天线阵列可利用多个天线同时接收信号的方式来增强探测灵敏度。但在对多路信号进行相参合成以提升信噪比前,需要先将接收到的信号经历的时差和频差进行有效检测和补偿。在进行信号的频差补偿时,由于傅里叶变换固有的频谱泄露以及“栅栏效应”,会限制对到达各接收站信号的频差估计精度。针对此问题,文章提出了一种窗函数长度搜索频差估计算法,可在较低信噪比下将均方根误差从1kHz降低为30Hz以内。基于所提算法完整演示了四路信号的相参合成,信噪比提升5.79dB(理论值6dB),证明了算法的有效性和优越性。
Distributed interferometric antenna arrays leverage simultaneous multi-antenna receptions to enhance detection sensitivity.Before phase-coherent signal combination for Signal-to-Noise Ratio(SNR)improvement,it is essential to accurately detect and compensate for time and frequency differences among the signals.The accuracy of frequency difference estimation at the receivers is inherently limited by the spectral leakage and grating lobe artifacts of the Fourier transform.This work proposes a method for optimizing the window function length in frequency difference estimation,reducing the Root Mean Square Error(RMSE)from 1kHz to under 30Hz in low SNR conditions.The algorithm's validity and superiority are demonstrated through the coherent combination of four signals,achieving an SNR improvement of 5.79dB(close to the theoretical gain of 6dB).
作者
徐睿琦
魏伟
谢玮霖
董毅
XU Ruiqi;WEI Wei;XIE Weilin;DONG Yi(Key Laboratory of Photonic Information Technology,Ministry of Industry and Information Technology,School of Optics and Photonics,Beijing Institute of Technology,Beijing 100081,China;Yangtze Delta Region Academy of Beijing Institute of Technology,Jiaxing 314011,China)
出处
《光学技术》
北大核心
2025年第1期66-71,共6页
Optical Technique
基金
国家自然科学基金(62271058)。
关键词
到达频差
到达时差估计
信号相参合成
frequency of arrival
time of arrival differenceestimation
coherent signal combination
