CAJ | 학술논문

采用中频数字化技术的塔康视频信号是离散的脉冲调幅信号，含有大量随机填充脉冲，占空比大。首先，针对峰值搜索提取包络的方法在低信噪比环境下效果差，提出一种新的数字包络检测算法，设计与脉冲相匹配的滤波器，通过检测匹配滤波器输出的最大相关峰值确定脉冲到达时刻，拟合整个脉冲估计其峰值得到包络信号；然后，用最小二乘算法拟合包络估计方位，通过残差分析以一定置信度剔除粗差；最后，对连续k个方位参数数据平滑得到最终的结果。在装备模拟器上的仿真实验表明，所提方法在0 dB功率信噪比下，能有效检测包络、估计方位信息，估计误差小于0．5°，满足系统精度要求。
채용중빈수자화기술적탑강시빈신호시리산적맥충조폭신호，함유대량수궤전충맥충，점공비대。수선，침대봉치수색제취포락적방법재저신조비배경하효과차，제출일충신적수자포락검측산법，설계여맥충상필배적려파기，통과검측필배려파기수출적최대상관봉치학정맥충도체시각，의합정개맥충고계기봉치득도포락신호；연후，용최소이승산법의합포락고계방위，통과잔차분석이일정치신도척제조차；최후，대련속k개방위삼수수거평활득도최종적결과。재장비모의기상적방진실험표명，소제방법재0 dB공솔신조비하，능유효검측포락、고계방위신식，고계오차소우0．5°，만족계통정도요구。
TACAN video signal based on Intermediate Frequency ( IF) digital technique is a discrete Pulse Amplitude Modulation ( PAM) signal,which contains plenty of random filling pulses with large duty ratio . Considering that the envelope extraction method through searching the pulse peaks is not effective at low SNR,a novel method of digital envelope detection was proposed .According to the definitive signal format,a matched filter was designed to determine the arrival time of pulse by detecting the maximum correlation peak .The pulse peak was estimated to get the envelop signal by fitting the whole pulse .Secondly,least square algorithm was used to estimate the bearing parameter .In order to reduce and restrain outliers,intolerable errors were eliminated on the basis of confidence through residual analysis .At last,the final result was obtained by smoothing acquired k bearing parameters .Its effectiveness was verified by the experiment results .Under the power SNR of 0 dB,the estimation error is less than 0.5°,which meets the requirement of TACAN system .