低信噪比下脉冲重复周期渐变波形的相推测速实现  

A Phase-Derived Velocity Measurement Method for Variable Pulse Repetition Interval Waveform under Low SNR

作　　者：李文吉 任丽香[1,2] 范花玉 毛二可 LI Wenji;REN Lixiang;FAN Huayu;MAO Erke(Radar Research Lab,School of Information and Electronics,Beijing Institute of Technology,Beijing 100081,China;Key Laboratory of Electronic and Information Technology in Satellite Navigation(Beijing Institute of Technology),Ministry of Education,Beijing 100081,China)

机构地区：[1]北京理工大学信息与电子学院雷达技术研究所,北京100081 [2]卫星导航电子信息技术教育部重点实验室(北京理工大学),北京100081

出　　处：《信号处理》2021年第2期159-166,共8页Journal of Signal Processing

基　　金：国家自然科学基金项目资助(31727901,61771050,61671065)。

摘　　要：相推测速技术可以实现相位量级的测量精度,但是其存在准确提取相位和解相位模糊两大难点。本文提出了针对低信噪比条件下脉冲重复周期渐变波形的相推测速实现方法。首先,建立了考虑脉冲重复周期渐变波形的回波模型;然后介绍了基于包络测速解相位模糊的相推测速模型;进而为了提高相推测速在低信噪比条件下的适用性,分别提出了回波相位提取值修正以及相位模糊数修正方法,其中回波相位提取值修正方法主要结合航迹平滑滤波处理,解决低信噪比条件下峰值点相位提取不准确的问题,而相位模糊数修正方法通过遍历模糊数,并最小化模糊数对应的测速起伏误差;最后通过仿真验证了所提方法的正确性及其在低信噪比条件下的适用性。Phase-derived velocity measurement(PDVM) can obtain phase level measurement accuracy, but there are two difficulties in extracting the echo phase and resolving the phase ambiguity. In this paper, a phase-derived velocity measurement method is proposed for the variable pulse repetition interval waveform under low signal-to-noise ratio(SNR). Firstly, an echo model is established with considering the factor of pulse repetition interval variable. Then, the PDVM model based on wideband envelope velocity measurement(WEVM) to solve the phase ambiguity is introduced. In order to improve the applicability of PDVM method under the condition of low SNR, the extracted echo phase value correction method and the phase ambiguity number correction method are put forward respectively. The extracted echo phase value correction method utilizes the track filtering process to smooth the velocity measurement results, which enable to solve the problem of inaccurate extracted peak phase under low SNR. The phase ambiguity number correction method iterates through the phase ambiguity number and then minimizes the corresponding velocity fluctuation measurement error. Finally, the validity of the proposed method and its applicability under low SNR are verified by simulation.

关 键 词：包络测速 相推测速 脉冲重复周期渐变 低信噪比 

分 类 号：TN957.51[电子电信—信号与信息处理]