摘要
研究线性调频连续波在水下探测中的信号模型、回波信号的检测和目标参数估计方法,通过分析回波信号与发射信号间的差拍信号,提出差拍-分数阶傅里叶变换结构的处理算法。为了减少分数阶傅里叶变换二维搜索时的计算量,首先使用Radon-Ambiguity变换估计差拍信号的调频斜率,再做相应阶次的分数阶傅里叶变换。数值仿真说明提出的算法能够有效消除线性调频连续波的距离-速度耦合现象,准确估计目标参数。通过湖上试验比较线性调频脉冲信号和线性调频连续波的处理增益,提出的算法处理的连续波比匹配滤波方法处理的脉冲信号处理增益大13 dB。研究结果表明该算法在连续波水下探测中可行有效,不仅能够准确估计目标参数,还具有良好的检测性能。
The model of Linear Frequency Modulation Continuous Wave （LFMCW） applied in underwater detection and the method for the detection of echo signal and the estimation of target parameters are studied. By analyzing the heterodyne signal, an algorithm with the structure of Heterodyne-Fractional Fourier Transform （FRFT） is proposed. To reduce the computation of searching targets in a two-dimensional FRFT result, the heterodyne signal will be processed by FRFT at a specific order, after Radon-Ambiguity Transform （RAT） is applied to estimate the sweeping rate of the signal. Simulations proved that the algorithm can eliminate the coupling phenomenon of distance and velocity of LFMCW, and estimate targets＇ parameters accurately. The lake trial results show that the processing gain of LFMCW processed by the algorithm is 13 dB better than that of the LFM processed by matched filter. The research results indicate that the algorithm applied in LFMCW underwater detection is feasible and effective, and it can estimate targets＇ parameters accurately and obtain a good detection performance.
出处
《声学学报》
EI
CSCD
北大核心
2014年第2期163-169,共7页
Acta Acustica
基金
"十二五"预研项目(4010201010203)资助
