光学 精密工程, 2014, 22 (11): 3122, 网络出版: 2014-12-08
低截获概率雷达信号检测方法的优化及应用
Optimization and application of LPI radar signal detection method
雷达信号 信号检测 循环谱 低截获概率 傅里叶变换(FFT)累积算法 radar signal signal detection cyclic spectrum Low-Probability-of-Intercept(LPI) Fast Fourier Transform(FFT) algorithm accumulation
摘要
针对利用循环谱理论检测低截获概率(LPI)雷达信号存在计算量大的问题, 提出了一种优化的快速傅里叶变换(FFT)累积算法来更新信号处理设备的软件程序。分析了原软件中信号处理的过程, 提出了采用并行流水型结构的优化方法;利用前一个滑动窗口内采样信号的FFT, 推导出下一时刻采样信号序列的FFT;通过减少重复采样点, 减少计算量。然后, 利用循环谱检测中4个象限的循环谱的对称性, 减少计算象限数, 并采用一维搜索进行峰值检测, 从而进一步减少计算量。理论推导显示, 改进方法减少了计算复杂度和计算量。最后, 利用提出的方法对常用的线性调频(LFM)和二进制相移键控(BPSK)信号进行了分析。结果表明, 在相同条件下, 利用改进的算法及一维搜索, 计算时间可缩短为原算法的1/25左右。另外, 算法改进后检测信号的幅度值仅减小了不到10%, 不影响后续处理对循环谱参数的估计。
Abstract
As Low-Probability-of-Intercept (LPI) signal detection algorithm based on cyclic spectrum theory has a very large amounts of calculation, this paper proposes an optimized algorithm, Fast Fourier Transform(FFT) accumulation, to update the software program. The signal processing of the original software is analyzed, and the new algorithm based on a parallel signal processing structure is proposed. The new algorithm derives the next FFT sampling signal sequence by the previous FFT sampling signal sequence in a sliding window. By reducing the repeated sampling points, the new algorithm reduces the amount of calculation. In view of the symmetry of the four quadrant of the cyclic spectrum, the quadrant to be calculated is decreased. Moreover, by using one-dimensional search peak detection, the amount of calculation is reduced further. Theoretical derivation demonstrates that the complexity and calculation amounts of the proposed algorithm are reduced obviously. Finally, through verifying the Linear Frequency Modulation (LFM) and Binary Phase Shift Keying(BPSK) signals, it indicates that the calculation time is reduced to about 1/25 that of the original algorithm. In addition, the amplitude values of signals in the optimized algorithm are reduced less than 10%, which not affects the estimation of parameter of a cyclic spectrum.
李娜, 王珂, 李保珠. 低截获概率雷达信号检测方法的优化及应用[J]. 光学 精密工程, 2014, 22(11): 3122. LI Na, WANG Ke, LI Bao-zhu. Optimization and application of LPI radar signal detection method[J]. Optics and Precision Engineering, 2014, 22(11): 3122.