高斯噪声下伪码-线性调频复合信号参数提取方法

针对目前雷达信号参数估计算法在某种环境中性能急剧下降,甚至失效的问题,提出一种基于多相滤波器组和高阶累积量联合处理的伪码-线性调频复合信号参数估计算法.该算法首先利用多相滤波器组实现信号在频域上快速均匀划分,然后对输出的每个子带信号进行三阶累积量对角切片的短时估计,有效抑制高斯噪声的干扰,并经过包络检波后得到复合信号完整的时频矩阵,最后通过时频图像的Radon变换和频率曲线的提取实现信号伪码数目、码元宽度、调频斜率、信号载频、带宽以及起止频率的提取.仿真结果表明,该方法在信噪比大于-11 dB时的估计精度较高.

Parameter extraction method of radar signal Combined PRBC and LFM with Gaussian noise

The extensive application of low probability of intercept (LPI) radars caused most of the interception of radar signals with low SNR. The performance of the common parameter estimation algorithms of radar signals will be inevitably corrupted in low SNR. To estimate the parameters of radar signals combined pseudo-random binary phase code (PRBC) and linear frequency modulation (LFM) in low SNR, a novel method was proposed based on the poly-phase filter bank and high-order cumulant.Firstly,it realizes the uniformity signals in the frequency domain rapidly by the poly-phase filter bank.Then the Gaussian noise can be suppressed by using the short-time estimate of the third-order cumulant on each narrow frequency band.The estimation of the whole time-frequency matrixes can be obtained with envelope detection.Finally,the chirp rate, code-width and code-length of compound signal can be estimated by Radon transform of the Time-Frequency images. At the same time,the carrier frequency, band width, start-stop frequency can be estimated by extract the frequency curves. Simulation results show that all parameters of the compound signal can be evaluated precisely when SNR is more than -11dB.