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.%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 is proposed based on the poly-phase filter bank and high-order cumulant. Firstly, it realizes rapid uniform-tivision of signals in the frequency domain 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 matrices can be obtained with envelope detection. Finally, the chirp rate, the code-width and the code-length of comp-site signal can be estimated by Radon transform of time-frequency images. At the same time, the carrier frequency, the band width, the start-stop frequency can also be estimated by extracting the frequency curves. Simulation results show that all parameters of the compsite signal can be precisely evaluated when SNR is more than -11 dB.
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