Costas编码跳频信号多普勒容限及其在多声源宽带正交检测中的应用

针对Costas信号的传统宽带匹配滤波因拷贝信号生成过程复杂而带来的计算复杂度高的问题,给出了一种通过计算宽带回波与窄带近似回波的互相关度进而得到Costas信号多普勒容限的数值计算方法,并提出利用容限值对预测目标多普勒范围进行分段窄带近似处理,从而避免了大量的时域伸缩变换,简化了拷贝信号的生成复杂度,提高了宽带匹配滤波的处理效率。随后,将这种方法扩展应用到多声源多目标的回波检测中,利用Costas信号的正交性及多普勒容限值,设计了一种宽带正交匹配检测器,大大提高了多目标声探测的效率。实验仿真和分析证明了多普勒容限求取方法的正确性及其应用于宽带正交匹配检测的有效性。 

On Doppler tolerance of Costas-coded stepped-frequency signal and its application to wideband orthogonal detection for multiple sound sources

We consider the problem of reducing the computation complexity in wideband matched filter, which is arose from the calculation of the time compressed replicas. To solve this problem, the Doppler tolerance of Costas waveform is derived by calculating the correlation loss of the time-compressed echo and the frequency translated version of the transmitted signal first. Then a narrowband approximation method for wideband detection is proposed to partition the anticipated target Doppler range into several segments. As a result, the generation of replicas is much simpler than the conventional wideband ones and the wideband matched filter processing is more efficient. At last, we extend this method to the application to wideband echo detection in the context of multiple sources and targets. Based on the Costas Doppler tolerance and its orthogonality, a wideband orthogonal detector is designed to increase the detection efficiency. Simulation results prove the validity of the Doppler tolerance calculation and its effectiveness in wideband orthogonal detection.