一种基于运动补偿的高动态微弱直扩信号捕获算法

针对高动态长时间积累情况下直扩信号能量无法有效积累的问题，提出了一种基于运动补偿的二倍分组块补零（Double Block Zero Padding，DBZP）算法。首先利用Keystone变换对输入信号与本地伪码在频域相乘后的结果进行处理，消除伪码自相关峰走动；再利用分段解线调技术同时补偿掉多普勒扩展和伪码自相关峰弯曲；最后对信号进行相干积累。仿真结果表明，基于运动补偿的DBZP算法能有效地消除动态的影响，大幅减小积累损耗，进而提升捕获灵敏度。该算法能广泛应用于基于直扩信号的高动态微弱目标捕获。

A Weak DSSS Signal Acquisition Algorithm Based on Motion Compensation under High Dynamic Scenarios

The energy of DSSS signal cannot be accumulated effectively under the condition of long term integration and high dynamic scenarios, to solve this problem, a Double Block Zero Padding (DBZP) based motion compensation algorithm is proposed. The Keystone transform is used to process the multiplication of the input data and the local PN code in the frequency domain, and the range walk of PN code autocorrelation peak is eliminated. Then segmentation dechirp is used to make compensation for Doppler expansion and PN code autocorrelation peak curvature simultaneously. Finally, signal is coherently accumulated. Simulation results show that the DBZP based motion compensation algorithm can eliminate dynamic effect effectively, significantly reduce the accumulated loss, and thereby improve the acquisition sensitivity. The algorithm can be widely used in high dynamic weak target acquisition based on DSSS signal.