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.