Journal of Xidian University ›› 2023, Vol. 50 ›› Issue (6): 21-33.doi: 10.19665/j.issn1001-2400.20231003

• Special Issue on Elctromagnetic Space Security • Previous Articles     Next Articles

Fast algorithm for intelligent optimization of the cross ambiguity function of passive radar

CHE Jibin(),WANG Changlong(),JIA Yan(),REN Zizheng(),LIU Chunheng(),ZHOU Feng()   

  1. Key Ministry of Education Laboratory of Electronic Information Countermeasure and Simulation Technology,Xidian University,Xi’an,710071,China
  • Received:2023-02-02 Online:2023-12-20 Published:2024-01-22

Abstract:

The passive radar system realizes the target detection by receiving the direct wave signal from the emitter and the target echo signal.The cross ambiguity function is an important means to improve the coherent accumulation of the echo signal.However,the echo signal received by the passive radar is very weak,so it is necessary to increase the accumulation time to improve the estimation accuracy.When the target speed is fast,the frequency search range increases.In order to achieve a range of target detection requirements and take into account the real-time performance of data processing,it is of great significance to study the fast calculation method of the cross ambiguity function,and due to the objective requirements of long-time accumulation and large-scale time-frequency search,the computation of the cross ambiguity function is huge,which makes it difficult for the traditional accelerated calculation method based on ergodic search to meet the real-time requirements of system processing.In order to improve the efficiency of cross ambiguity function optimization,a time-frequency difference calculation method based on multi-group feature optimization is proposed in this paper.By deeply analyzing the characteristics of typical digital TV signals,a two-stage cross ambiguity intelligent optimization fast calculation method based on target characteristics is designed in the framework of particle swarm optimization theory.By designing an effective search strategy,this method introduces the multi-population iteration mechanism and shrinkage factor,which avoids the disadvantages of the traditional method of redundant computation.On the premise of ensuring the calculation accuracy,the time-frequency point calculation is greatly reduced,and the search efficiency of cross ambiguity function is improved.

Key words: passive radar, ambiguity function, particle swarm optimization, target detection

CLC Number: 

  • TN959.16