Study On Radar Signal Sorting Method Under Multipath Effect

In modem electronic reconnaissance,the high pulse density of radiator,various modulation modes and multiple jam signals make complex electromagnetic environment more complex.Especially the multi-path signals formed by different paths echoes when tracking targets is a typical,which poses a great challenge to the existing radar signal sorting methods.Multipath signals are difficult to be distinguished by traditional signal sorting methods because of the similar parameter characteristics among them.In view of the above problem,according to the law and basic principle of the signal polarization state after reflection,the polarization parameter of the signal is selected as another dimension of freedom of signal sorting algorithm,and can solve the problem caused by multipath added-batch interference.Firstly,the multipath signal interference in the sorting electromagnetic environment is explained and the mathematical model and its influence are discussed.The disadvantages of multipath interference suppression methods in the front signal processing are studied,which provides a theoretical basis for subsequent research.Secondly,a sorting method named as SONN-POLAR aiming at the sorting problem of unknown radiation source with multipath added-batch signals is proposed.The method uses the SONN algorithm based on multi-parameter as the main sorting method,and then multipath batch signals are seperated by the method of polarization amplitude joint observation.Finally,a semi-physical simulation platform for radar signal sorting under multipath effect is designed.The platform generates a multipath and added-batch signals by the radar IF digital simulator to simulate the real electromagnetic environment,and transmits the pulse descriptor word to the PC for main signal sorting to complete the sorting process.The test results show that the SONN-POLAR sorting method can effectively solve the radar signal sorting problem under multipath effect on the condition of semi-physical simulation and has high sorting reliability.