Research And Implementation Of Airborne Passive Robust STAP And Hardware Acceleration Method Based On C-band High Speed Direct Sequence Communication Signal

Tactical data link(TDL)is the core basis of systematic confrontation in modern warfare,and it exists widely in the battlefield.High-speed direct sequence(DS)and frequency hopping are two typical anti-jamming techniques.Airborne passive detection(APD),which uses high-speed direct spread tactical data link signals as the source of illumination,has the advantages of high resolution,concealment,and no active radiation.In this paper,the airborne external source detection research is carried out for the C-band high-speed direct spread communication signal.However,the traditional Space-time adaptive processing(STAP)technology based on uniform sample data suffers from the deterioration of clutter suppression performance caused by sharp carrier and code doppler broadening and non-uniform distribution of clutter intensity.To this end,this paper proposes an airborne external source robust STAP method based on C-band high-speed direct spread tactical communication signals,and carries out hardware acceleration design and experimental verification,as follows:First of all,this paper establishes the frame structure model of the C-band high-speed direct-spread signal,the geometric model of airborne external source detection,and the space-time model of clutter,and reveals the sharp broadening and non-uniform distribution of the clutter carrier and code doppler.The relationship between it and the performance and complexity of the traditional STAP method is analyzed.In order to solve the high complexity problem caused by clutter doppler broadening,a beam doppler domain dimensionality reduction method based on sparse recovery(SR)is adopted.In order to ensure the update speed of weights,this paper uses systolic array(SA)to design the system as a multi-stage pipeline structure parallel computing to achieve the purpose of hardware acceleration.Then,aiming at the STAP performance loss caused by channel amplitude and phase errors and clutter distance walking,this paper proposes a channel correction method based on direct communication signals and a code doppler compensation method in the beam doppler domain;for the distance dependence of clutter,using adaptive angle doppler compensation(A~2DC)is used for compensation.The simulation results show that compared with conventional processing,the improved robust STAP method in this paper can still obtain a good improvement factor(IF)curve when the clutter carrier and code doppler are sharply broadened and strongly non-uniform distribution,so it can more effective suppression of clutter,improving the robustness of the system.Finally,this paper establishes the hardware realization system model of airborne exogenous space-time adaptive processing.The hardware acceleration design and experimental verification of each key sub-module in the system are carried out.The experimental results show that the system built in this paper has obtained a good output signal-to-clutter-plus-noise ratio(SCNR),which meets the system’s requirements for clutter suppression performance and weight update speed.