The Research And Implementation Of Multi-target Gradient Tracking Algorithm Based On DBF-CDMA

With the development of aerospace undertaking in our country and the need ofinformation-based national defense construction, the probability of multiple aircraftappearing in one airspace is becoming more and more big which requires the groundstation have the ability of tracking and controlling multiple aircraft at the same time.Because existing ground control stations in our country is made of a large high gainnarrow beam antenna to capture vehicle tracking, this is difficult for large antenna ofguidance and the servo system to jump between multiple targets tracking is difficult toachieve in a short period of time. Digital Beam Forming (Digital Beam Forming, DBF)technology can solve this problem well. it is a kind of soft antenna array trackingtechnology. Output signals make summation in the digital domain after A/Dtransformation, which makes the signal gain maximum in the desired direction. It canform the multiple beam for multiple target tracking in the case of no loss ofsignal-to-noise ratio. This paper proposes a gradient tracking scheme based on DBFcombined with CORDIC and CDMA technology and do some research mainly from thefollowing several aspects.Firstly, the measurement and control system development history and researchstatus at home and abroad is introduced, and this raises the measurement and controlscheme based on DBF-CDMA; After that the basic theory of antenna array and arrayantenna is introduced in detail; Then the relevant theories of digital beamformingtechnology and CORDIC algorithm is introduced in detail; And the the overall diagramof aircraft measurement and control system is given, and the related theory of CDMAspread spectrum technology is also be discussed, this paper introduces the principle ofdigital matched filter and its application in pseudo code capture,and then the necessarysimulation is made using Matlab software; Finally in this paper, puts forward a newFPGA implementation method using CORDIC algorithm and digital beam formingtechnology and the circuit principle diagram is given, The circuit diagram is designedand the programming is finished by using Verilog.The simulation result by using ISEand Modelsim software is also carried out. The simulation proves that this method iscorrect and effective.