Pseudo-code Phase Modulation Sawtooth Linear Fm Composite Fuze Signal Processing Technology

Because weapons become more faster and the complex electromagnetism environment in the future war. modern fuse have to possess strong anti-jamming capability and the ability of accurate distance-determination, identify the target when in the condition of big Doppler signal. It is the direction by using complex modulations in fuse.In this thesis, the operating principle of complex modulation fuse was discussed in detail. Then the process of modulation, demodulation and signal processing was simulated in Matlab. We can effectively weaken the impact of Doppler signal on PN correlation by selecting the appropriate parameters. Through spectral analysis of complex modulation fuse, the ability of anti-jamming was discussed in this thesis. Compared to the single modulation fuse, the complex modulation fuse has excellent ability in anti-jamming. While discussing the complex modulation fuse, the beat frequency of saw-tooth wave linear frequency modulation and the sensitivity of Doppler signal in PN code phase modulation were discussed and simulated by Matlab. In this thesis. PN signal was acquired through signal processing. The PN signal was used to correlate with another pseudorandom code, through this to determinate the distance. In addition, the digital correlation based on the software of Xilinx and the hardware of XC2S100E-6-TQ144 FPGA is designed. Then under different distances, the digital correlation was carried out by means of Modelsim. The demand to output high level when at particular distance was achieved; meanwhile, some experiences in the process of designing and implementing hardware which is based on FPGA are summarized. At last, the design and simulation of low pass filter, small signal magnify, Hysteresis Comparator and large-signal blockage circuits are completed.