With the widely use of electronic equipments and the diversification of radar system in modern warfare, the electromagnetic environment becomes more and more complex and changeful. This has brought forward austere challenge to signal selection. How to select and analyze signal exactly from the complex environment and give out accurate tracing wave-gate is one of the most important missions in the anti radiation seeker system. Most traditional signal selecting methods by generating the tracing wave-gates by pre-setting signal parameters can't satisfy the real time requirement, so some gradually changing signal parameters such as phase difference and amplitude can't be used adequately. This paper mainly researched how to select signal with the time domain parameters and spatial parameters in the dense signal environment, and constructed a real time signal selection system, which improved the tracking accuracy greatly.Firstly, the theory of direction-finding method was introduced in this paper, demonstrating that the phase difference changes with direction-of-arrival of the signal. Secondly, the sequence searching algorithm, coherence checking and recursive estimation algorithm and signal elimination depending on their probability algorithm were discussed which educed the main basis of this system. The system integrated the TI Crop's high speed TMS320C6201B DSP and the ALTERA Crop's bulky FLEX10K30A as the key hardware. The filtering, samples-averaging, edge-aligning and width-adjusting, two-parameter-correlation filtering and delay circuits were designed in the FPGA and simulated with Quartus II software. The algorithms such as sequence searching algorithm, coherence checking and recursive estimation algorithm as well as FLASH program were also designed in C program and explained in detail.Finally, the paper summed up the problems in debugging and it also presented some solutions and some improvement ideas. |