The decoding system of semi-active laser guidance based on FPGA

Abstract

In this paper,we describe a new design of semi-active laser guided decoding system based on FPGA.The system is designed to receive the echo pulse through a 4-qundrant laser sensor and process the digital laser pulses through analogdigital conversion,which are some fixed interval encoding signal reflected from the target.The decoding system improve the adjustment accuracy of the laser seeker,which reach 0.1us about 50 times in theory compared to current technology. State machine is used to address complicated laser signal,including how to hand of the identification and trapping of the correct laser pulses,how to hand of a state of anti-jamming,how to hand of capturing the laser pulses again after signal missing.And a real-time gate signal is adopted to enhance the ability of anti-interference [1] . Processed signal is used to monitor and control,the processed result is transmitted to a electric actuator and subsequently be sent to laser seeker as a guidance signal or to a PC to simulate and monitor or to be stored in Flash that can extract whenever needed. The whole performance of the system is oprated in laboratory and decoding model is simulated with Modelsim module in detail.The testing results show that the design can reduce the span of decoding time effectively,identify and track the echo pulses from target correctly even to the missed codes or interferential codes.The feasible technique wins the time for laser guidance,and has some theoretical and military value.