Pseudo-code Fm Difference Frequency Signal Processing Technology

The pseudo code frequency modulation signal processing technology uses the binary digital baseband signal to modulate the carrier signal, different Numbers correspond to different frequency of the carrier. In the sending end, the pseudo code generator choose different emission signal frequency to transmit signal "1" and "0". At the receive end, through the coherent demodulation the system set the different frequency carrier signal to corresponding digital baseband signal. We can get the distance to the selected target information through comparing two groups of digital signal delay. The system contains both the characteristic of the pseudo code system wireless electric target detector system and frequency hopping communication system. It has very wide signal bandwidth and great signal processing gain. It has a lot of advantages in the anti-jamming, resistance to monitoring and anti reconnaissance circumstance. It is a very promising radio distance system, which caused the domestic and foreign wide attention and research.This thesis analyze anti-interference ability of the system through correlation reception and related processing gain of the pseudo code frequency modulation signal processing technology.Secondly it introduces the pseudo code frequency modulation signal processing technology principle, and do the mathematical deduction of the system from the distance and speed aspect, then the system parameters are determined. And then according to the mathematical theory the Simulink simulation model is established,and obtain the simulation results and theoretical derivation consistent conclusions. In the basis of the mathematical deduction and Simulink simulation model, hardware circuit system is designed, it contains the power splitters, envelope detector, AD sampling circuit, the layout is drawed and the circuit is debugged with good result. Finally, based on FPGA algorithm software programming. Respectively introduces AD sampling control, FFT nuclear use, echo pseudo code capture, and digital correlation processing module. Through the debugging the correctness of the software algorithm is verified. In addition some software modules experiment is done, which obtains satisfactory results. It meets the requirements of principle prototype and achieves the desired function.