Synchronization Scheme Design Of Frequency Hopping Communication System And Its FPGA Implementation

The requirements for confidentiality of military tactical missile data during wireless transmission are relatively high,and their communication methods should have strong anti-interference and anti-interception capabilities.Frequency hopping communication system has good confidentiality,anti-jamming and anti-interception ability,so the project uses frequency hopping communication as the wireless transmission of military tactical missile data,and synchronization technology is one of the key technologies in frequency hopping communication.This dissertation based on all kinds of indicators require of the subject design a synchronization program of frequency hopping communication system,which is realized by FPGA.After reading the indicators of the military tactical missile communication in the subject,this dissertation designs a set of frequency hopping synchronization including frame synchronization,bit synchronization and frequency hopping pattern synchronization based on the clock synchronization and non-Doppler frequency deviation of the sender and receiver in the communication process.This synchronization scheme is simple in structure and meets the technical specifications of the military tactical missile communication system.Among them,in order to improve the accuracy of frame synchronization,it is divided into rough detection and precise positioning in the scheme design.First,the energy detection method is used to realize the coarse synchronization of each frame of data.The sliding window energy accumulation operation using delay and accumulation operation,the method is simple and feasible and reduces resource consumption.Then,based on the bit synchronization,use state machine thinking to realize precise synchronization of frame synchronization sequences on symbol data.In the frame precise synchronization hardware implementation scheme design,the search state is set to continuously search the frame synchronization sequence until the frame synchronization is successful.This design method avoids missing detection of the frame synchronization sequence and improves the tactical missile communication quality.Bit synchronization is mainly to ensure the timing synchronization symbols,using digital phase-locked method,which extracts the bit synchronization signal with high accuracy and small error.Frequency hopping pattern synchronization achieve carrier frequency and hopping time synchronization.In order to enhance the anti-interference ability of the communication process,frequency hopping pattern synchronization use matched filter synchronization method to achieve frequency hopping pattern synchronization,and the establishment of synchronization time is short.In the design of synchronization program about this dissertation,carry on FPGA implementation of the frame synchronization,bit synchronization and frequency hopping pattern module synchronization scheme.Using the Verilog HDL hardware description language,a top-down approach to Xilinx ISE 14.7 software is used to realize the entire frequency hopping synchronization system.Then,use Mentor's ModelSim SE software for simulation.By analyzing the simulation results,the design of the synchronization scheme achieves the expected effect.Synchronization can be established in a short period of time and has the advantages of simple structure and so on.Finally,the baseband system is added for hardware testing.The result meets the requirements of the project index,and has certain application value and reference value.