| With the development of military informationization,our army is equipped with a large number of DS/FH radio stations,which provide guarantee for our army’s secure communication in the information battlefield.In order to meet the basic level technical state inspection,relay technology state examination level cruise when repairing and base level emergency repair to the demand of the rapid detection of DS/FH radio,a portable,reliable,easy to use and integrated DS/FH signal source is needed to provide an exciting signal for radio testing.Based on the requirements of the test index of an airborne DS/FH system stations,a DS/FH Signal Transmission System implementation scheme based on FPGA is proposed in this paper.On the basis of introducing the basic principle and mathematical model of the diffuser frequency system,the realization block diagram of its transmission system is given.The key technologies in the transmission system are studied,and the principle and performance of each key module of the sending system are analyzed by means of auxiliary tools.In particular,the algorithm for generating wide spaced frequency hopping sequences is studied.Aiming at problems of the limitation of the range of frequency point spacing and the omission of the frequency pair satisfying the wide interval in the traditional dual sub-band method,an improved dual sub-band method is proposed to improve the processing of dual sub-band method.Matlab software is used for simulation verification.The simulation results show that the improved algorithm improves the anti-jamming performance of the wide spaced frequency hopping sequence.Then,the hardware implementation architecture of the DS/FH system is determined,and the system is divided into several important modules according to the system architecture in the FPGA hierarchy.After using the Quartus software development tools design,programming,debugging and validation of the various modules of the system,and making use of the third party Modelsim simulation software to observe some important modules of sine signal output simulation diagram,completed the sending system software design.The main modules involved include data convolutional coding module,data interleaved coding module,data,π/4-DQPSK modulation module,frequency hopping sequence generation module and AD9915 control module.In the end,the hardware circuit design of the DS/FH system was completed,and the PCB board production was completed and verified. |
