Research And Implementation On Diferential Frequency Hopping Transition Function

The differential frequency hopping system is based on the technique of digital signal processing. By adopting many advanced technique such as Differential Frequency Hopping(DFH), asynchronous frequency hopping and broad band receiving, it can implement the frequency hopping with broad band and high speed in short wave band, and extremely improve the anti-interference ability of tracing and multi-path, and the data rates at the same. So the research on the DFH system and the novelty techniques is of significance.On the basis of the analysis and discuss about the DFH technique and system, the research on the DFH G function algorithm and the implementation technique of the DFH system's transmitting part are all developed in this paper. The simulation module of the system is established using the SIMULINK simulator of MATLAB. According to the concept and building fundament of DFH G function, a testing method is showed to estimate the performance of G function. A DFH G function algorithm based on chaotic mapping is proposed, and the randomicity and uniformity tests of its code sequence is done. An approach to realize finite precision chaotic mapping via perturbation of m-sequences is adopted. The transmit part of the DFH system is designed and implemented. In order to verify the validity of the transmit part, experimental detect system based on the PC bus collecting card is designed according to the principle of the receiving part of the DFH system. Based on the idea of visual programming, Delphi5 is used to develop the data analysis and display software.Experimental results show that the frequency hopping code sequence generated by the DFH G function based on the chaotic mapping presented in this paper has better randomicity and uniformity, and the hardware circuit of the transmit part can generate the DFH codes and high speed frequency hopping signals. It is valuable for the research of CHESS radio design in future.