Research On High-Performance FH Sequences For Adaptive Frequency Hopping Communications And FPGA Implementation

Adaptive Frequency Hopping (AFH) is a type of FH communication with adaptive frequency control. By link quality analysis (LQA), AFH can continuously optimize the FH frequency hopset, to ensure the communication performances over frequencies without interference, thereby improving the quantity of the received signal. Compared with conventional FH communications, AFH has higher complicity of anti-interference and transmitting efficiency. Considering the dynamic change of hopset in the process of communication, research and design of pseudo-random sequences applied to AFH has been become one of the most important technologies to realize and improve the AFH scheme.In this paper, the basic principles and characters of AFH are introduced, and some sequences commonly used in FH are presented. Based on block cipher FH sequences, we propose a generation method of AFH sequence. Through pseudo-random mapping, this method can generate sequences of arbitrary hopset size. The design rules of this kind of method are obtained after deeply study and derivation, the good performance of the method is also proved theoretically. Simulations results and numeric analysis show that the AFH sequences produced by the proposed method have better comprehensive performance than existing sequences. Efficiently implemented in field programmable gate array (FPGA) by means of VHSIC hardware description language (VHDL), the proposed method has been applied to practical FH communication system as an independent function module.