Study Of Experimental System For Frequency Hopping Spread Spectrum Based On FPGA

Frequency hopping spread spectrum communication is a hot topic of international research. Since it has the advantage of strong anti-jamming ability, low probability of being intercepted, hidden signal and easy networking, it is widely used in military and civilian fields. According to different spread spectrum ways, it is divided into Direct Sequence Spread Spectrum(DSSS),Frequency Hopping Spread Spectrum(FHSS),Time Hopping Spread Spectrum(THSS),Pulse Linear Spread Spectrum and Mixed Mode, Direct Sequence Spread Spectrum and Frequency Hopping Spread Spectrum are the most typical and most frequently-used.This paper focuses the study on frequency-hopping spread spectrum communication experiment system, including system architecture, hardware design and software design. As the FPGA has the advantages of low-power, low cost, high reliability and short development period, it is widely used in the area of communication and electronic, so the core part of system is designed based on FPGA.This paper first analyzes the current development of frequency hopping communications. According to the theory of frequency hopping communication, the overall structure of experimental system is given, and the frequency hopping transmitter module, frequency hopping receiver module, synchronization and control system module design is completed. The frequency synthesizer using Direct Digital Synthesis (DDS), it has the advantage of high frequency resolution, wide frequency range, fast conversion rate and continuous phase, so it easily fulfill the requirement of hopping carrier. In order to observe the signal easily for students, the test point is set in the key part of each module. Experimental system used in the structure of common backplane and bus control mode, the function module also uses a unified structure, which make the system has the features of flexibility to mix, easy to upgrade, high participation for student, more experimental module. So the design and innovative experiment can be completed very well.In addition, MCU processor, LCD display, sixteen bits keyboard and RS232 interface is configured in the system which make it easily communicate with the PC machine. Hardware design uses ProtelDXP, software design uses language of VHDL and assembly language in microcontroller. VHDL program designed in Quartus II 7.2 simulation environment, part of the core program is tested in KANGXIN SOPC experimental box, functional and technical specifications meet the design requirement.