Research On Key Techniques Of Frequency-Hopping Communication System

Spread-spectrum technique is a kind of technology of information transmission. It uses the pseudorandom code to transmit signal. The technique has been widely used to prevent and reduce interference in the field of tactics communications.Frequency hopping technology is widely used not only in military communication, but also in civil mobile communication, such as Home RF, GSM and Bluetooth etc. The frequency hopping communication has several key techniques in the frequency hopping communication, such as frequency hopping sequences design, frequency hopping synthesizer design, frequency hopping synchronization and networking.The paper mainly introduces FH communication principle, structure, mathematic model and related parameters. Synthesizer design, synchronization performances and anti-jamming are theoretically analyzed and simulated study.Firstly, PLL synthesizer is discussed. From the simulation research, we have found this fast PLL synthesizer had several advantages, such as high stable frequency and high anti-jamming phase noise performance.Besides, a widewidth frequency synthesizer is designed with the scope 500MHz~4GHz. Its frequency step is 200 KHz and the output power is 0dBm. It has several advantages including good phase noise parameter. In all, it is quite suitable for the frequency hopping communication system.Secondly, we have studied several methods of synchronization. And a model of FH synchronization system is built on the Matlab/Simulink software platform. In this section, I want to introduce the most key technique about hopping synchronization,such as waiting type self synchronization method. Of course, I have realized the desired results.Lastly, the paper analyses the reason why FH communication system can resist typical jamming from the theoretical point. After that, bit-error-rate (BER) calculations of FH/BFSK system under jamming conditions are presented, This simulation model of FH communication system is built on the Matlab/Simulink software platform, and we attained each BER-JSR curve figures in the jamming model.