Simulation And Research Of GMSK Frequency Hopping Communication System

Frequency-Hopping(FH) is a novel spread spectrum communication technique which develops very fast in military field due to its Low Probability of Intercept Detection of properties and immunity against interferences , The extensive application of HF/VHF (high frequency/vey high frequency)frequency-hopping radio in military has greatly enhanced ability of military equipment against jamming and interception and ensure the safety and validity of chain of military command.At present, many military information had developed from simple commanding order to radar detecting data,computer calculating result,high-speed image fax and so on ,Modern FH communication system need transmit a mass of data, traditional modulation are no longer suitable for high–speed data transmitting in FH system due to low spectrum efficiency, Therefore it has a practical significance to develop some fit methods of modulation with high spectrum efficiency of FH communication system.In all kinds of modulation, with the advantage of good spectrum utilization and power efficiency as well as noncoherent demodulation can be employed. GMSK(Gaussian Minimum Shift Keying)has been widely applied in the wireless system .It will be introduced for FH to implement high-speed data transmitting in this paper. Firstly, base on some digital modulation techniques used in FH system, main research is made on the principle, the method of generation and demodulation, characteristic of GMSK signal ,Secondly, according to the feature of FH channel, Finally, take full use of Simulink module in MATLAB to build computer simulation model, The simulation results show that, GMSK frequency hopping systems in the absence of errors control of the transmission can get better results,it is feasible to introduce the GMSK into the FH communication.