Design And Implementation Of The Shortwave FH Communication System Based On Software Radio Technologies

The shortwave FH communication system has both of the advantages of the short wave communication and the frequency hopping communication. For the long-distance transmission of the shortwave communication and the strong anti-interference of the FH communication,the shortwave FH communication system has been widely applied in military and civilian ways. But the traditional shortwave FH communication system is too strong dependence on hardware equipment, upgrading product need high cost and the poor flexibility. This article studies the shortwave FH communication system has the advantages of the softwave radio technologies,it can been upgraded by programming and supports the multiple formats. The part of signal processing is not high requirements for hardware platform,it can greatly improve the performance of FH communication system.This paper is based on the Universal Software Radio Platform(USRP) to realize the shortwave HF technologies. It can make full use of the advantages of software radio technologies, such as the flexibility, the reconfiguration and so on, to build a flexible shortwave FH platform. Compared with the traditional shortwave FH system, the shortwave FH system based on software radio technology has more flexibility, for the most part signal processing is conducted on the PC, and then it also can reduce some inevitable error that processing in the hardware. It don’t need too high to the requirement of hardware performance, greatly reduce the hardware cost.In this paper, using the software radio general platform USRP- N210 as the signal transceiver, the signals are analyzed on the signal processing softwave platform of GNURadio. Because of the Guassian Minimum Shift Keying(GMSK) compared with the other modulation, it has the advantages of compact spectrum, good BER performance. Therefore, this article take GMSK technology for modulation, it through the python and c + + mixed programming to realize the GMSK modulation technology on the softwave platform of GNURadio, generating the universal gnuradio signal processing platform module, and then importing the software environment, so we can use the module to modulate the signal. the shortwave FH signal spectrum that This paper studies range from 3 MHZ to 30 MHZ, the spectrum of this range of short-wave can be reflected or refracted by ionosphere and then return to the earth, to achieve the purpose of long distance communication. This range frequencies of short-wave communication is mainly applied to point communication, military communication and broadcasting.