| Since the rapid development of the electro information technology and the new telecommunication service, and the continuing spread of the radio spectrum, the electromagnetic environment keeps worsening, especially the intersystem interference which has been a serious barrier that affect the daily run of the radio communication system. The mobile communication technology in the 21st century must solve several key EMC (electromagnetic compatibility) problems, so as to let the technology develop under a reasonable cadre, which means the EMC of various radio technologies should be taken into consideration, as well as the continuance development of EMC now and in the future. The research includes two parts - the intrasystem EMC and the intersystem EMC. The intersystem interference is to analyze the performance worsening caused by mutual interference and destroy in more than two systems. Through the analysis, the system can be improved effectively to ensure the high efficiency telecommunication transmission.In nowadays, since the rapid development of information technology, UVA (unmanned aerial vehicles) is a hotspot in today's world military force development. Its application range and field kept enlarging. It is predicted that the UCAV may become the new aerial weapon in the 21st century, and become the dominant aerial force. And it will play an irreplaceable role in the military application field. Moreover, besides the military field, the UAV also has an extensive application foreground in the civil field. Therefore, it is very important to confirm its reliable communication. CDMA (Code Division Multiple Access) is a new and mature mobile telecommunication technology which is based on the branch of digital technology -spread communication technology. The technology can meet the requirements of modern mobile communication, which are great capability, high quality, integrated services, soft handover, international roaming. This technology is considered the first choice of the 3rd generation mobile communication technology and has a wide foreground. Since the UAV is the aerial vehicles controlled by the terrestrial station, its frequency spectrum is very wide (from DC to band L), which results in worse operation environment. Thus, it must be interference by signals from various bands, which definitely includes the interference from CDMA signal. The intersystem interference BER is easily analyzed through the simulation, which has great signification in research and solving problems in the real system.In this paper, the MATLAB/SIMULINK is used to build the UAV system based on DSS technology and the UAV system based on hopping frequency technology. In the real simulation module, the DSS and BPSK code is used to simulate the real CDMA signal. The simulation analyzes the interference from CDMA signals to DSS UAV signals and the interference from CDMA signals to hoping frequency UAV signals in the AWGN condition. Moreover, the paper analyzes the results of the simulation and offers the conclusion and improvement suggestion. |
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