Study Of The Communication System Based On OFDM Cooperative Communication In Sand-Dust Storm Environment

During the wireless communications, the main factors that influenced the quality of wireless communication is the complexity of the transmission environment and multipath fading of wireless signals. The transmission environment in the sand-dust storm is more complex than that in the urban environment. There are many factors that can influence the transmission of electromagnetic wave, such as the loss of signal transmission in the sandstorm channel, the attenuation that caused by the water content and visibility of the sandstorm, the polarization effect of dust particles influence on electromagnetic waves, the scattering effect of dust particles, and so on.There are many factors that influence the propagation of electromagnetic wave in the sand-storm environment, the scattering effects of dust particle is one of the major factors, so this paper focuses on the dust particles scattering function. The scattering of dust particles inevitably brings the multipath transmission of the signal, multipath propagation will bring the multipath fading of the signal. Therefore, multipath fading will become one of the main factors that affect the quality of signal transmission. Cooperative communication technology and OFDM technology has good anti-fading ability, so combining the two technologies in the communication system of dust storms, which can guarantee the signal transmission timely and correctly.This paper is based on the characteristics of cooperative communication and sand-dust storm environment. First of all, it makes some introduce about cooperative communication,and some key technologies of cooperative communication is discussed. In the discussion of cooperative communication key technologies:diversity combining technology is discussed, then the three main diversity combining technology is discussed and compared; Then the selection of relay node and power allocation in cooperative communication are introduced. In the comparison of three diversity combining ways, it can come to the conclusion that using diversity combining technology can improve system performance. Because of its good performance and easy realization, EGC mode is widely used in the cooperative communication system.Next, in this paper, the cooperative communication model and the impact of electromagnetic wave propagation in the sand-dust environment are done research and analysis. In the research of cooperative communication model and performance, it mainly aimed at Amplify-and-Forward(AF) modle and Decode-and-Forward(DF) modle, then it can build the modles and come to the conclusion of AF and DF. It is the conclusion:when using collaborative mode to communicate, it can effectively improve the system performance, and it is the low-order modulation method that can help the system keep in a good situation.Finally, according to the influence that electromagnetic wave spread in the sand-dust storm environment, combining OFDM technology and cooperative communication technology that can overcome the influence caused by dust particle scattering in sand-dust storm. The research about sandstorm collaborative communication system is from three aspects:the influence that sandstorm channel effects on OFDM cooperative system; the influence that the quality of cooperative communication channel between source node and relay node effects on OFDM cooperative system; The node’s location of the relay impacts on cooperative communication system.