Research On Technologies Of Diversity And Combining Of COFDM-FM Signals In Troposcatter Communications

In this paper, the characters of COFDM modulation technology and the characters of troposcatter were given firstly, and a modulation scheme of COFDM-FM was given also. The results of the analyzing were that COFDM-FM could meet the requests of resisting multipaths and high-speed transmission of troposcatter communication system. To improving the performances of resisting multipaths further, a feasible scheme of equal-gain combining was adopted. The key technologies of this scheme were researched deeply and a technique of removing the differences of phases among branches, and then as a result, the performance of the communication system will be promoted sharply. At last, the actualization of this combining scheme was discussed deeply. The results of analyzing, simulating and experiment indicate that the method of combining was effective. At the last of this paper, the detailed parameters of three kinds of foreign armies" equipment for troposcatter communication were given.