A. S. Gribanov – Ph.D. (Eng.), Associate Professor, MAI, Senior Researcher, JSC «MNIRTI». E-mail: firstname.lastname@example.org
V. E. Eremina – Engineer, JSC «MNIRTI». E-mail: email@example.com
The paper presents an analysis of methods of signal transmitting on tropospheric communication links in a multipath environment. One of such method is method with frequency adaptation developed by V. Serov, during which implementation is performed periodically channel sensing and the selection optimal frequency for the transmission. In spite of this method solves the problem of communication over the horizon, it has two disadvantages: time and frequency constraints.
The method of coherent addition is proposed as an alternative to the method with frequency adaptation. The essence of proposed method is the in-phase addition of each beam of multipath signal in the receiver. The method of coherent addition involves the utilization linear frequency modulated (CHIRP) signals. According to the received chirp signal frequency the phase of each beam is determined, whereby the corresponding delay introduced. By the proposed solution it can be obtained energy gain up to 6 dB in comparison with method with frequency adaptation.