Background. Modem equipment of tropospheric communication lines is an important component of modern means of telecommunication. The theoretical and practical aspects of choosing a preferred embodiment of modem equipment, taking into account the aggregate indicators of quality. Objective. Presentation features the construction of modem equipment of the tropospheric stations of new generation that can provide high data transfer rates with guaranteed quality of service in complex stationary and

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... -stationary noise inherent in tropospheric channels. Methods. This goal is achieved by using new technical and architectural solutions to build a modem equipment, spectrally efficient modulation types and coding algorithms of effective adaptation to changing operating conditions. Feasibility of the proposed approaches to the construction of the modem hardware is fulfilled on a prototype of the equipment based on the HSMC ARRadio Daughter Card debugging modules. Results. The features of constructing of modem equipment of troposcatter stations with high data transfer rate are provided. To reach the limiting parameters of such stations proposed in the application of modem equipment of new technical and architectural solutions, spectrally efficient modulation types (OFDM plus linear modulation) and error-correcting coding, efficient algorithms of adaptation to changing conditions of work, the SDR technology, frame structures of physical layer. The variants of the configuration of modem equipment in relation to the modes of operation of compact troposcatter station. Conclusions. Ways of improving modem performance to improve the efficiency of modern compact troposcatter radiorelay stations.