The Modem Equipment Based on SDR-Technology for New Generation Tropospheric Stations

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 of features of the modem equipment construction of new generation tropospheric stations that can provide high data transfer rates with guaranteed quality of service in complex stationary and non-stationary noise inherent in tropospheric channels. Methods. The goal is achieved by using new technical and architectural solutions to build SDR based 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 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 was proposed. The configuration variants of modem equipment in relation to the modes of operation of compact troposcatter station were proposed. Conclusions. The proposed ways to improve the effectiveness of modem equipment allow realizing compact troposcatter radiorelay stations with a high rate of data transmission.