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Subject and Purpose. The paper presents a building concept of a promising meteor-burst communication system with enhanced bandwidth, noise immunity and covert operation of the system. Methods and Methodology. The proposed methods and technical solutions include selection of meteor-burst communication network topologies and employment of code division multiplexing and software-controlled intelligent antennas (SMART antennas) with adaptive techniques in view of varying operating conditions. Results. A meteor-burst communication network has been proposed in several topology variants providing a means of a simultaneous assess of subscriber stations to several base stations of the network, with both subscriber and base stations employing SMART antennas. It has been shown that the software-controlled pointing of these antennas should take into account seasonal changes in the radiant density of the sporadic meteor complex, implying that the radiation pattern maxima should be placed in the most probability areas of the appropriate meteor tracks, with pattern nulls located on the interference source directions. Signals with direct sequence spread spectrum have proved themselves well against interference fading. For these signals, digital processing techniques have been suggested. Conclusion. It has been shown that the proposed concept of enhanced bandwidth, noise immunity and covert operation of the meteor-burst communication system, as well as its subsequent refinement, is expedient to implement through the use of Software Defined Radio, SDR.

Subject and Purpose. The paper presents a technology of constructing a promising meteor-burst communication system (MBCS) with code division multiplexing. It increases the bandwidth and improves the noise immunity and covert operation of the system. Methods and Methodology. The proposed technology is based on software-defined radio (SDR) and provides MBCS adaptation to the environment conditions by means of software parameter control of the signals and their transfer protocols. It includes a technique of forming a large ensemble of signals with a direct sequence spread spectrum and improved auto- and cross-correlation properties, involves the optimal reception and matched digital filtering of large-base signals. In order to improve the noise immunity, the narrow-band interference rejection in the signal spectrum is proposed and is jointly software installed with the matched filtering. The detection and synchronization techniques effectively working in the non-Gaussian and non-stationary interference conditions gained consideration. Results. A method of forming a large ensemble of direct sequence spread spectrum signals with improved auto- and cross-correlation properties has been software implemented using a pseudorandom permutation of codeword elements of a maximum-length register code. Designed with the use of fast Fourier transforms, algorithms of digital matched filtering and interference rejection as applied to large-base signals have been implemented via field-programmable gate arrays (FPGA). A method of detection and synchronization of large-base signals has been proposed and software implemented on the FPGA basis. Conclusion. The proposed algorithms and their implementation methods make it possible to increase the bandwidth, improve noise immunity and enhance covert operation of the meteor-burst communication system with code division multiplexing.