DRM DIGITAL RADIO BROADCASTING TECHNOLOGY FOR CREATING GLOBAL COVERAGE NETWORK
Authors:   Moscow Technical University of Communication and Informatics, Varlamov Oleg V. 
Published: May 2023

The monograph considers DRM digital radio broadcasting technology for creating global coverage network. An analysis of the qualitative characteristics and efficiency of terrestrial broadcasting systems in various frequency bands was carried out. The issues of radio waves propagation and atmospheric radio noise are considered for the selected frequency range. Radio-frequency protection ratios were researched and the technical foundations of the frequency-territorial planning developed. Network parameters for the transitional period are determined. Requirements for the broadcasting network equipment characteristics were studied and solutions were developed for the use of antenna systems, transmitting and receiving equipment in digital mode. Based on the proposed method of large-cluster zones of single-frequency synchronous broadcasting in the LF range, the DRM digital radio broadcasting global coverage network topology was designed. The results of on-air experiments and field tests are presented. The studies were carried out using software and laboratory facilities developed by the author. Architecture of a digital broadcasting network in the Arctic region example was designed. The introduction substantiates relevance of the use of DRM standard digital broadcasting networks in large remote and sparsely populated areas with an underdeveloped telecommunications infrastructure for information, cultural and educational applications. The first chapter considers the DRM audio path qualitative characteristics and compares the coverage areas in AM and DRM modes. The effectiveness of broadcasting in different frequency bands is analyzed. Equipment and system standards reviewed. In the second chapter, broadcast transmitters for operation in the DRM mode are considered in detail. Attention is paid to digital transmitters, PWM modulator transmitters and outphasing transmitters. In the third chapter, the broadcast antennas operation features in the DRM mode are considered. Frequency extension circuits and its calculation method are proposed for electrically short antennas. The fourth chapter deals with the user receiver. Requirements for its characteristics and methods for measuring parameters are formulated. The possibility of providing the required DRM LF and MF ranges consumer receivers sensitivity is shown. In the fifth chapter, the issues of radio frequency protection ratios are studied, including those under the simultaneous action of several interfering signals. The parameters for transition period Simulcast mode - the ratio of analog and digital powers and the coverage area are determined. The sixth chapter deals with the issues of frequency-territorial planning (telecommunications network planning) in the LF and MF bands, including field strength variations in the daytime and at night, as well as the distribution of atmospheric radio noise levels over the Earth territory and industrial interference. The results of field experimental measurements in the LF and MF ranges, including the fading zone, are presented. The seventh chapter develops the DRM digital radio broadcasting network for global coverage topology. Preferred frequencies for broadcasting in different regions are determined. A method of large-cluster zones with a single-frequency synchronous network for the LF range is proposed, which makes it possible to organize round-the-clock year-round coverage of large areas. An example of topology development global network for the Arctic region is given. The main results of the author’s research reflected in this monograph are presented in conclusion.