Özet:

The object of this research is the methods and algorithms of space-time block coding, which are also used in multi-antenna radio communication systems (Multiple Input Multiple Output – MIMO). The implementation of MIMO systems for coherent reception or precoding of data implies knowledge of information about the state of the communication channel and, accordingly, compensation for its impact. For channel estimation, together with information signals, pilot signals are transmitted, previously known at the receiving side. The frequency of sending these signals depends on factors that change the state of the communication channel, for example, one of which is the high speed of movement of mobile stations. But since the pilot signals do not carry user information, the resource of the system is consumed, which impedes the efficient use of the radio frequency spectrum. In the course of the study, a method was considered that admits the absence of the need for knowledge of the state of the communication channel – relative phase modulation, which was taken as a basis and distributed for use in MIMO systems. This method provides for incoherent reception, but, despite this, its use is fully justified, based on the results of the study. Effective tree coding and an algorithm for compensating the noise components of the received signal were also developed and integrated into the system. This, accordingly, allows to optimize the computational power of the system implementation and to approximate the proposed method of differential space-time block coding (DSTBC) to the methods of coherent reception. Using the MATLAB software package, the proposed DSTBC method is simulated for various options for the number of transmitting and receiving antennas and types of modulation. A comparison is made and the advantages of the DSTBC method are determined. The described method can find application in modern radio communication systems with rapidly changing communication channel parameters due to the high speed of movement of mobile stations. Author Biography Mikhail Tokar, Odessa National O. S. Popov Academy of Telecommunications, 1, Kuznechna str., Odessa, Ukraine, 65029; Taras Shevchenko Transnistria State University, 128, 25 Zhovtnia str., Tiraspol, Moldova, 3300 Postgraduate Student Department of Theory of Electrical Communications Senior Lecturer Department of Quantum Radiophysics and Communication Systems

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