Ivanov Y. Error-correction decoding of turbo-codes in distributed computer systems

The research object is the process of communicating with the provision of the necessary reliability of data transmission for distributed computer systems. The research subject is methods and tools for turbo-codes decoding. The research aim is to increase the reliability of the data transmission and to reduce the computational complexity of decoding by improving the cascade turbo-code design in distributed computer systems of different functional purposes. Methods: methods of the probability theory and mathematical statistics, information theory and coding, approximation theory; analytical methods for the mathematical models research; simulation and experimental research. The theoretical results: for the first time has been developed turbo-decoder mathematical model with the simplified metrics and a posteriori values calculations; for the first time have been obtained analytical expressions for turbo-decoder computational complexity evaluation (SOVA, Bi-SOVA, PL-log-MAP decoding methods) with considering the number of encoder memory cells and symbols from the output of the encoder; has been proposed the new form of compensation function in the Jacobian logarithm in the turbo-decoder mathematical model, that allows to reduce the turbo-decoding computational complexity; has been modified log-MAP decoding method on the stage of metric and a posteriori decisions computations, that allows to increase the reliability of transmitting data comparatively with other existing turbo-decoding methods; has been further developed method for determining the computational complexity of the turbo-decoding with taking into account all elementary operations, which are implemented in the turbo-decoder. Practical results: have been developed a set of software and hardware tools to increase the reliability of transmitted data and to reduce the computational complexity of turbo-decoding methods without significant loss of decoding data efficiency in distributed computer systems. Degree of implementation: research results have been used in the working process of PE "TVA-Service" LLC "Medical Center "Altamedika plus", Vinnitsia National Medical and Technical Universities. Sphere (industry) of use: information and communication technologies.