G.V. Ovechkin - Dr. Sc. (Eng.), Department "Computational and Applied Informatics", Ryazan State Radio Engineering University. E-mail: g_ovechkin@mail.ru
D.A. Shevlyakov - Post-graduate Student, Programming Engineer, Department "Computational and Applied Informatics", Ryazan State Radio Engineering University. E-mail: dima-shevlyakov@yandex.ru

Object of research in article is the method of decoding for error-correction codes, intended for correction of errors in a communication channel and called by the multithreshold decoder (MTD). It is known that in channels with independent errors this method carries out near optimal decoding even very long codes only with linear from code length implementation complexity, providing the coding gain levels comparable to the gain from the best methods of decoding for turbo and the low-density parity-check codes. Examples of encoding and decoding schemes, presented in article, and also the presented FPGA version of MPD decoder illustrate simplicity of the method. It is noted that in real channels because of multipath signal propagation, Doppler shift and many other reasons character of errors is much more complex as errors are grouped in packages. Along with error-correction coding in multipath channels with a dying down such technologies are applied to increase of reliability, as orthogonal frequency division multiplexing (OFDM), the data transmission organization by multiple input and multiple output antennas (MIMO technology), etc. In work the actual research problem of MTD efficiency in such more difficult conditions which decision will significantly expand a scope of this surprisingly simple and at the same time effective method is put and solved. At research such typical multipath channel models, as channels with the independent and correlated Rayleigh and Rice fading, the channel models recommended by sector of a radiocommunication of the International union of telecommunication (ITU-R), and also the multipath channel models (Spatial Channel Model) recommended by consortium 3GPP were used. To increase of reliability of data transmission together with MTD authors applied such technologies, as OFDM and MIMO. Results of modeling for MTD when using various types of modulation and demodulation were compared to the results provided with the best known methods of error correction, such as decoders for turbo and low-density parity-check codes recommended by standards of a wireless communication. The presented results showed that MTD providing high efficiency in Gaussian channels, are capable to fight against errors in much more difficult conditions of application, providing coding gain comparable (or even slightly better) with gain of decoders for turbo and the low-density parity-check codes.