I. Lavrenyuk1, S.B. Makarov2, A.S. Ovsyannikova3, S.V. Zavjalov4, T.Yu. Kudryashova5, V.S. Sinepol6, B.I. Polozhincev7

1-7 Peter the Great St. Petersburg Polytechnic University (St. Petersburg, Russia)

1 lavrenyuk_i@spbstu.ru; 2 makarov@cee.spbstu.ru; 3 ovsyannikova_as@spbstu.ru; 4 zavyalov_sv@spbstu.ru;
5 kudryashova_tyu@spbstu.ru; 6 sinepol@mail.spbstu.ru; 7 borisp@spbstu.ru

Formulation of the problem. In real data transmission systems, even for channel with additive white Gaussian noise, it is necessary to take into account the implementation aspects of the structure of the information system. These aspects include the features of packet data transmission, the construction of phase and clock synchronization. The boundary values of the communication channel efficiency are determined by Shannon's formula for throughput. Approximation to these boundary conditions will depend on the magnitude of energy losses caused by inaccuracies in the implementation of signal processing devices. This effect is especially evident in the case of using optimal signals with controlled intersymbol interference based on eigenfunctions of band-limited cores.

The goal is to determine an experimental assessment of the effect of real phase and clock synchronization on packet data transmission consisting of optimal signals with controlled intersymbol interference based on eigenfunctions of band-limited cores.

Results. It has been experimentally shown that packet message transmission formats with optimal signals leads to energy losses for channels with constant parameters. These energy losses are associated with inaccuracies in the practical implementation of phase and clock synchronization systems.

When using coherent processing algorithms with decision feedback and with the maximum likelihood estimation of subsequent symbols for fixed data rates R=1.25/T–2/T under real operating conditions of phase and clock synchronization, energy losses are equal to 1.8-1.9 dB for BER=10–3 and 2.1-2.4 dB for BER=10–4. Energy losses associated with the presence of real phase and clock synchronization increase if the signal-to-noise ratio increases more than 15 dB.

Practical significance. The effect of real phase and clock synchronization in packet data transmission consisting of optimal signals with controlled intersymbol interference based on eigenfunctions of band-limited cores is experimentally demonstrated. The results can be used in existing DVB-S2X systems, as well as to increase TV broadcasting channels, improve its quality, and provide additional services.

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