I. Lavrenyuk1, S.B. Makarov2, S.V. Zavjalov3, G.P. Zhabko4, T.Yu. Kudryashova5, V.S. Sinepol6

1-6 Peter the Great St. Petersburg Polytechnic University (St. Petersburg, Russia)

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

Formulation of the problem. The computational complexity of reception algorithms increases when transmitting data at speeds above the Nyquist limit. The most economical in terms of computational costs are algorithms for element-by-element coherent reception with decision feedback.

The goal is to determine the growth of the computational complexity of the processing algorithm with decision feedback and the most reliable estimate of subsequent symbols. We used spectrally efficient signals with controlled intersymbol interference at transmission rates above the Nyquist limit.

Results. A method for estimating energy losses with increasing data rate for a fixed error probability is proposed. It is shown that an increase in the data rate by 1.5 times higher than the Nyquist limit leads to an increase in the energy loss by 2.5 dB for a fixed computational complexity of the processing algorithm and a fixed error probability BER = 10–4. It is also shown that with an acceptable increase in energy loss, for example, 2 dB, an increase in the data rate by 1.5 times leads to an increase in the computational complexity from 0.8 105 to 3.3 105 number of operations.

Practical significance. The decision feedback algorithms for processing spectrally efficient signals can be used in the hardware of DVB-S2/S2X satellite digital broadcasting systems, as well as in the channels of data transmission systems of interactive broadcasting systems.

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