Теория информации и кодирования в информационных системах
2017 Fourth International Conference on Engineering and Telecommunication
This paper concerns new effective method of joint data coding/modulation which may improve energy-efficiency and energy savings of modern wireless transmission systems. The method require a priori knowledge of probability distribution of input data to map them to the modulation symbols in the most efficient way.
The key idea of the proposed methods of Statistical Modulation is to map the most frequent input values into the modulation symbols with the lowest energy. To estimate the benefit we apply the approach to well-known Quadrature Amplitude Modulation (QAM): the most frequent input symbols are mapped to the most frequent QAM constellation pints. As the result, an average energy needed for data transmission is much smaller that allows increasing the distance between QAM constellation points for the same average energy. Therefore better Bit-Error-Rate (BER) is achievable for the same Signal-To-Noise-Ratio (SNR) in comparison with the standard QAM that does not utilizes the probabilities of input symbols.
In our research we have compared new SQAM and traditional QAM modulation (which does not utilizes the probabilities of input symbols) for the case of exponential distribution of input symbols. Our experiments and theoretical calculations shows that SQM for exponential input provides up to 3 dB gain in BER-SNR.
This method may be applied to improve BER-SNR and reduce the power consumption of the whole transmission system. The list of potential application areas includes M2M communications, IIoT, mobile networks and other scenarios that are critical to power consumption, battery life and latency.
We consider certain spaces of functions on the circle, which naturally appear in harmonic analysis, and superposition operators on these spaces. We study the following question: which functions have the property that each their superposition with a homeomorphism of the circle belongs to a given space? We also study the multidimensional case.
We consider the spaces of functions on the m-dimensional torus, whose Fourier transform is p -summable. We obtain estimates for the norms of the exponential functions deformed by a C1 -smooth phase. The results generalize to the multidimensional case the one-dimensional results obtained by the author earlier in “Quantitative estimates in the Beurling—Helson theorem”, Sbornik: Mathematics, 201:12 (2010), 1811 – 1836.
We consider the spaces of function on the circle whose Fourier transform is p-summable. We obtain estimates for the norms of exponential functions deformed by a C1 -smooth phase.