Сигнально-кодовые конструкции для работы в условиях мощных полосовых помех
In this paper, we consider data transmission in “bad” channels with low snr and wideband interference. We propose a code construction based on frequency shift keying with fast frequency hopping having the rate of 1.5 bit per OFDM symbol. This code construction allows transmitting data in channels with string wideband interference and high noise levels, including with SIR equal to -30 dB and SNR equal to -9 dB. We also propose two new decoders that are more robust in regard to interference compared with the known OSN decoder. The first one, based on the Kolmogorov-Smirnov criterion, is more robust in case of very strong interference, while the second decoder has a wider working range for weaker interference and interference with narrower band. The computer simulation has shown that the proposed decoders have higher error correction efficiency than the previously known decoder. Thus, they can be recommended for use in real systems.
Statistical decoders are one of the most robust decoders for positional modulations like FSK and PPM. As we show in this work they are applicable to any (unknown) channels that have non-zero distance between received signals. This makes it possible to use statistical decoders in NOMA random access communication systems with bad Channel State Information. In this work we consider the problem of data transmission over unknown memoryless channels. To the author's knowledge this problem was not studied in literature till now. We propose repetition Kautz-Singleton codes and statistical decoders as a solution to this problem. To estimate the performance of the proposed solution we propose a lower and an upper asymptotic bounds on error rate for statistical decoder. These bounds are evaluated for Kolmogorov-Smirnov goodness-of-fit criteria and compared to a computer simulation. The lower bound seems to be close to the simulation result. The upper bound is not that close to the simulation result but it still holds. To the author's knowledge this is the first technique to derive bounds on error rate for any distance-based statistical decoder. These bounds for the Kolmogorov-Smirnov goodness-of-fit criterion also show that the error rate should be inversely proportional to the square root of code distance. Other goodness-of-fit criteria might yield asymptotically better results.
This work is devoted to the problems of information transmission with frequency shift keying and fast frequency hopping in special channels where the signal/noise ratio is low, and a high energy interfering signal is present. We propose a demodulation algorithm that is significantly more stable to the influence of a powerful interfering signal as compared to other known algorithms. Under these conditions, we show a statistical criterion that lets one significantly reduce error probability on the demodulator’s output. For the chosen criterion we prove several lemmas that let us speed up the demodulation algorithm. Computer modeling results show that the proposed demodulation algorithm has better correcting ability under a powerful interfering signal than previously known ones.
In the previous works we have considered decoding coded FSK modulation (similar to Kautz-Singleton codes) transmitted in a channel with strong interference by using a two-sample goodness-of-fit statistics. In this work we consider the applicability of different one-sample goodness-of-fit statistics for the decoding. Using a computer simulation we show that using these statistics may yield lower error rates relative to the known decoders. The most notable of them are Anderson Darling statistic that has the lowest error rates for narrow-band interference and Pearson's x2 and Kuiper statistics that are more resilient to wide-band interference. We can conclude that one-sample goodness-of-fit statistics can be used for Kautz-Singleton codes decoding with relatively low error rates in case of strong interference in the channel.
In previous papers we have considered fast-frequency hopping frequency shift keying. We have proposed a decoder with low error rate in channels with low signal to interference ratio. This decoder uses the Kolmogorov-Smirnov criterion statistics to differentiate transmitted codeword from others. In this paper we consider different goodness-of-fit criterion to improve the decoder error rate. We have discovered that the decoder based on the Barnett-Eison criterion have lower error rates in wideband interference scenario, while the one based on the Anderson criterion is better in case of narrowband interference.
Generalized error-locating codes are discussed. An algorithm for calculation of the upper bound of the probability of erroneous decoding for known code parameters and the input error probability is given. Based on this algorithm, an algorithm for selection of the code parameters for a specified design and input and output error probabilities is constructed. The lower bound of the probability of erroneous decoding is given. Examples of the dependence of the probability of erroneous decoding on the input error probability are given and the behavior of the obtained curves is explained.
The dynamics of a two-component Davydov-Scott (DS) soliton with a small mismatch of the initial location or velocity of the high-frequency (HF) component was investigated within the framework of the Zakharov-type system of two coupled equations for the HF and low-frequency (LF) fields. In this system, the HF field is described by the linear Schrödinger equation with the potential generated by the LF component varying in time and space. The LF component in this system is described by the Korteweg-de Vries equation with a term of quadratic influence of the HF field on the LF field. The frequency of the DS soliton`s component oscillation was found analytically using the balance equation. The perturbed DS soliton was shown to be stable. The analytical results were confirmed by numerical simulations.
The conference “2021 Systems of signals generating and processing in the field of on board communications” is organized with technical sponsorship of Russian (Moscow) IEEE Circuits and Systems (CAS04) Chapter IEEE Region 8, Russian Section Chapter, MTT/ED and Institute of Radio and Information Systems Association (IRIS), Vienna, Austria. The conference featured invited researchers, educators, managers, and graduate students, whose research activity, case studies or best practices, are shedding light on the theory or practice of engineering, include modern digital transportation systems design and technical operation, radio waves propagation, transmitting, receiving and processing signals in television and radio broadcasting devices, information technologies in transport. The main areas of the conference “Systems of signals generating and processing in the field of on board communications” include modern digital transportation systems design and technical operation, radio waves propagation, transmitting, receiving and processing signals in television and radio broadcasting devices, information technologies in transport. FIELD OF INTEREST: Components, Circuits, Devices and Systems; General Topics for Engineers; Signal Processing and Analysis. Reports presented at the conference are grouped in 6 sections: 1. Antennas and Radio Waves Propagation. 2. Navigation and Mathematical Algorithms of an Object Space Orientation. 3. Radiofrequency Applications. 4. Wire and Optical Communication and Control Systems. 5. Intelligent Transport Systems (ITS): Sub-section 1: Use of digital ITS infrastructure in telematic control systems on urban passenger transport Sub-section 2: Peculiarities of data exchange in cooperative ITS Sub-section 3: Theoretical Aspects of Artificial Intelligence Systems Development for Transportation Engineering Sub-section 4: Test methods of motor vehicles integrated into an intelligent transport environment 6. Digital signal processing in on-board radio systems
Radiation conditions are described for various space regions, radiation-induced effects in spacecraft materials and equipment components are considered and information on theoretical, computational, and experimental methods for studying radiation effects are presented. The peculiarities of radiation effects on nanostructures and some problems related to modeling and radiation testing of such structures are considered.