Vol 15, No 3 (2017)

Application of matrix methods for calculating the characteristics of reflective metamaterials composed of several planar layers based on a media with spatial dispersion and chirality discussed in the work. The surface impedance and transmission matrices of generalized layer received. As an example, the problem of plane electromagnetic wave of linear polarization reflection from two-layer dielectric-chiral metamaterial basing on a thin wire coils located in the air and double-chiral metamaterial on a perfectly conducting substrate are considered. Frequency dependencies of reflection and transmission coefficients modules of the main and cross-polarized field components at the different container geometrical and the chiral metamaterial inclusions dimensions are considered. Metastructure enables the conversion of normally incident radiation in the scattering in the plane of the structure at some frequencies. Ability to use double-chiral metastructure a protective coating for the metallized object is predicted.

In this paper considers the main features and problems of installation and operation of fiber-optic cable links of the oil-transmission structures of Western Siberia. Complex geological and climatic conditions, as well as the specifics of the construction of the pipeline system, could not but affect the implementation of the installation of technological fiber-optic cable lines. Harsh natural conditions not only impose specific requirements on the technology, cable and cable fittings used, but also require special approaches in the implementation of sanitary norms and ensuring the greatest possible comfort of people. Complex geological conditions, lack of infrastructure, low temperature set the task of introducing new technologies for organizing the installation of fiber-optic communication lines for the subsequent achievement of the maximum possible lifetime of communication cables. The necessity to perform works under extreme conditions (low negative temperature and high wind speed at the work at height on supports) leads to stricter requirements for all components of the technological process: specific requirements are imposed on machinery and equipment, the requirements for cables and the requirements for cable fittings are increased, the tolerances for the execution of technological operations are toughened, the role of the human factor is significantly increased and the price of error is significantly increased. All this has determined the special role of quality control. In the paper shows that one of the main problems of the employment of fiber-optic links in the extreme conditions of the North is the lack of relatively inexpensive field instruments for estimating the suitability of the optical cable. This does not allow to effectively control the quality of the work in conditions where the probability of error is high. Such measuring instruments can be implemented on the basis of BOTDR or POTDR. In both cases, development of an inexpensive field device is required. But POTDR potentially allows you to create a more versatile device.

A method of converting a series of stationary ergodic sources, leading to the construction codes nonequiprobability codewords. Based on the introduction of the minimum redundancy obtained construct, allowing using a simple one-dimensional signals to obtain the increment of the energy efficiency of data transmission systems (IMS). At the same time, the received code-signal constructions are close in characteristics to ensembles of biorthogonal signals, but they provide substantially better band efficiency. A comparison of the developed constructions with known methods of reducing unit costs in terms of frequency and energy efficiency. The article shows the possibility of using concatenated code-considered signal constructions with any method of block or convolutional coding, which provides an increase in the energy gain of the corresponding codes by 1,3 …3,2 dB.

The paper presents statistical approach to studying of amplitude-phase coupling shown by electrocardiograms (ECG) of healthy and sick people. ECG data were collected from a group of over 500 presumably healthy young people and from over 10 sick people. The article demonstrates the results of a detailed structural analysis of digital rows of systolic potential diagrams and cardiointervalogramms using histograms and standard deviation - information entropy charts. The authors pay a lot of attention to statistical data comparison. As a result, a parametric electrocardiogram coupling approach is proposed based on evident infocommunication links between structural parameters of amplitude and phase. Each infocommunication link is set to correspond to one experimental registration and is assigned an angle parameter. The set of such links represents the information model. It is shown that both the angle parameter and the information model have a specific sensitivity to prenosologic conditions. The qualitative and quantitative classification of the amplitude-phase coupling modes of the ECG data is presented, which is based on analyzing parametric coupling diagrams. The article will be of interest to physiologists and specialist in the field of information data analysis.

The article describes the method of energy efficiency increasing of OFDM wireless systems. It is suggested to use as a complex envelope of OFDM signal the difference between the signal and its extrapolated meaning to decrease dynamic range of signals without communication quality degradation. The scheme of generation and reception of compressed signal is developed. It is shown, that extrapolation can be implemented using Kalman filtering. The problem of extrapolator synthesizing was formulated and solved for the case of communication system synchronous operation mode. Orthogonality of compressed signals in in-phase and quadrature channels is proved, and the stability of the obtained solution for signal reception is proved. The efficiency of the proposed method is demonstrated using the example of the HSPA+ wireless system.

This paper is devoted to the methods for efficiency improvement of orthogonal frequency-division multiplexing that do not comprise additional computational complexity of signal processing algorithms on the transmitter maintaining the subcarriers orthogonality. Proposed method is based on applying the window function to the guard interval of symbol while the original part remains unchanged. This approach provides the off-frequency emission decrease, which depends on the selected fast Fourier transform mode, broadcasting standard, and shaping parameters for window function. The gain in off-frequency emission decrease is from 5% to 26% in contrast with the "rectangular" window function, the increase of symbol rate is up to 5%, and gain in spectral efficiency is up to 0.05%. The analysis of subcarriers frequency characteristics shows that reduce of resulting signal level by 2-4 dB compared to the raw symbol, which minimizes the frequency emissions at transient times between the guard interval and the useful part of the symbol.

With the development of robotics it became apparent that for a number of tasks (environmental monitoring, patrolling, correction of war systems, etc.), it is simple to use of relatively simple robots. Creating a complex system consisting of many identical devices increases its reliability, since the failure of one of the elements of a distributed network does not affect its survivability. Such systems are flexible and easily scalable, since they have the ability to reconfigure and add new devices. In science, a new scientific trend was formed - group robotics. This direction has specific problems: swarm intelligence, collective behavior of the decentralized self-organizing system, etc. To coordinate the actions of a group of robots redistributing roles between them, creating alternative routes for the transfer of information in the event of the removal or loss of communication with one of the nodes, it is necessary to constantly monitor the distances to neighboring nodes relative to each of the robots entering the swarm. The article provides methods for estimating the distances and quality of radio links, which can be useful for creating predictive models and monitoring the state of a swarm of robots united by a radio network.