scholarly journals FREQUENCY-INDEPENDENT LIMITS OF VALUES OF SYSTEM PARAMETERS OF CELLULAR COMMUNICATIONS AT MULTIPATH PROPAGATION OF RADIO WAVES IN URBAN AREA

Doklady BGUIR ◽  
2019 ◽  
pp. 117-124 ◽  
Author(s):  
V. I. Mordachev
Keyword(s):  
Mobile Communications ◽  
Electromagnetic Compatibility ◽  
Radio Channel ◽  
Cellular Communications ◽  
Radio Waves ◽  
Basic Principles ◽  
System Parameters ◽  
Radiated Power ◽  
Frequency Independent ◽  
Radio Equipment

The analysis was carried out in order to clarify the estimates of the expected restrictions on characteristics of new-generation mobile communications (4G, 5G) under the existing restrictions on radiated power of subscriber radio equipment, as well as in conditions where the boundaries of urban sites are outside of the area of free radio waves propagation (RWP) between subscriber and base stations. Analysis was performed using the basic principles and ensemble models of statistical theory of electromagnetic environment, as well as the basic principles of information theory that determines the radio channel capacity in presence of interference. Frequency-independent relationships have been obtained for estimating a number of system parameters of cellular communications under the conditions of multipath RWP in urban canyons and the presence of internal system interference: estimation the required equivalent isotropic radiated power (EIRP) of subscriber stations, the maximum data transmission capacity of the backward radio channel, the maximum distance of qualitative communication, and also the permissible level of internal radio interference at given requirements for communication range, and the information transfer rate of reverse radio channel taking into account the accepted restrictions on EIRP of subscriber radio equipment. The obtained relations allowus to estimate the limits of possible values of these system parameters of modern and future mobile communications; these relations also provide the opportunity to justify the quality requirements for ensuring the intra-system electromagnetic compatibility at the required data rate in backward radio channels of cellular networks and the existing restrictions on EIRP of subscriber stations.

scholarly journals Characteristics of the electromagnetic environment created by radiations of user equipment of ...4G/5G/6G cellular (mobile) communications in buildings

Doklady BGUIR ◽  
2021 ◽  
Vol 19 (6) ◽  
pp. 42-50
Author(s):  
V. I. Mordachev
Keyword(s):  
Wave Propagation ◽  
Radio Wave ◽  
Flux Density ◽  
Mobile Communications ◽  
Electromagnetic Compatibility ◽  
Radio Wave Propagation ◽  
Radio Waves ◽  
Interior Space ◽  
Power Flux ◽  
Near Zone

The goal of the work is to substantiate the technique for assessing the intensity of electromagnetic background generated by the set of radiating user devices of mobile communications in multi-storey buildings. For known empirical models of radio wave propagation in buildings, expressions are obtained for the probability distribution density and expectation of the power flux density of electromagnetic fields generated inside building by these sources from various parts of the building's interior space: from the near zone with radio wave propagation conditions similar to free space; and from the far zone, for which, along with intense attenuation of radio waves due to internal obstacles, a «quasi-waveguide» propagation of radio waves along corridors and industrial premises is also possible in certain directions. Relationships are obtained for the average levels of individual components of the electromagnetic background, determined as scalar sums of power flux density values of the fields generated by the sets of radiating devices of both the near zone and the far zone as a whole or its individual parts, characterized by different conditions of radio wave propagation. A method is proposed for assessing the electromagnetic background inside buildings based on approximation of sections of the inner surface of the premises in which the observation point is located, and the outer surface of the building, in the inner space of which radiation sources are randomly distributed, by the corresponding sections of the inner and outer spherical surfaces that are the subtend areas of the corresponding solid angles, in space elements of which a different spatial densities and radiation powers of sources and different conditions of radio wave propagation are possible. The results can be used to analyze the electromagnetic ecology of habitat and the electromagnetic safety of population at the full-scale implementation of 4G/5G/6G mobile communications, as well as to analyze the electromagnetic compatibility of systems using frequency bands for mobile communications on a primary and secondary basis.

scholarly journals 5 G communication network signal propagation models

Radiotekhnika ◽  
2021 ◽  
pp. 161-168
Author(s):  
Yu.Yu. Kolyadenko ◽  
N.А. Chursanov
Keyword(s):  
Communication Networks ◽  
Electromagnetic Compatibility ◽  
New Technology ◽  
Signal Propagation ◽  
Radio Waves ◽  
Radio Communication ◽  
Signal Attenuation ◽  
Floor Slabs ◽  
New Radio ◽  
Radio Equipment

The next generation 5G / IMT-2020 technology, like any new technology, brings its own specific features to all aspects related to the practice of its application. One of these particularly important aspects is electromagnetic compatibility. At the stage of preparation for the introduction of 5G radio networks, called NewRadio, it is necessary to take early measures to assess effectively the electromagnetic compatibility conditions for these networks based on a thorough analysis of the features of 5G technology. Correct and accurate assessments of these conditions means successful provision of the electromagnetic compatibility of radio equipment of new networks. The World Radio Communication Conference WRC-15 identified new radio frequency bands for 5G, including centimeter and millimeter wave bands. In general, this RF spectrum is located in three regions: below 1 GHz, 1 GHz to 6 GHz, and above 6 GHz (up to 100 GHz). From the EMC standpoint, the following can be distinguished as the main features of this spectrum: different nature of losses during signal propagation, in particular, a significant influence of additional factors (gases – oxygen, water vapor, etc.) on the level of losses previously unknown in cellular communication. The mathematical model of signal propagation of 5 G communication networks has been developed which takes into account: the attenuation of signals in free space; attenuation of signals caused by the influence of walls and floor slabs, loss of signal energy, when space is filled with various objects; attenuation of signals caused by loss of energy of radio waves, when propagating through rains; signal attenuation due to loss of radio wave energy due to fog; signal attenuation, when propagating through tree leaves, slow and fast random fading.

HYGIENIC ASSESSMENT OF ELECTROMAGNETIC RADIATION LEVELS OF BASE STATIONS,INSTALLED ON THE ROOFS OF BUILDINGS AND THE TERRITORY OF LAND PLOTS IN TASHKENT

2021 ◽  
Vol 2 (5) ◽  
pp. 5-11
Author(s):  
G. A. Tashpulatova ◽  
◽  
A. N. Krasavin
Keyword(s):  
Public Health ◽  
Electromagnetic Radiation ◽  
Flux Density ◽  
Energy Flux ◽  
Mobile Communications ◽  
Base Station ◽  
Base Stations ◽  
Cellular Communications ◽  
Measurement Results ◽  
Energy Flux Density

This article is about instrumental measurements of the FR EMR energy flux density. The measurement results were analyzed with the division of the data obtained by the purpose of buildings and the height of the antenna equipment placement, a hygienic assessment of the RF EMR levels created by the equipment of base stations of cellular communications, installed on the roofs of residential and public buildings and adjacent territories of Tashkent is given. A proposal is made on the rational placement of radio engineering facilities.Keywords:electromagnetic field; electromagnetic safety; base station for mobile communications; protection of public health; sanitary supervision

scholarly journals Time-Frequency Characteristics of In-Home Radio Channels Influenced by Activities of the Home Occupant

Sensors ◽  
2019 ◽  
Vol 19 (16) ◽  
pp. 3557
Author(s):  
Alireza Borhani ◽  
Matthias Pätzold ◽  
Kun Yang
Keyword(s):  
Radio Channel ◽  
Wearable Sensors ◽  
Fall Detection ◽  
The Body ◽  
Home Healthcare ◽  
Radio Waves ◽  
Time Frequency ◽  
Daily Life Activities ◽  
Data Files ◽  
The Impact

While aging is a serious global concern, in-home healthcare monitoring solutions are limited to context-aware systems and wearable sensors, which may easily be forgotten or ignored for privacy and comfort reasons. An emerging non-wearable fall detection approach is based on processing radio waves reflected off the body, who has no active interaction with the system. This paper reports on an indoor radio channel measurement campaign at 5.9 GHz, which has been conducted to study the impact of fall incidents and some daily life activities on the temporal and spectral properties of the indoor channel under both line-of-sight (LOS) and obstructed-LOS (OLOS) propagation conditions. The time-frequency characteristic of the channel has been thoroughly investigated by spectrogram analysis. Studying the instantaneous Doppler characteristics shows that the Doppler spread ignores small variations of the channel (especially under OLOS conditions), but highlights coarse ones caused by falls. The channel properties studied in this paper can be considered to be new useful metrics for the design of reliable fall detection algorithms. We share all measured data files with the community through Code Ocean. The data can be used for validating a new class of channel models aiming at the design of smart activity recognition systems via a software-based approach.

scholarly journals SYNTHESIS OF METHODS OF EVALUATION OF ELECTROMAGNETIC COMPATIBILITY OF RADIO-TECHNICAL SYSTEMS

2019 ◽  
pp. 57-65
Author(s):  
Natali Lukova-Chuiko ◽  
Volodymyr Nakonechnyi ◽  
Volodymyr Saiko ◽  
Serhii Toliupa
Keyword(s):  
Electromagnetic Fields ◽  
Electromagnetic Compatibility ◽  
Operating Conditions ◽  
Design Stage ◽  
Quality Level ◽  
Radio Engineering ◽  
Radio Electronic ◽  
Modern Development ◽  
Radio Equipment ◽  
Characteristic Features

Modern development of radio equipment is characterized by an increase in the speed of processes of transmission and processing of information, miniaturization and integration into unified complexes that physically bridles the sources and receptors of interference. All this leads to the strengthening of the requirements to ensure compliance with the conditions of electromagnetic compatibility and the need for its evaluation at the design stage of radio engineering devices and systems, because the incomplete or incorrect assessment of these requirements leads to a significant increase in time and material costs of the manufacturer, for further development of the development of electronic equipment and reduction its competitiveness. Widespread use of different purposeful electronic means leads to an increase in the levels of electromagnetic fields created by them in the surrounding space. These fields are obstacles for other similar devices, may degrade the operating conditions and reduce the effectiveness of their use. In this process, it is easy to see the characteristic features of dialectical development - progress in this area is restrained by the negative phenomena generated by its development. Further progress requires the overcoming of this trend, that is, development on a new quality level, which is to ensure the joint operation of various means. The key is that the actions of the electromagnetic fields, which are created by some technical means to the other, are carried out for the transmission of information, its processing, or vice versa, violation of the process of transmission and processing of data. Therefore, an analysis is proposed that allows preliminary prediction of the fulfillment of the conditions of electromagnetic compatibility in a group of radio-electronic means that have a number of sources of interference and radio engineering devices on which they affect. In this case, the important issue of checking the provision of electromagnetic compatibility of radio-electronic means is to determine the magnitude of the permissible power at which provides electromagnetic compatibility. The purpose of this article is to consider, from the general positions, the main tasks of the analysis and evaluation of the electromagnetic compatibility of radio-electronic means

scholarly journals NCREASING IMMUNITY OF DECAMETER RADIO CHANNEL TRANSMISSIONS UNDER UNINTENDED INTERFERENCE

T-Comm ◽  
2021 ◽  
Vol 15 (6) ◽  
pp. 4-9
Author(s):  
Sergey V. Dvornikov ◽  
◽  
Evgeniy V. Markov ◽  
Adjan A. Manoshi ◽  
◽  
...  
Keyword(s):  
Fading Channels ◽  
Rayleigh Fading ◽  
Noise Immunity ◽  
Radio Channel ◽  
Radio Waves ◽  
Radio Communication ◽  
Radio Channels ◽  
Shift Keying ◽  
Decameter Radio ◽  
Significant Length

The transmission of messages is a complex process, which is largely determined by the properties of the radio channel used. Decameter radio channels are the most difficult for organizing communication, since the ionospheric propagation of radio waves is associated with their significant attenuation, due to the significant length of the paths, as well as the presence of Rayleigh fading in the channel. However, the possibility of transmitting information over long distances without serious resource costs stimulates further research to improve the reliability of decameter radio communication. In this paper, we investigate the possibility of increasing the noise immunity of frequency-shift keying transmissions of decameter radio channels in conditions of unintentional interference due to the use of broadband signals. An analytical expression of the dependence of the probability of a bit error on the level of the ratio of the peak signal power to the peak interference power is considered; a graph of this dependence is presented. It is shown that the plot is consistent with the overall noise immunity estimate for Rayleigh fading channels using double FSK signals. The rationality of methods for obtaining the required reception quality in decameter radio channels is analyzed. It is shown that the most rational direction for increasing the noise immunity of FM-2 transmissions in decameter radio channels with Rayleigh fading in conditions of unintended interference is the use of broadband signals. In this case, for expansion, it is advisable to choose a value kf = 7, which makes it possible to increase the noise immunity by 9 dB. The conclusions are illustrated by graphs.

scholarly journals Assessment of vibration isolation in «Flexible connector–pipeline–vibration isolators Pendants» mechanical system

2020 ◽  
pp. 9-14
Author(s):  
Yu. A. Burian ◽  
◽  
A. V. Zubarev ◽  
S. N. Polyakov ◽  
◽  
...  
Keyword(s):  
Mechanical System ◽  
Vibration Isolation ◽  
Mechanical Resistance ◽  
Vibration Source ◽  
Vibration Isolators ◽  
Vibration Load ◽  
System Parameters ◽  
Radiated Power ◽  
Pipeline Vibration ◽  
Pumping Units

When designing pipeline systems, the question of reducing the vibration load transmitted from vibroactive elements (pumping units, compressors, etc.) through the pipelines to the base almost always arises. In this case, as a rule, when laying pipes, one end is connected to a vibration source through flexible elements (bellows, elastic compensators, pipes). The pipeline is installed on hangers with vibration dampers. The paper considers the issues of calculating the mechanical resistance of flexible connectors, pipelines and vibration isolators of suspensions, as well as analytical dependences and the results of numerical calculation of the forces transmitted to the base and the radiated power depending on the frequency. The graphic materials show the frequency characteristics of the forces on the base and vibration power, depending on the considered mechanical system parameters

scholarly journals Saturation and hysteresis effects in ionospheric modification experiments observed by the CUTLASS and EISCAT radars

2006 ◽  
Vol 24 (2) ◽  
pp. 543-553 ◽  
Author(s):  
D. M. Wright ◽  
J. A. Davies ◽  
T. K. Yeoman ◽  
T. R. Robinson ◽  
H. Shergill
Keyword(s):  
High Frequency ◽  
Radio Waves ◽  
Heating Facility ◽  
Ionospheric Modification ◽  
Radiated Power ◽  
Pump Waves ◽  
Hybrid Waves ◽  
Electron Density Irregularities ◽  
Uhf Radar ◽  
Field Aligned Irregularities

Abstract. The results of high latitude ionospheric modification experiments utilising the EISCAT heating facility at Tromsø are presented. As a result of the interaction between the high power pump waves and upper hybrid waves in the ionosphere, field-aligned electron density irregularities are artificially excited. Observations of these structures with the CUTLASS coherent HF radars and the EISCAT incoherent UHF radar exhibit hysteresis effects as the heater output power is varied. These are explained in terms of the two-stage mechanism which leads to the growth of the irregularities. Experiments which involve preconditioning of the ionosphere also indicate that hysteresis could be exploited to maximise the intensity of the field-aligned irregularities, especially where the available heater power is limited. In addition, the saturation of the irregularity amplitude is considered. Although, the rate of irregularity growth becomes less rapid at high heater powers it does not seem to fully saturate, indicating that the amplification would continue beyond the capabilities of the Tromsø heater - currently the most powerful of its kind. It is shown that the CUTLASS radars are sensitive to irregularities produced by very low heater powers (effective radiated powers <4 MW). This fact is discussed from the perspective of a new heating facility, SPEAR, located on Spitzbergen and capable of transmitting high frequency radio waves with an effective radiated power ~10% of that of the Tromsø heater (28MW).

QUASI-ELLIPTIC MICROSTRIP FILTER

2019 ◽  
pp. 75-80
Author(s):  
V. P. Razinkin ◽  
K. Ya. Aubakirov ◽  
T. G. Serikov
Keyword(s):  
Electromagnetic Compatibility ◽  
Radio Channel ◽  
Stop Band ◽  
Electronic Systems ◽  
Communication Line ◽  
Microstrip Filter ◽  
Elliptic Filter ◽  
Urgent Task ◽  
Microstrip Filters ◽  
Near Zone

Currently, modern telecommunication and radio-electronic systems widely use wireless information transmission technologies over the radio channel. Therefore, an urgent task is to ensure electromagnetic compatibility of a large number of simultaneously operating radio facilities using high-selective bandpass filters. This paper presents circuit solutions for microstrip filters using incomplete inclusion of loads and communication elements. This construction makes it possible to obtain additional attenuation poles in the near zone of the stop band, which frequencies are determined by the load inclusion factor. It is proposed to include a capacitor in the middle of the microstrip communication line to improve the selective properties. This made it possible to increase the order of the filter at constant dimensions. The frequency characteristics of a high-selective quasi-elliptic filter are given.

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