Nonreciprocity of radio waves in a meteor radio channel

1988 ◽  
Vol 31 (5) ◽  
pp. 395-399
Author(s):  
A. N. Pleukhov
Keyword(s):  
Radio Channel ◽  
Radio Waves ◽  
Meteor Radio

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 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.

Lateral propagation of radio waves on the Dushanbe-Leninabad meteor radio path (preliminary results)

1987 ◽  
Vol 30 (3) ◽  
pp. 268-270
Author(s):  
A. V. Karpov ◽  
A. Kodirov ◽  
K. Mirdzhamalov ◽  
L. N. Rubtsov
Keyword(s):  
Radio Waves ◽  
Preliminary Results ◽  
Radio Path ◽  
Meteor Radio ◽  
Lateral Propagation

scholarly journals DIAGNOSTICS OF THE STOCHASTIC IONOSPHERIC CHANNEL IN THE DECAMETER BAND OF RADIO WAVES

2020 ◽  
Vol 6 (4) ◽  
pp. 66-73
Author(s):  
Nikolay Afanasiev ◽  
Stanislav Chudaev
Keyword(s):  
Radio Channel ◽  
Signal Transmission ◽  
Three Dimensional ◽  
Doppler Frequency ◽  
Time Correlation ◽  
Statistical Characteristics ◽  
Radio Waves ◽  
Probe Signal ◽  
Signal Characteristics ◽  
Ionospheric Channel

We propose a method for direct diagnostics of a stochastic ionospheric radio channel. This method can recalculate probe signal characteristics into transmitted signal characteristics. We derive analytical equations of second-order statistical moments for trajectory characteristics of the main and probe signals propagating in a three-dimensional randomly inhomogeneous ionosphere. We take into account boundary conditions at signal transmission and reception points. As a model of random irregularities of permittivity of the ionosphere, we utilize the concept of a changing space-time correlation ellipsoid, which is self-consistent with spatial changes in the average ionosphere. Time fluctuations of random irregularities are taken into account by the hypothesis of frozen transfer. We use analytical relationships to calculate the expected statistical characteristics of decameter signals along oblique probing paths of the ionosphere. An operational numerical algorithmization of the formulas derived is proposed. We report results of numerical experiments to determine the expected phase variances, group delay, and Doppler frequency shift of the main signal on a given single-hop path, based on measurements of these characteristics of a probe signal on a secondary path. We demonstrate the efficiency of the proposed method for diagnosing statistical trajectory characteristics of a decameter signal along single-hop paths under conditions when ground points of transmission and reception of the main and probe signals are outside the vicinity of focusing points of the wave field.

scholarly journals DIAGNOSTICS OF THE STOCHASTIC IONOSPHERIC CHANNEL IN THE DECAMETER BAND OF RADIO WAVES

2020 ◽  
Vol 6 (4) ◽  
pp. 77-85
Author(s):  
Nikolay Afanasiev ◽  
Stanislav Chudaev
Keyword(s):  
Radio Channel ◽  
Signal Transmission ◽  
Three Dimensional ◽  
Doppler Frequency ◽  
Time Correlation ◽  
Statistical Characteristics ◽  
Radio Waves ◽  
Probe Signal ◽  
Signal Characteristics ◽  
Ionospheric Channel

We propose a method for direct diagnostics of a stochastic ionospheric radio channel. This method can recalculate probe signal characteristics into transmitted signal characteristics. We derive analytical equations of second-order statistical moments for trajectory characteristics of the main and probe signals propagating in a three-dimensional randomly inhomogeneous ionosphere. We take into account boundary conditions at signal transmission and reception points. As a model of random irregularities of permittivity of the ionosphere, we utilize the concept of a changing space-time correlation ellipsoid, which is self-consistent with spatial changes in the average ionosphere. Time fluctuations of random irregularities are taken into account by the hypothesis of frozen transfer. We use analytical relationships to calculate the expected statistical characteristics of decameter signals along oblique probing paths of the ionosphere. An operational numerical algorithmization of the formulas derived is proposed. We report results of numerical experiments to determine the expected phase variances, group delay, and Doppler frequency shift of the main signal on a given single-hop path, based on measurements of these characteristics of a probe signal on a secondary path. We demonstrate the efficiency of the proposed method for diagnosing statistical trajectory characteristics of a decameter signal along single-hop paths under conditions when ground points of transmission and reception of the main and probe signals are outside the vicinity of focusing points of the wave field.

scholarly journals The diagnostics of HF radio channel on the base of backscatter ionosphere sounding data with continuous chirp signal

2018 ◽  
Vol 4 (2) ◽  
pp. 47-54
Author(s):  
Сергей Пономарчук ◽  
Sergey Ponomarchuk ◽  
Виктор Грозов ◽  
Viktor Grozov ◽  
Галина Котович ◽  
...  
Keyword(s):  
Real Time ◽  
Communication Systems ◽  
Radio Channel ◽  
Automatic Processing ◽  
Chirp Signal ◽  
Radio Waves ◽  
Front Edge ◽  
Radio Frequencies ◽  
Ionospheric Sounding

Backscatter ionospheric sounding (BIS) is a powerful tool for monitoring and predicting conditions of operation of HF communication systems. The BIS method is adopted to determine coverage areas of radio waves and maximum usable radio frequencies, distance along the ground to a scatterer, as well as to gain information about ionospheric structure and conditions. To solve these problems, we propose a method for direct diagnostics of HF radio channel at the front edge of BIS signals on ionograms. The method relies on real-time automatic processing and interpretation of BIS ionograms. We present algorithms for determining the maximum usable frequencies and characteristics of oblique sounding signals from current BIS data, without correcting ionospheric parameters. We realize the algorithm for recovering ionospheric parameters at the path midpoint.

Experimental study of nonreciprocity of a meteor radio channel

1992 ◽  
Vol 35 (1) ◽  
pp. 66-67 ◽  
Author(s):  
A. E. Bazlov ◽  
T. V. Kazakova ◽  
A. R. Kurganov ◽  
R. R. Merzakreev ◽  
V. V. Sidorov ◽  
...  
Keyword(s):  
Experimental Study ◽  
Radio Channel ◽  
Meteor Radio

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 Diagnostics of HF radio channel: based on data from backscatter ionospheric sounding by continuous chirp signal

2018 ◽  
Vol 4 (2) ◽  
pp. 17-23
Author(s):  
Сергей Пономарчук ◽  
Sergey Ponomarchuk ◽  
Виктор Грозов ◽  
Viktor Grozov ◽  
Галина Котович ◽  
...  
Keyword(s):  
Real Time ◽  
Communication Systems ◽  
Radio Channel ◽  
Leading Edge ◽  
Automatic Processing ◽  
Chirp Signal ◽  
Radio Waves ◽  
Radio Frequencies ◽  
Ionospheric Sounding

Backscatter ionospheric sounding (BIS) is a powerful tool for monitoring and predicting conditions of operation of HF communication systems. The BIS method is adopted to determine coverage areas of radio waves and maximum usable radio frequencies, distance along the ground to a scatterer, as well as to gain information about ionospheric structure and conditions. To solve these problems, we propose a method for direct diagnostics of HF radio channel at the leading edge of BIS signals on ionograms. The method relies on real-time automatic processing and interpretation of BIS ionograms. We present algorithms for determining the maximum usable frequencies and characteristics of oblique sounding signals from current BIS data, without correcting ionospheric parameters. We realize the algorithm for recovering ionospheric parameters at the path midpoint.

Computer model of a meteor radio channel

1995 ◽  
Vol 38 (11) ◽  
pp. 767-773 ◽  
Author(s):  
A. V. Karpov
Keyword(s):  
Computer Model ◽  
Radio Channel ◽  
Meteor Radio
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