scholarly journals Study of Brain Radio Signals Using Bispectral Analysis

2021 ◽  
pp. 138-141
Author(s):  
B. A. Hovhannisyan
Keyword(s):  
Human Brain ◽  
Radio Signal ◽  
Emotional States ◽  
Bispectral Analysis ◽  
Spectral Components ◽  
Radio Signals ◽  
Sensor Probe

Using a special sensor (probe antenna-applicator), radio signals emitted by the human brain are recorded. The changes of different parameters are investigated while studying different physical and emotional states of people. The studies are carried out using spectral and bispectral analysis in the LabVIEW environment. It is shown that in a stressful state the bispectrum of the brain’s radio signal is significantly enriched, and many phase coupled spectral components appear. They undergo changes in their amplitude and frequency. The results of these studies may be useful for understanding the nature and identification of fast processes in the human brain.

RADIO FADING AND THE NATURAL ELECTROMAGNETIC BACKGROUND

1965 ◽  
Vol 43 (11) ◽  
pp. 1951-1961 ◽  
Author(s):  
H. J. Duffus ◽  
G. M. Boyd ◽  
J. K. Kinnear
Keyword(s):  
Radio Signal ◽  
Spectral Component ◽  
Broad Band ◽  
Auroral Zone ◽  
Frequency Range ◽  
Single Station ◽  
D Region ◽  
Radio Signals ◽  
Signal Fluctuation ◽  
The Difference

A comparison is made between the natural geomagnetic background in the frequency range 0.006–0.6 Hz and fluctuations of the difference in received signal strength between the two magnetoionic modes of vertically incident broad-band radio signals in the range 6–16 MHz, observed at a single station near Victoria, British Columbia. At this station the following points were observed:1. During the daytime there is often a spectral component common to the radio-signal fluctuations and to the natural geomagnetic background, even during quiet magnetic times. There is seldom phase coherence, however, except for a few minutes at a time.2. There is a small but highly significant (1%) linear correlation R = 0.33 between all the hourly mean amplitudes of the radio-signal fluctuation level and the hourly mean amplitudes of the natural geomagnetic background. The correlation coefficient rises as high as R = 0.71 at 1400–1500 local time, when only a particular hour of each day is considered. It is concluded that geomagnetic micropulsations in this frequency range are a better indicator of r-f. fluctuations than is the local Kp.3. At night, there is a relationship between the occurrence of Pt's and of r-f. fluctuation, although their frequency components are not usually as closely related as are those of the daytime regimes.It is suggested that geomagnetic micropulsations can couple exospheric or auroral zone fluctuations into the upper E or F regions strongly enough to produce observable radio-signal fluctuations at mid-latitudes, even during magnetically quiet times.Lack of correlation between micropulsations and phase fluctuations of 18 kHz signals observed over an E–W 100-km path, and 80 kHz observed over an E–W 3 300-km path suggests that significant coupling does not extend down to the D region during magnetically quiet times.

1H- and31P-MR spectroscopy of primary and recurrent human brain tumorsin vitro: malignancy-characteristic profiles of water soluble and lipophilic spectral components

2001 ◽  
Vol 14 (5) ◽  
pp. 307-317 ◽  
Author(s):  
Fritz-Georg Lehnhardt ◽  
Gabriele Röhn ◽  
Ralf-Ingo Ernestus ◽  
Matthias Grüne ◽  
Mathias Hoehn
Keyword(s):  
Human Brain ◽  
Mr Spectroscopy ◽  
Water Soluble ◽  
Spectral Components

On the characterization of VLF radio signal propagation in atmosphere in quite solar conditions

2020 ◽  
Author(s):  
Giovanni Nico ◽  
Aleksandra Nina ◽  
Anita Ermini ◽  
Pierfrancesco Biagi
Keyword(s):  
Radio Signal ◽  
Technological Development ◽  
Low Frequency ◽  
Lower Ionosphere ◽  
Signal Propagation ◽  
Temporal Variations ◽  
Seasonal Effects ◽  
Propagation Mode ◽  
Theory Approach ◽  
Radio Signals

<p>In this work we use Very Low Frequency (VLF) radio signals, having a frequency in the bands 20-80 kHz, to study the VLF signal propagation in the atmosphere quite undisturbed conditions by selecting the signals recorded during night. As a good approximation, we can model the propagation of VLF radio signals as characterized by a ground-wave and a sky-wave propagation mode. The first one generates a radio signal that propagates in the channel ground-troposphere, while the second one generates a signal which propagates using the lower ionosphere as a reflector. The VLF receivers of the INFREP (European Network of Electromagnetic Radiation) network are used. These receivers have been installed since 2009 mainly in southern and central Europe and currently the INFREP network consists of 9 receivers. A 1-minute sampling interval is used to record the amplitude of VLF signals. Long time-series of VLF signals propagating during night are extracted from recorded signals to study possible seasonal effects due to temporal variations in the physical properties of troposphere. A graph theory approach is used to investigate the spatial correlation of the aforementioned effects at different receivers. A multivariate analysis is also applied to identify common temporal changes observed at VLF receivers.</p><p>This work was supported by the Ministero dell'Istruzione, dell'Università e della Ricerca (MIUR), Italy, under the project OT4CLIMA. This research is supported by the Ministry of Education, Science and Technological Development of the Republic of Serbia, under the projects 176002 and III44002.</p>

scholarly journals The Deceleration of Radio/Light Transmission; A Collision Mechanism Dependent Radio Signal Emission, Transmission, and Reception

2021 ◽  
Author(s):  
Jing Zhang
Keyword(s):  
Light Transmission ◽  
Radio Signal ◽  
Slow Fading ◽  
Fast Fading ◽  
Before And After ◽  
Radio Signals ◽  
Electron Photon ◽  
The Relationship ◽  
Group Pattern ◽  
Collision Mechanism

Abstract The fast and slow fading of radio signal transmissions or laser beam itself and its spare light confirm the presence of two kinds of collisions --- electron-photon and photon-photon collision. Photon transmissions of radio signals are either in consecutive dense photon groups in slow fading process or widespread group pattern in fast fading form. The photon transmission shapes are irregular and dynamical changes. The radio frequency shift and the wavelength reduction by the calculation demonstrate decelerations of radio/light transmission speeds due to the gradual reduced distance between two consecutive photon groups along the transmission pathway. Photons from radio signals are able to affect electron movements in radio signal receiving process and electrons able to kick photons into space during radio signal emission. The pattern of free electron movement under the influence of local electromagnetic force in antenna is consistent with the randomly dynamic changes of radio signal in space. The fast fading is due to the collision of consecutive photon groups of signals in slow fading with free photons in space. The mathematical equation for the relationship between light/radio transmission speeds before and after photons collisions is established. The equation is confirmed by the calculations of well-known difference of light transmission speeds in different media. The gravities from Earth and Sun play little role during light/radio transmission.

scholarly journals The Deceleration of Radio/Light Transmission; A Collision Mechanism Dependent Radio Signal Emission, Transmission, and Reception

2021 ◽  
Author(s):  
Jing Zhang
Keyword(s):  
Light Transmission ◽  
Radio Signal ◽  
Slow Fading ◽  
Fast Fading ◽  
Before And After ◽  
Radio Signals ◽  
Electron Photon ◽  
The Relationship ◽  
Group Pattern ◽  
Collision Mechanism

Abstract The fast and slow fading of radio signal transmissions or laser beam itself and its spare light confirm the presence of two kinds of collisions --- electron-photon and photon-photon collision. Photon transmissions of radio signals are either in consecutive dense photon groups in slow fading process or widespread group pattern in fast fading form. The photon transmission shapes are irregular and dynamical changes. The radio frequency shift and the wavelength reduction by the calculation demonstrate decelerations of radio/light transmission speeds due to the gradual reduced distance between two consecutive photon groups along the transmission pathway. Photons from radio signals are able to affect electron movements in radio signal receiving process and electrons able to kick photons into space during radio signal emission. The pattern of free electron movement under the influence of local electromagnetic force in antenna is consistent with the randomly dynamic changes of radio signal in space. The fast fading is due to the collision of consecutive photon groups of signals in slow fading with free photons in space. The mathematical equation for the relationship between light/radio transmission speeds before and after photons collisions is established. The equation is confirmed by the calculations of well-known difference of light transmission speeds in different media. The gravities from Earth and Sun play little role during light/radio transmission.

Measurement-based Statistical Method for Estimating and Verifying Signal Coverage and Coverage Probability in Urban Microcells

2018 ◽  
Vol 8 (6) ◽  
pp. 74
Author(s):  
Joseph Isabona ◽  
Kingsley Obahiagbon
Keyword(s):  
Outage Probability ◽  
Communication Networks ◽  
Coverage Probability ◽  
Statistical Approach ◽  
Radio Signal ◽  
Signal Strength ◽  
Signal Coverage ◽  
Radio Signals ◽  
Coverage Quality

Customer’s complaints and concerns about radio signal coverage at their home are important trigger to performance relevant drive test in the relevant area to observe the coverage quality. In this paper, statistical approach has been employed to assess the quality of the radio coverage and outage probability based on measured radio signals in an established UMTS network, operational in Ikoyi, a typical urban microcell in Nigerian environment. The results shows that the quality of radio signals at the cell edge is very poor in locations 2 and 4, as they recorded poor coverage probability performance of 89.25% and 81.72% and high outage probability performance of 10.74% and 18.28% respectively. It is also observed that the smaller the fade margin, the higher the outage probability and the lower the coverage reliability. This implies that the smaller the fade margin, the smaller the received signal strength at the MS and the more likely outage events. Hence, sufficient signal strength is needed at the mobile terminals at locations 2 and 4 in order to achieve the outage probability and coverage reliability required to effectively operate cellular communication networks.

APPLICATION OF BLIND SIGNAL SEPARATION TECHNIQUES FOR DETECTION OF PHASE-SHIFTED RADIO SIGNALS

2021 ◽  
Author(s):  
Н.Ю. ЛИБЕРОВСКИЙ ◽  
Д.С. ЧИРОВ ◽  
Н.Д. ПЕТРОВ
Keyword(s):  
Radio Signal ◽  
Signal To Noise Ratio ◽  
Signal Separation ◽  
Blind Signal Separation ◽  
Signal To Noise ◽  
Separation Algorithm ◽  
Blind Signal ◽  
Radio Signals ◽  
Joint Cumulants ◽  
Mixing Matrix

Целью данной работы является исследование эффективности алгоритма слепого разделения сигналов (СРСв задаче обнаружения цифровых фазоманипулированных радиосигналов. Рассмотрены классические методы СРС и критерии независимости сигналов. Исследована модель алгоритма СРС, основанного на вычислении размешивающей матрицы, которая приводит совместные кумулянты второго и четвертого порядков к нулю. Для исключения тривиального решения накладываются дополнительные ограничения на дисперсии сигналов. Приводится система уравнений для нахождения коэффициентов размешивающей матрицы. Показан вид коэффициентов размешивающей матрицы, приводящей сигналы к некоррелированному виду. Доказана возможность аналитического решения уравнения, связанного с равенством совместного кумулянта четвертого порядка к нулю. По результатам моделирования алгоритма СРС показано, что предложенный алгоритм позволяет обеспечить прием ФМ-2 радиосигнала на фоне гауссовой помехи. Выигрыш в отношении сигнал-помеха составляет не менее 2 дБ. The purpose of this work is to study the effectiveness of the blind signal separation algorithm in the problem of detecting digital PSK radio signals. Classical methods of blind signal separation and criteria of signal independence are considered. A model of a blind signal separation algorithm based on the calculation of a mixing matrix that reduces the joint cumulants of the second and fourth orders to zero is investigated. To eliminate the trivial solution, additional restrictions are imposed on the signal variances. A system of equations for finding the coefficients of the mixing matrix is given. The view of the coefficients of the mixing matrix, which leads the signals to an uncorrelated form, is shown. The possibility of an analytical solution of the equation associated with the equality of the joint cumulant of the fourth order to zero is proved. Based on the results of the simulation of the blind signal separation algorithm, it is shown that the proposed algorithm allows receiving the PSK-2 radio signal against the background of Gaussian interference. The gain in the signal-to-noise ratio is at least 2 dB.

scholarly journals Calculating the probability of detecting radio signals from alien civilizations

2006 ◽  
Vol 5 (2) ◽  
pp. 143-149 ◽  
Author(s):  
Marko Horvat
Keyword(s):  
Radio Signal ◽  
Radio Communications ◽  
Radio Emissions ◽  
Starting Point ◽  
Radio Signals

Although it might not be self-evident, it is in fact entirely possible to calculate the probability of detecting alien radio signals by understanding what types of extraterrestrial radio emissions can be expected and what properties these emissions can have. Using the Drake equation as the obvious starting point, and logically identifying and enumerating constraints of interstellar radio communications, may yield the possibility of detecting a genuine alien radio signal.

scholarly journals Formation the radio signal for the system of space-time signal processing

2019 ◽  
Vol 30 ◽  
pp. 03011
Author(s):  
Yuri Gelozhe ◽  
Pavel Klimenko ◽  
Aleksander Maksimov
Keyword(s):  
Signal Processing ◽  
Automatic System ◽  
Radio Signal ◽  
Experimental Studies ◽  
Space Time ◽  
Time Signal ◽  
Digital Information ◽  
Destabilizing Factors ◽  
Radio Signals ◽  
The Stability

The work is devoted to digital information transmission systems using space-time signal processing. The formation of radio signals whose carrier frequencies are determined by the frequency-time matrices is considered. The signal shaper is based on a PLL system with a programmable frequency divider. The analysis of the processes in the phase automatic system under the influence of large destabilizing factors and frequency switching of the generated oscillations is carried out. It is theoretically and experimentally shown that in the above-mentioned conditions the automatic system may lose stability. The algorithm for controlling the PLL has been developed, which ensures the stability of processes under large disturbances. Experimental studies have been carried out that have shown the efficiency of the improved system.

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