Interference Immunity Assessment Identification Friend or Foe Systems

2021 ◽  
pp. 287-306
Author(s):  
Iryna Svyd ◽  
Ivan Obod ◽  
Oleksandr Maltsev
Keyword(s):  
Interference Immunity

scholarly journals Remote Reflectivity Sensor for Industrial Applications

Sensors ◽  
2021 ◽  
Vol 21 (4) ◽  
pp. 1301
Author(s):  
Federico Cavedo ◽  
Parisa Esmaili ◽  
Michele Norgia
Keyword(s):  
Low Cost ◽  
Cost Effective ◽  
Industrial Applications ◽  
Interference Immunity ◽  
Surface Reflection ◽  
Measurement Systems ◽  
Digital Detector ◽  
Reflected Light ◽  
Surface Optical ◽  
Diffused Light

A low-cost optical reflectivity sensor is proposed in this paper, able to detect the presence of objects or surface optical properties variations, at a distance of up to 20 m. A collimated laser beam is pulsed at 10 kHz, and a synchronous digital detector coherently measures the back-diffused light collected through a 1-inch biconvex lens. The sensor is a cost-effective solution for punctual measurement of the surface reflection at different distances. To enhance the interference immunity, an algorithm based on a double-side digital baseline restorer is proposed and implemented to accurately detect the amplitude of the reflected light. As results show, the sensor is robust against ambient light and shows a strong sensitivity on a wide reflection range. The capability of the proposed sensor was evaluated experimentally for object detection and recognition, in addition to dedicated measurement systems, like remote encoders or keyphasors, realized far from the object to be measured.

scholarly journals Potential interference immunity of coherent reception of quadruple phase-manipulated radio signal in the presence of coherent harmonic interference

2021 ◽  
pp. 45-54
Author(s):  
Vitalii Zvonarev ◽  
Aleksandr Popov
Keyword(s):  
Phase Shift ◽  
Radio Signal ◽  
Radio Channel ◽  
Energy Parameter ◽  
Interference Immunity ◽  
Probability Densities ◽  
Energy Ratios ◽  
Noise Ratio ◽  
The Given ◽  
Interference Phase

Introduction: The known methods for calculating the interference immunity of radio signal reception in the presence of, for example, harmonic interference, often lead to significantly different numerical values. Each calculation technique of this type has its own algorithm for the resulting formula output, and these conclusions are based on a different level of “engineering rigor”. Purpose: To develop, оn the basis of linear transformation of coordinates, a correct method for calculating the error probability in the correlating reception of a four-fold phase-manipulated radio signal in the presence of coherent harmonic interference. Methods: Four-dimensional probability density of a vector of output voltages of the demodulator correlators in a four-fold integral was represented by a product of one-dimensional probability densities in the space of eigenvectors of the covariance matrix, in which two probability densities are Dirac delta functions. The quadruple integral is brought to double, with new integration limits defined from the plane equations bounding the integration region in this space. Results: Formulas were derived for accurate calculation of average probabilities of symbol and bit errors in coherent reception of a four-fold phase-manipulated radio signal in the presence of coherent harmonic interference. The derived exact formulas were used to plot the dependencies of the average probabilities of symbol and bit errors on the signal-to-noise ratio for the given interference-to-noise ratio and the given interference phase shift relative to the signal phase. It has been studied how the energy ratios of the signal and interference, as well as the interference phase shift, affect the probabilities of symbol and bit errors. It was found that the influence of a non-energy parameter equivalently leads to a change in the energy ratios. Practical  relevance: The results of the research can be used in assessing the communication efficiency under interference. The developed technique will allow you to accurately determine the energy characteristics of a radio channel providing the required quality for the reception of transmitted messages in presence of harmonic interference.

scholarly journals SIMULATION MODELING OF THE INTERFERENCE IMMUNITY OF THE RADARS OPERATING WITH COMPRESSED SIGNAL

2020 ◽  
Vol 8 (12) ◽  
pp. 799-804
Author(s):  
Sevdalin Ivanov Spassov ◽  
Keyword(s):  
Simulation Modeling ◽  
Pulse Compression ◽  
Matched Filter ◽  
Chirp Signal ◽  
Interference Immunity ◽  
Matched Filters ◽  
Matlab Software ◽  
Interference Signals

The immunity to the interference of a radar operating with a pulse compression signal is an important feature. The matched filter is one of the elements of the radar, providing resistance to interference. A model of a matched filter to chirp signal has synthesized using the Simulink tool of the Matlab software. Two types of interference signals have fed to the matched filter input, and the output signals are measured. The matched filters degree of suppression against these two interference signals has been assessed. Inferences about the interference immunity of the radars operating with compressed signals have been made.

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