scholarly journals Redistribution of Signals Power in Multipath System of Radio Communication

2019 ◽  
Vol 7 (4) ◽  
pp. 54-59
Author(s):  
W. I. Kaganov ◽  
F. Ki
Keyword(s):  
Communication Systems ◽  
Radio Signal ◽  
Scattering Matrix ◽  
Signal Power ◽  
Radio Communication ◽  
Microwave Transistor ◽  
Single Beam ◽  
Microwave Signals

Two types of satellite radio of communication systems are compared: single-beam and multibeam. The problem of summation and redistribution of radio signal powers of communication systems is discussed. The power redistribution of a group of microwave transistor amplifiers between different beams is analyzed. An adder circuit based on bridge quadrature devices is considered in two- and four-ray systems. For two such cases, the scattering matrix of the signal power adder was compiled. On the basis of these two cases it is possible to compose a scattering matrix for the number of summed powers of microwave signals with the number of rays equal to 8, 16 and 32.

scholarly journals Influence of Aircraft Power Electronics Processing on Backup VHF Radio Systems

Electronics ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 777
Author(s):  
Jan Leuchter ◽  
Radim Bloudicek ◽  
Jan Boril ◽  
Josef Bajer ◽  
Erik Blasch
Keyword(s):  
Power Electronics ◽  
Electromagnetic Interference ◽  
Communication Systems ◽  
Electromagnetic Compatibility ◽  
Intermediate Frequency ◽  
Radio Communication ◽  
Very High Frequency ◽  
Switching Power ◽  
Radio Systems ◽  
The Impact

The paper describes the influence of power electronics, energy processing, and emergency radio systems (ERS) immunity testing on onboard aircraft equipment and ground stations providing air traffic services. The implementation of next-generation power electronics introduces potential hazards for the safety and reliability of aircraft systems, especially the interferences from power electronics with high-power processing. The paper focuses on clearly identifying, experimentally verifying, and quantifiably measuring the effects of power electronics processing using switching modes versus the electromagnetic compatibility (EMC) of emergency radio systems with electromagnetic interference (EMI). EMI can be very critical when switching power radios utilize backup receivers, which are used as aircraft backup systems or airport last-resort systems. The switching power electronics process produces interfering electromagnetic energy to create problems with onboard aircraft radios or instrument landing system (ILS) avionics services. Analyses demonstrate significant threats and risks resulting from interferences between radio and power electronics in airborne systems. Results demonstrate the impact of interferences on intermediate-frequency processing, namely, for very high frequency (VHF) radios. The paper also describes the methodology of testing radio immunity against both weak and strong signals in accordance with recent aviation standards and guidance for military radio communication systems in the VHF band.

scholarly journals EDFA AND EYCDFA POWER BOOSTER FOR SECURED, HIGH SPEED AND MULTIPLE WAVELENGTH SERVICES IN OPTICAL COMMUNICATION SYSTEMS USING WDM AND QUAD-SINGLE FORWARD AND TRI BACKWARD PUMPING TECHNIQUE

2021 ◽  
Vol 5 (12) ◽  
Author(s):  
S. Semmalar ◽  
S. Malarkkan
Keyword(s):  
Wavelength Division Multiplexing ◽  
Optical Communication ◽  
Communication Systems ◽  
High Speed ◽  
Optical Power ◽  
Fiber Amplifier ◽  
Signal Power ◽  
Erbium Doped Fiber Amplifier ◽  
Output Optical Power ◽  
Wavelength Division

Proposed the EDFA and EYCDFA power booster (Erbium Doped Fiber Amplifier- Erbium ytterbium co doped fiber amplifier) with quad pumping for high speed and multi wavelength services in an optical communication. The proposed EDFA and EYCDFA power booster with WDM(Wavelength division multiplexing) simulated by dual forward and Backward pumping, Dual-backward pumping, Tri-single forward and dual backward pumping and Quadsingle forward and tri-backward pumping with respect to Pump power and fiber Length. The parameters Input Optical power, Output Optical power, Forward Signal power, Backward Signal power measured and determined the speed of transmission in all types of pumping methods. From that the proposed EDFA- ans EYCDFA power booster with WDM quad pumping is the best suitable for secured high speed optical telecommunication systems. The results shown in Quad pumping Output optical power is maximum 25.2dB and optimum spectral forward Signal power is 30.5dBm and very less spectral optical backward signal power of -25.4dBm with Length 5m

scholarly journals Implementation of the asynchronous signals reception method with the direct sequence spread spectrum

2020 ◽  
Vol 30 (2) ◽  
pp. 49-54
Author(s):  
I. V. Egorov ◽  
D. V. Gaivoronskii
Keyword(s):  
Spread Spectrum ◽  
Communication Systems ◽  
Block Diagram ◽  
Random Sequence ◽  
Direct Sequence Spread Spectrum ◽  
Practical Implementation ◽  
Direct Sequence ◽  
Radio Communication ◽  
Radio Stations ◽  
Synchronization Mechanisms

The physical and logical organization of most existing communication systems provides for additional options (transmission of known preambles, the presence of an additional synchronization channel) that simplify synchronization. At the same time, in the practical implementation of radio communication systems, it is necessary to solve the problems of developing additional synchronization mechanisms that can reduce the time it takes to synchronize to reduce energy consumption and increase channel capacity. Thus, the existing problem of the asynchrony of the generators of physically remote radio stations is relevant. One of the possible solutions is asynchronous signal reception with the direct sequence spread spectrum. It allows converting the original binary signal into a pseudo-random sequence for modulating the carrier. The current article is devoted to the characterization of this method and has the following items presented: the transmitter and receiver block diagram, sufficient to explain the proposed method; methods for compensating for effects arising from the asynchrony of the transmitter and receiver generators. Since synchronization is generated according to the correlation peaks that correspond to the data bits, it is possible to set the frequency of the chips on the transmitter to jitter artificially and supplement the pseudo-random sequence with several random chips, which complicates the unauthorized detection of the transmitted signal.

scholarly journals Link Quality Assessment Algorithm for Heterogeneous Self-organizing Maritime Communications Network

2018 ◽  
Vol 2 ◽  
pp. 32-40
Author(s):  
Krzysztof Bronk ◽  
Adam Lipka ◽  
Rafał Niski
Keyword(s):  
Quality Assessment ◽  
Cellular Networks ◽  
Communication Systems ◽  
Measurement Data ◽  
Link Quality ◽  
Radio Link ◽  
Radio Communication ◽  
Communications Network ◽  
Link Quality Indicator ◽  
Sea Area

The article introduces a method of performing a radio link quality assessment based on the Link Quality Indicator (LQI) which will be calculated for every system that is available. The method presented has been developed during the netBaltic project completed in Poland and generally applies to the so-called maritime zone A, i.e. the sea area where ships are still within the range of shore-based radio communication systems, particularly 3G/LTE cellular networks. The algorithm was developed based on the results of measurements obtained during two separate campaigns. That measurement data served as a basis for the method’s initial assumptions and was utilized during the method’s verification.

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