scholarly journals Adaptive algorithm based on antenna arrays for radio communication systems

2017 ◽  
Vol 14 (3) ◽  
pp. 301-312 ◽  
Author(s):  
Valentin Fedosov ◽  
Andrey Legin ◽  
Anna Lomakina
Keyword(s):  
Wireless Networks ◽  
Antenna Arrays ◽  
Data Transmission ◽  
Communication Systems ◽  
Electromagnetic Compatibility ◽  
Signal Propagation ◽  
Time Signal ◽  
Adaptive Antenna ◽  
Spatial Coding ◽  
Multiple Input

Trends in the modern world increasingly lead to the growing popularity of wireless technologies. This is possible due to the rapid development of mobile communications, the Internet gaining high popularity, using wireless networks at enterprises, offices, buildings, etc. It requires advanced network technologies with high throughput capacity to meet the needs of users. To date, a popular destination is the development of spatial signal processing techniques allowing to increase spatial bandwidth of communication channels. The most popular method is spatial coding MIMO to increase data transmission speed which is carried out due to several spatial streams emitted by several antennas. Another advantage of this technology is the bandwidth increase to be achieved without expanding the specified frequency range. Spatial coding methods are even more attractive due to a limited frequency resource. Currently, there is an increasing use of wireless communications (for example, WiFi and WiMAX) in information transmission networks. One of the main problems of evolving wireless systems is the need to increase bandwidth and improve the quality of service (reducing the error probability). Bandwidth can be increased by expanding the bandwidth or increasing the radiated power. Nevertheless, the application of these methods has some drawbacks, due to the requirements of biological protection and electromagnetic compatibility, the increase of power and the expansion of the frequency band is limited. This problem is especially relevant in mobile (cellular) communication systems and wireless networks operating in difficult signal propagation conditions. One of the most effective ways to solve this problem is to use adaptive antenna arrays with weakly correlated antenna elements. Communication systems using such antennas are called MIMO systems (Multiple Input Multiple Output multiple input - multiple outputs). At the moment, existing MIMO-idea implementations do not always noticeably accelerate traffic at short distances from the access point, but, they are very effective at long distances. The MIMO principle allows reducing the number of errors in radio data interchange (BER) without reducing the transmission rate under conditions of multiple signal re-reflections. The work aims at developing an adaptive space-time signal algorithm for a wireless data transmission system designed to improve the efficiency of this system, as well as to study the efficiency of the algorithm to minimizing the error bit probability and maximizing the channel capacity.

Prospects for the Application of the Global High-speed, Low Latency Broadband Satellite Internet in the Field of Road Transport

2021 ◽  
pp. 254-264
Author(s):  
Anatoliy Soltus ◽  
◽  
Maksym Rud ◽  
Keyword(s):  
Antenna Arrays ◽  
Communication Systems ◽  
High Speed ◽  
Electromagnetic Compatibility ◽  
Emerging Market ◽  
Satellite Communications ◽  
Road Transport ◽  
Unmanned Vehicles ◽  
Low Latency ◽  
Current State

The article examines the problems of navigation and communication with the use of satellite technologies in road transport in the context of the growth of globalization processes in the world economy and the transformations of freight transport technologies caused by a large-scale transition to transport with zero emissions and the development of unmanned vehicles. The paper discusses the principles of building a global high-speed broadband satellite Internet with low latency. Potential capabilities of technologies such as digital antenna arrays and laser communication channels used in such systems are analyzed. Also considered are the existing and potential problems, both technical with electromagnetic compatibility with existing satellite communication systems and between systems under construction or planning, and legal caused by changes in the principles of information transfer at the interstate level. The main players in the emerging market of high-speed satellite communications are considered and the parameters of the systems declared by them are described. The comparison of the current state of building satellite constellations of individual projects is carried out and the ability to implement the announced plans by individual companies is analyzed. The disadvantages that create obstacles for the introduction of high-speed satellite communications in road transport at the moment and the directions of their overcoming are highlighted. Considering the potential of satellite Internet systems, the current state of construction, as well as existing technical and legal restrictions, the introduction of reliable satellite communications will significantly speed up the transition to autonomous unmanned vehicles. In this regard, the most successful opportunities for the new communication technology will be able to realize the transport companies, which will simultaneously update the fleet of vehicles towards zero emissions and with unmanned technologies.

scholarly journals Technique of radio suppression of a radio communication system in a Wі­Fі network from noise­like signals based on the HTTP/3 рrotocol

Connectivity ◽  
2020 ◽  
Vol 145 (3) ◽  
Author(s):  
V. M. Cherevyk ◽  
◽  
A. V. Glushchuk
Keyword(s):  
Data Transmission ◽  
Communication Systems ◽  
Electromagnetic Compatibility ◽  
Power Level ◽  
Pseudorandom Sequence ◽  
Radio Communication ◽  
Electronic Warfare ◽  
Radio Communications ◽  
Pulse Interference ◽  
Radio Communication System

The article presents the results of the analysis of the existing method of radio suppression of radio communication systems in Wi-Fi networks, and conclusions are drawn regarding ways to increase its effectiveness. The method of radio suppression of radio communication systems with noise-like signals was chosen. It contains the implementation of structural obstacles and a scheme for smooth control of their power implemented in the HTTP/3 protocol. This makes it possible to increase the effectiveness of a jamming station with radio suppression of certain radio communication systems and reduce radioelectronic control equipment requirements. For the applied implementation of this technique in a jamming station, it is necessary to predict a reconnaissance tool covering the reception, determination and estimation of the parameters of noise-like signals; structural interference block; unit execution and regulation of the required power level of structural interference. One of the main tasks is to suppress radio communication systems (SRS). However, with the advance of digital technologies in speech and data transmission, noise-signaling (SHP) signals are increasingly being used to improve the noise immunity and latency of SRHs. One way to implement such signals is to modulate the carrier frequency by a pseudorandom sequence. The issue with productive radio suppression (RP) of SRWs with SHPS has been developing quite actively in recent years, and still remains relevant. Based on the features and means of electronic warfare (EWB), the SPS radio communications systems may be muted by the application of high-power shielding, narrowband or pulse interference. But this method does not cover minimization of radiolabeling of EW methods and can lead to electromagnetic compatibility violations.

Optimal Adaptive Antenna Arrays for Asynchronous Communication Systems

2012 ◽  
Vol 60 (6) ◽  
pp. 3071-3076 ◽  
Author(s):  
Yuri I. Choni ◽  
Ali Hassan
Keyword(s):  
Antenna Arrays ◽  
Communication Systems ◽  
Asynchronous Communication ◽  
Adaptive Antenna ◽  
Adaptive Antenna Arrays

scholarly journals Slotted E-Shaped Meta-Material Decoupling Slab for Densely Packed MIMO Antenna Arrays

Micromachines ◽  
2021 ◽  
Vol 12 (8) ◽  
pp. 873
Author(s):  
Karim H. Moussa ◽  
Ahmed S. I. Amar ◽  
Mohamed Mabrouk ◽  
Heba G. Mohamed
Keyword(s):  
Antenna Arrays ◽  
Communication Systems ◽  
Mutual Coupling ◽  
Spatial Diversity ◽  
Center Frequency ◽  
Wireless Communication Systems ◽  
Mimo Antenna ◽  
Microstrip Patch ◽  
Multiple Input ◽  
Array Gain

In contemporary wireless communication systems, the multiple-input and multiple-output systems are extensively utilized due to their enhanced spectral efficiency and diversity. Densely packed antenna arrays play an important role in such systems to enhance their spatial diversity, array gain, and beam scanning capabilities. In this article, a slotted meta-material decoupling slab (S-MTM-DS) with dual reflexes slotted E-shapes and an inductive stub is proposed. Its function was validated when located between two microstrip patch antenna elements to reduce the inter-element spacing, the mutual coupling, the return losses, and manufacturing costs due to size reduction. A prototype is simply fabricated in a volume of 67.41 × 33.49 × 1.6 mm3 and frequency-span measured from 8.4:11 GHz. At 9.4 GHz frequency, the spaces between the transmitting elements are decreased to 0.57 of the free space wavelength. When the proposed isolation S-MTM-DS is applied, the average isolation among them is measured to be −36 dB, the operational bandwidth is enhanced to be 1.512 GHz, the fractional bandwidth improved to be 16.04%, and the return losses are decreased to be −26.5 dB at 9.4 GHz center frequency. Consequently, the proposed design has the potential to be implemented simply in wireless contemporary communication schemes.

scholarly journals DEVELOPMENT OF PROPOSALS FOR SELECTING AN ENSEMBLE OF BROADBAND SIGNALS SATELLITE COMMUNICATION SYSTEMS WITH MULTI-STATION ACCESS AND CODE DIVISION OF CHANNALS

T-Comm ◽  
2021 ◽  
Vol 15 (4) ◽  
pp. 13-20
Author(s):  
Vladimir I. Filatov ◽  
◽  
Vitaly A. Julego ◽  
Valery U. Balakirev ◽  
Sergey S. Ushakov ◽  
...  
Keyword(s):  
Communication Systems ◽  
Electromagnetic Compatibility ◽  
Satellite Communication ◽  
Spatial Location ◽  
Signal Propagation ◽  
Diagnostic Methods ◽  
Power Flux ◽  
Coverage Area ◽  
Radio Monitoring ◽  
Communication Lines

When designing satellite communication lines and calculating service areas, any unfavorable combinations of signal propagation conditions are taken into account, which, during operation of the repeater, leads to a significant underestimation of the calculated signal level in comparison with the actually provided one. Under these conditions, control of the compliance of the declared characteristics with the real level of the power flux density created by the satellite repeater at the earth’s surface in order to ensure electromagnetic compatibility is the most priority task. When conducting radio monitoring of satellite communication lines using active diagnostic methods, it is necessary to rationally determine the parameters of diagnostic signals so that they meet the conflicting requirements for their confident reception after being relayed by a satellite without disrupting (reducing the capacity) of the functioning of satellite communication lines. Mathematical modeling of the retransmission path of diagnostic signals in the multi-station repeater mode, taking into account the relative spatial location of the satellite, the service area and the radio monitoring station, has been carried out. The model takes into account most of the known factors and features of the propagation of radio signals in satellite communication lines in relation to various statistical phenomena in the atmosphere (refraction, signal depolarization), as well as the instability of the position of the satellite in orbit and the associated variability of the boundaries of the coverage area. As a result of the simulation, it was concluded that under conditions of a priori uncertainty about the polarization parameters used on board the monitored satellite of the antennas, there is a fundamental possibility of active diagnostics of the repeater shafts without weakening the diagnostic signal due to polarization mismatch.

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