scholarly journals Required signal-to-noise ratios, RF signal power, and bandwith for multichannel radio communications systems

1967 ◽  
Author(s):  
E F Florman
2018 ◽  
Vol 7 (2.5) ◽  
pp. 15
Author(s):  
Zuhanis Mansor ◽  
Muhammad Khairulanwar bin Zulkafli

The initial deployments of antenna in the handset consist of fixed non-rotated antenna for transmitting and receiving the signal in the wireless communication scenario. However, link correlation at the UE shows very bad performance when the handset rotates in landscape position. This paper evaluates the impact of accelerometer on the downlink propagation channel of 3G smartphone for non-line-of-sight links. The performance average received signal power is studied for user equipment. Results show that the exploitation of an accelerometer provide better performance in terms of received signal power when the handset rotated from portrait to landscape position. It can be concluded that the deployment of accelerometer can be used to improve existing 3G smartphone received signal. Results also indicate that accelerometer can be used to improve downlink throughput since the signal-to-noise-power is increased by approximately 16%.


Frequenz ◽  
2016 ◽  
Vol 70 (7-8) ◽  
Author(s):  
Thomas Haustein ◽  
Slawomir Stanczak ◽  
Adam Wolisz ◽  
Friedrich Jondral ◽  
Hans Schotten ◽  
...  

AbstractWireless radio communications systems form the basis for mobile network connections in the digital society. A limited amount of radio spectrum and a spatially densified use of wireless communications systems require a resource-efficient use of the spectrum. Mechanisms of cognitive radio may hold the key to a more efficient use of the available spectrum under consideration of quality of service requirements. These mechanisms take advantage of location-specific knowledge of the wireless channel occupation in the dimensions of frequency, time, location and direction in space and therefore enable co-existent and reliable wireless communication. The authors give an introduction to the status of cognitive wireless communication technology, which represents the starting point of a series of research projects promoted by BMBF during 2012–2014.


Author(s):  
V. V. Ovsyanikov ◽  
O. L. Makarov ◽  
O. L. Ol'shevs'kiy ◽  
G. V. Petrenko ◽  
V. M. Popel' ◽  
...  

Author(s):  
B. T. P. Madhav ◽  
G. Jyothsna Devi ◽  
T. Anilkumar

This article presents a MIMO compact antenna measuring 45×45×1.6 mm, on the FR4 substrate, proposed for Ka band and 5G communication applications. The proposed design is suitable to overcome the issues connected with massive MIMO. It has four-sigma-shaped radiating elements and a c-shaped ground plane with coplanar waveguide feeding. Its compact dimensions suit it for most existing communications systems. The aerial operates in the 21–30 GHz range, which covers Ka and 5G communication bands. The proposed antenna exhibits the average efficiency of more than 76% within its operating band and gives a minimum signal to noise plus interference ratio. The presented antenna covers several services, such as Ka band satellite downlink applications and future 5G communication applications.


2018 ◽  
Vol 30 (3) ◽  
pp. 536-543 ◽  
Author(s):  
Stojce Dimov Ilcev

This paper provides an historical review of maritime mobile radio communications systems as a primary means of ensuring the safety and security of ships at sea. Safety at sea has always been a priority for seamen and shippers. Distress alerts at sea caused by the blind forces of Mother Nature or, more commonly, by human factors have occurred over many centuries, as seafarers often set sail with inadequate information about their course, navigation and weather conditions. Until the late nineteenth century, only audio and visual transfers of information from point to point were used. From then on, however, new methods, such as news and information via wire and then by radio communications systems, were introduced. So long as safety standards are met, it is also important to test innovations and technology transfer to develop devices that are more reliable than mobile radio communications.


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