DOA estimation for low-cost array antenna system based on GROUSE and EM algorithms

Author(s):  
Keita Yamada ◽  
Koichi Ichige
2002 ◽  
Vol 50 (5) ◽  
pp. 641-650 ◽  
Author(s):  
Tae-Yeoul Yun ◽  
Chunlei Wang ◽  
P. Zepeda ◽  
C.T. Rodenbeck ◽  
M.R. Coutant ◽  
...  

Author(s):  
Alexander A. Maltsev ◽  
Valentin M. Seleznev ◽  
Alexander S. Rulkov ◽  
Olesya V. Bolkhovskaya

Introduction. Currently, one of the most promising approaches of the 5th generation mobile wireless systems development is the deployment of heterogeneous networks based on existing LTE cellular systems with large and small cells. The main elements of such networks can be small low cost relay stations equipped with highly directional steerable antenna systems to connect small cells with LTE base station serving macrocell. Objective. Existing solutions are either too expensive or not allowing flexible rearrangement of current information transmission lines. The objective of this work is to develop antenna equipment for low cost relay stations based on simple steerable antenna systems of millimetre wavelength (57-64 GHz), which allow beamsteering in both azimuth and elevation planes. Methods and materials. The developed steerable bifocal lens antenna system is a lens of a special shape made of a high molecular weight polyethylene and integrated with a phased array antenna. A key feature of the designed antenna system is a wide-angle beamsteering in the azimuth plane and ability to adjust the beam in the elevation plane. The calculation of the lens profiles was carried out by means of an approximation of geometrical optics in Matlab, and the main technical characteristics of the lens antenna system were obtained by direct electromagnetic modelling in CST Microwave Studio. Results. The prototype of the steerable bifocal lens-array antenna system is developed and its characteristics are studied. The following technical characteristics are achieved in the 57–64 GHz range: beamsteering in the elevation plane is ±3º, beamsteering in the azimuth plane is ±40º, and antenna gain is from 20 to 27.5 dBi for all angles. Conclusion. It was shown that the developed antenna system can be successfully used as receiving and transmission antenna equipment of small relay stations that transmit information in the frequency range of 57-64 GHz over a distance of 100-300 m.


2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Woo Seok Kim ◽  
Sungcheol Hong ◽  
Milenka Gamero ◽  
Vivekanand Jeevakumar ◽  
Clay M. Smithhart ◽  
...  

AbstractThe vagus nerve supports diverse autonomic functions and behaviors important for health and survival. To understand how specific components of the vagus contribute to behaviors and long-term physiological effects, it is critical to modulate their activity with anatomical specificity in awake, freely behaving conditions using reliable methods. Here, we introduce an organ-specific scalable, multimodal, wireless optoelectronic device for precise and chronic optogenetic manipulations in vivo. When combined with an advanced, coil-antenna system and a multiplexing strategy for powering 8 individual homecages using a single RF transmitter, the proposed wireless telemetry enables low cost, high-throughput, and precise functional mapping of peripheral neural circuits, including long-term behavioral and physiological measurements. Deployment of these technologies reveals an unexpected role for stomach, non-stretch vagal sensory fibers in suppressing appetite and demonstrates the durability of the miniature wireless device inside harsh gastric conditions.


2021 ◽  
Vol 1804 (1) ◽  
pp. 012123
Author(s):  
Nada M. Khalil Al-Ani ◽  
Oras A. Shareef Al-Ani ◽  
Mahmood F. Mosleh ◽  
Read A. Abd-Alhameed

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