scholarly journals Reduced-Complexity Radio Architectures for Enhanced Receive Selection Combining in Multiuser Diversity Systems

2012 ◽  
Vol 2012 ◽  
pp. 1-10 ◽  
Author(s):  
Elpiniki P. Tsakalaki ◽  
Osama N. Alrabadi ◽  
Constantinos B. Papadias ◽  
Ramjee Prasad
Keyword(s):  
Antenna Selection ◽  
Low Cost ◽  
Spatial Diversity ◽  
Antenna System ◽  
Multiuser Diversity ◽  
Selection Combining ◽  
User Terminal ◽  
Receive Diversity ◽  
Diversity Systems ◽  
System Properties

Although antenna selection is a simple and efficient technique for enhancing the downlink performance of multiuser diversity systems, the large antenna interelement spacing required for achieving spatial diversity is prohibitive for user terminals due to size restrictions. In order to allay this problem, we propose miniaturized switched beam receiver designs assisted by low-cost passive reflectors. Unlike conventional spatial receive diversity systems, the proposed angular diversity architectures occupy a small volume whereas the antenna system properties are optimized by controlling the strong reactive fields present at small dimensions. The systems are designed for maximum antenna efficiency and low interbeam correlation, thus yieldingNpractically uncorrelated receive diversity branches. The simulation results show that the proposed enhanced diversity combining systems improve the average throughput of a multiuser network outperforming classical antenna selection especially for small user populations and compact user terminal size.

scholarly journals Loading Algorithm for Multicarrier Spatial Diversity Systems with Antenna Selection

2007 ◽  
Vol 6 (6) ◽  
pp. 2060-2065
Author(s):  
Alexander Wyglinski ◽  
Fabrice Labeau ◽  
Peter Kabal
Keyword(s):  
Antenna Selection ◽  
Spatial Diversity ◽  
Diversity Systems

scholarly journals Organ-specific, multimodal, wireless optoelectronics for high-throughput phenotyping of peripheral neural pathways

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Woo Seok Kim ◽  
Sungcheol Hong ◽  
Milenka Gamero ◽  
Vivekanand Jeevakumar ◽  
Clay M. Smithhart ◽  
...  
Keyword(s):  
High Throughput ◽  
Low Cost ◽  
Optoelectronic Device ◽  
Antenna System ◽  
Neural Pathways ◽  
Organ Specific ◽  
Coil Antenna ◽  
Sensory Fibers

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.

scholarly journals Study of the Readability of Passive UHF RFID Tags Placed Inside a Cargo Van by a Reader Located Outside

2014 ◽  
Vol 10 (2) ◽  
pp. 76
Author(s):  
Philippe Mariage ◽  
M.M. Handeme Nguema ◽  
Laurent Clavier
Keyword(s):  
Low Cost ◽  
Software Tool ◽  
Antenna System ◽  
Uhf Rfid ◽  
Passive Uhf Rfid ◽  
Passive Tags ◽  
Whole Space ◽  
Storage Area ◽  
Semi Empirical ◽  
Theoretical Results

The aim of this paper is to study the feasibility of getting information from a cargo van returning back on its storage area by using a low cost communication system. According to the low speed of the vehicle and to the involved short distances, a UHF RFID solution is considered. An experimental study shows that passive tags may be read successfully but not in the entire space of the van. A semi-empirical numerical method based on the Geometrical Optics is derived in order to build a fast computer aided-positioning tool that may help to optimize the location of the tags. The same software tool is used for carrying out a parametric study that informs on the best antenna system to use. It is find out that a solution using passive tags and two antennas limits the theoretical results to 90% successful reading percentage whereas using semi-passive tags ensures a 100% one in the whole space of the vehicle.

scholarly journals Massive MIMO: Achievable Energy Efficiency for 5G systems with Multi-user Environment

2019 ◽  
Vol 8 (2) ◽  
pp. 6527-6534
Keyword(s):  
Energy Efficiency ◽  
Power Consumption ◽  
Path Loss ◽  
Antenna System ◽  
Base Station ◽  
Small Cells ◽  
Limiting Factors ◽  
Improve Energy Efficiency ◽  
User Terminal ◽  
Simulation Results

Massive Multi-Input and Multi-Output (MIMO) antenna system potentially provides a promising solution to improve energy efficiency (EE) for 5G wireless systems. The aim of this paper is to enhance EE and its limiting factors are explored. The maximum EE of 48 Mbit/Joule was achieved with 15 user terminal (UT)s. This problem is related to the uplink spectral efficiency with upper bound for future wireless networks. The maximal EE is obtained by optimizing a number of base station (BS) antennas, pilot reuse factor, and BSs density. We presented a power consumption model by deriving Shannon capacity calculations with closed-form expressions. The simulation result highlights the EE maximization with optimizing variables of circuit power consumption, hardware impairments, and path-loss exponent. Small cells achieve high EE and saturate to a constant value with BSs density. The MRC scheme achieves maximum EE of 36 Mbit/Joule with 12 UTs. The simulation results show that peak EE is obtained by deploying massive BS antennas, where the interference and pilot contamination are mitigated by coherent processing. The simulation results were implemented by using MATLAB 2018b.

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