Antenna system layout in high capacity geostationary communication satellites

2012 ◽  
Author(s):  
L. S. Lawal ◽  
C.R.R. Chatwin
Keyword(s):  
High Capacity ◽  
Antenna System ◽  
System Layout

scholarly journals Energy Efficient and High Capacity Tradeoff in Distributed Antenna System for a Green Cellular Network

2015 ◽  
Vol 2015 ◽  
pp. 1-9 ◽  
Author(s):  
Mehran Behjati ◽  
Mohammed H. Alsharif ◽  
Rosdiadee Nordin ◽  
Mahamod Ismail
Keyword(s):  
Energy Savings ◽  
High Capacity ◽  
Power Saving ◽  
Path Loss ◽  
Network Capacity ◽  
Antenna System ◽  
Small Scale ◽  
Sleep Mode ◽  
Distributed Antenna System ◽  
Distributed Antenna

Two main concerns for designing a wireless system are more network capacity and less energy consumption. Recently, distributed antenna system (DAS) has received considerable attention due to its potential to provide higher spectral efficiency (SE) and uniform coverage for cellular networks. In this regard, this paper compares the performance of DAS with centralized antenna system (CAS) in LTE-A system in terms of energy efficiency (EE), where practical restrictions such as out-of-cell interference, path loss, and small scale fading are taken into account. Furthermore, the EE and system power consumption are investigated under three different cell-load scenarios (high, moderate, and low load) where different numbers of antennas are activated and remaining of antennas are under sleep mode. Finally, based on the tradeoff between power-saving and EE, two optimal DAS antenna deployments are proposed for low and moderate cell-load scenarios. The results reveal that DAS considerably outperforms CAS in terms of EE and by optimal deploying antennas of DAS significant power-saving and EE are achievable. The proposed methodology achieved savings of up to 27.63% in terms of energy savings in a macrocell with guarantee of a high capacity of data.

scholarly journals Achievable Capacity with Spatial Channel Correlation in Massive MIMO Multi-Cell Systems

2020 ◽  
Vol 9 (4) ◽  
pp. 15-20
Keyword(s):  
Large Scale ◽  
High Capacity ◽  
Antenna System ◽  
Base Station ◽  
Spatial Multiplexing ◽  
Channel Correlation ◽  
Mimo Antenna ◽  
Linearly Independent ◽  
Base Station Antennas ◽  
The Impact

Massive Multi-Input and Multi-Output (MIMO) antenna system provides unlimited capacity by the spatial multiplexing and array gain. Since the data rate has been limited by the coherence interference due to pilot contamination (PC). In this paper, we propose transmit combine and precoding schemes to achieve asymptotic capacity in multi-cell scenario, when the number of base station antennas tends to infinity. The impact of spatial channel correlation on channel capacity is explored by considering the co-variance matrices of the user –terminals (UT)s .To do this, we presented linear processing schemes such as MMSE,MRC, and ZF.Where MMSE achieves high capacity in the presence of large-scale fading and PC. Since the diagonals of the channel covariance matrices were designed with non- zero Eigen values and linearly independent. The results outperform and obtain asymptotic limit, when the co-variance of UTs are linearly independent. The results were simulated by using MATLAB 2018b.

scholarly journals Towards an Efficient Chipless RFID System for Modern Applications in IoT Networks

2021 ◽  
Vol 11 (19) ◽  
pp. 8948
Author(s):  
Wazie M. Abdulkawi ◽  
N. Nizam-Uddin ◽  
Abdel Fattah A. Sheta ◽  
Ibrahim Elshafiey ◽  
Abdullah M. Al-Shaalan
Keyword(s):  
High Capacity ◽  
High Gain ◽  
Antenna System ◽  
Ultra Wideband ◽  
Rfid Tag ◽  
Rectangular Patch ◽  
System A ◽  
Rfid System ◽  
Chipless Rfid ◽  
Performance Validation

In this article, we present the design and validation of an efficient chipless RFID system. A multi-resonator chipless tag is designed and tested for high bit coding capacity. A high gain, ultra-wideband step-shape rectangular patch (USRP) antenna is proposed to validate the specificity of the tag in terms of its operation. The devised antenna is evaluated for various performance parameters, which recommend its suitability for testing and validation of high-capacity tags that can be deployed in modern applications, particularly in the Internet of Things (IoT) networks. A measurement setup is established to achieve performance validation of the tag over a significant range of 40 cm. There is close agreement between the measured and simulated results, which suggests that the proposed antenna system can be adopted in a similar measurement setup to test and validate the performance of any chipless RFID tag operating in the same bandwidth meant for IoT networks.

CuS2 sheets: a hidden anode material with a high capacity for sodium-ion batteries

2021 ◽  
Author(s):  
Shaohua Lu ◽  
Weidong Hu ◽  
Xiaojun Hu
Keyword(s):  
Lithium Ion Batteries ◽  
Anode Material ◽  
Low Cost ◽  
High Capacity ◽  
Lithium Ion ◽  
Sodium Ion ◽  
Sodium Ion Batteries

Due to their low cost and improved safety compared to lithium-ion batteries, sodium-ion batteries have attracted worldwide attention in recent decades.

Receptor Mediated Binding of the Fibrinolytic Components, Plasminogen and Urokinase, to Peripheral Blood Cells

1987 ◽  
Vol 58 (03) ◽  
pp. 936-942 ◽  
Author(s):  
Lindsey A Miles ◽  
Edward F Plow
Keyword(s):  
T Cells ◽  
B Cell ◽  
Peripheral Blood ◽  
Binding Sites ◽  
Blood Cells ◽  
High Capacity ◽  
Red Cells ◽  
Peripheral Blood Cells ◽  
Cellular Functions ◽  
Fibrinolytic Proteins

SummaryGlu-plasminogen binds to platelets; the monocytoid line, U937, and the human fetal fibroblast line, GM1380 bind both plasminogen and its activator, urokinase. This study assesses the interaction of these fibrinolytic proteins with circulating human blood cells. Plasminogen bound minimally to red cells but bound saturably and reversibly to monocytes, granulocytes and lymphocytes with apparent Kd values of 0.9-1.4 μM. The interactions were of high capacity with 1.6 to 49 × 105 sites/cell and involved the lysine binding sites of plasminogen. Both T cells and non-rosetting lymphocytes and two B cell lines saturably bound plasminogen. Urokinase bound saturably to gianulocytes, monocytes, non-rosetting lymphocytes and a B cell line, but minimally to T cells, platelets and red cells. Therefore, plasminogen binding sites of high capacity, of similar affinities, and with common recognition specificities are expressed by many peripheral blood cells. Urokinase receptors are also widely distributed, but less so than plasminogen binding sites. The binding ol plasminogen and/ or urokinase to these cells may lead to generation of cell- associated proteolytic activity which contributes to a variety of cellular functions.

Abnormal Platelet Serotonin Uptake and Binding Sites in Myeloproliferative Disorders

1984 ◽  
Vol 51 (03) ◽  
pp. 349-353 ◽  
Author(s):  
C Caranobe ◽  
P Sié ◽  
F Fernandez ◽  
J Pris ◽  
S Moatti ◽  
...  
Keyword(s):  
Binding Sites ◽  
High Capacity ◽  
Specific Inhibitor ◽  
Myeloproliferative Disorders ◽  
Normal Subjects ◽  
Binding Data ◽  
Full Explanation ◽  
Number Of Binding Sites ◽  
5 Ht Uptake ◽  
Kinetics Of

SummaryA simultaneous investigation of the kinetics of serotonin (5 HT) uptake and of binding sites was carried out in the platelets of normal subjects and of 10 patients affected with various types of myeloproliferative disorders (MD). The 5 HT uptake was analysed according to the Lineweaver-Burk and the Eadie-Hofstee methods. With the two methods, the patient’s platelets exhibited a dramatic reduction of the Vi max and of the Km; in some patients the Eadie-Hofstee analysis revealed that a passive diffusion phenomenon is superimposed on the active 5 HT uptake at least for the higher concentration used. The binding data were analysed with the Scatchard method. Two classes of binding sites (high affinity - low capacity, low affinity - high capacity) were found in normal subjects and patients. Pharmacological studies with imipramine, a specific inhibitor of 5 HT uptake, suggested that both the sites are involved in 5 HT uptake. The number of both binding sites was significantly decreased in patient’s platelets while the affinity constants of these binding sites were not significantly reduced in comparison with those of the control subjects. No correlations were found between Vi max, Km and the number of binding sites. These results suggest that a reduction in the number of platelet membrane acceptors for 5 HT commonly occurs in myeloproliferative disorders but does not provide a full explanation of the uptake defect.

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