On the stability of random access with energy harvesting and collision resolution

2014 ◽  
Author(s):  
Ahmed M. Bedewy ◽  
Karim G. Seddik ◽  
Amr A. El-Sherif
Keyword(s):  
Energy Harvesting ◽  
Random Access ◽  
Collision Resolution ◽  
The Stability

In Situ Study of Barrier Layers Using Spectroscopic Ellipsometry and Mass Spectroscopy of Recoiled Ions

2000 ◽  
Vol 619 ◽  
Author(s):  
Y. Gao ◽  
A.H. Mueller ◽  
E.A. Irene ◽  
O. Auciello ◽  
A.R. Krauss ◽  
...  
Keyword(s):  
Real Time ◽  
Mass Spectroscopy ◽  
Spectroscopic Ellipsometry ◽  
Nitrogen Concentration ◽  
Random Access ◽  
Copper Interconnects ◽  
Access Memory ◽  
Barrier Layers ◽  
The Stability

ABSTRACTAn in situ study of barrier layers using spectroscopic ellipsometry (SE) and Time-of-Flight (ToF) mass spectroscopy of recoiled ions (MSRI) is presented. First the formation of copper silicides has been observed by real-time SE and in situ MSRI in annealed Cu/Si samples. Second TaSiN films as barrier layers for copper interconnects were investigated. Failure of the TaSiN layers in Cu/TaSiN/Si samples was detected by real-time SE during annealing and confirmed by in situ MSRI. The effect of nitrogen concentration on TaSiN film performance as a barrier was also examined. The stability of both TiN and TaSiN films as barriers for electrodes for dynamic random access memory (DRAM) devices has been studied. It is shown that a combination of in situ SE and MSRI can be used to monitor the evolution of barrier layers and detect the failure of barriers in real-time.

scholarly journals Channel Length Biasing for Improving Read Margin of the 8T SRAM at Near Threshold Operation

Electronics ◽  
2019 ◽  
Vol 8 (6) ◽  
pp. 611 ◽  
Author(s):  
Ik Joon Chang ◽  
Yesung Kang ◽  
Youngmin Kim
Keyword(s):  
Threshold Voltage ◽  
Supply Voltage ◽  
Random Access ◽  
Channel Length ◽  
Voltage Level ◽  
Exact Data ◽  
Optimum Energy ◽  
The Stability ◽  
20 Nm ◽  
Near Threshold

Reducing a supply voltage in order to minimize power consumption in memory is a major design consideration in this field of study. In static random access memory (SRAM), optimum energy can be achieved by reducing the voltage near the threshold voltage level for near threshold voltage computing (NTC). However, lowering the operational voltage drastically degrades the stability of SRAM. Thus, in conventional 6T SRAM, it is almost impossible to read exact data, even when a small process variation occurs. To address this problem, an 8T SRAM structure is proposed which can be widely used for improving the read stability at lower voltage operation. In this paper, we investigate the channel length biasing effect on the read access transistor of the 8T SRAM in NTC and compare this with 6T SRAM. Read stability can be improved by suppressing the leakage current due to the longer channel length. Simulation results show that, in NTC, up to a 12× read-error reduction can be achieved by the 20 nm channel length biasing in the 8T SRAM compared to 6T SRAM.

scholarly journals Distributed Optimal Random Access Scheme for Energy Harvesting Devices in Satellite Communication Networks

Sensors ◽  
2018 ◽  
Vol 19 (1) ◽  
pp. 99
Author(s):  
Pengxu Li ◽  
Gaofeng Cui ◽  
Weidong Wang
Keyword(s):  
Energy Harvesting ◽  
Communication Networks ◽  
Satellite Communication ◽  
Negative Impact ◽  
Low Cost ◽  
Random Access ◽  
Optimal Solution ◽  
Wireless Channel ◽  
Communication Overhead ◽  
Iteration Algorithm

This paper considers satellite communication networks where each satellite terminal is equipped with energy harvesting (EH) devices to supply energy continuously, and randomly transmits bursty packets to a geostationary satellite over a shared wireless channel. Packet replicas combined with a successive iteration cancellation scheme can reduce the negative impact of packet collisions but consume more energy. Hence, appropriate energy management policies are required to mitigate the adverse effect of energy outages. Although centralized access schemes can provide better performance on the networks’ throughput, they expend extra signallings to allocate the resources, which leads to non-negligible communication latencies, especially for the satellite communication networks. In order to reduce the communication overhead and delay, a distributed random access (RA) scheme considering the energy constraints is studied. Each EH satellite terminal (EH-ST) decides whether to transmit the packet and how many replicas are transmitted according to its local energy and EH rates to maximize the average long-term network throughput. Owing to the nonconvexity of this problem, we adopted a game theoretic method to approximate the optimal solution. By forcing all the EH-STs to employ the same policy, we characterized and proved the existence and uniqueness of the symmetric Nash equilibrium (NE) of the game. Moreover, an efficient algorithm is proposed to calculate the symmetric NE by combining a policy iteration algorithm and the bisection method. The performance of the proposed RA scheme was investigated via numerous simulations. Simulation results showed that the proposed RA scheme is applicable to the EH devices in the future low-cost interactive satellite communication system.

scholarly journals The Design and Optimization of a Wireless Power Transfer System Allowing Random Access for Multiple Loads

Energies ◽  
2019 ◽  
Vol 12 (6) ◽  
pp. 1017 ◽  
Author(s):  
Linlin Tan ◽  
Ming Zhang ◽  
Songcen Wang ◽  
Shulei Pan ◽  
Zhenxing Zhang ◽  
...  
Keyword(s):  
Random Access ◽  
Wireless Power Transfer ◽  
Power Transfer ◽  
Wireless Power ◽  
Design And Optimization ◽  
Highly Sensitive ◽  
In Series ◽  
Overall Efficiency ◽  
Optimizing Control ◽  
The Stability

As is common in multi-load wireless power transfer (WPT) systems based on series–series compensation topology, the power received by loads and the efficiency of the process are highly sensitive to changes in the number of loads. To guarantee that the power supplied to a load remains stable when other loads access or leave the system, we propose an improved multi-load system for WPT. The new system uses an LCC/S topology (based on inductor–capacitor–inductor or LCL topology) to keep the power received by the loads stable. By comparing two scenarios (ideal and real models based on LCC/S topology), we aim to eliminate cross-coupling between receiving coils by connecting compensating capacitors in series on the receiving side. In this way, the stability of the power received by loads is further improved. Moreover, a method of optimizing control over the efficiency is proposed based on the effect on the overall efficiency of impedance and number of loads. This allows us to optimize the overall efficiency of the system. Finally, a system to verify our theoretical analysis is established and used to show the validity and effectiveness of the proposed system.

scholarly journals Random Access Communication for Wireless Control Systems With Energy Harvesting Sensors

2020 ◽  
Vol 68 ◽  
pp. 3961-3975
Author(s):  
Miguel Calvo-Fullana ◽  
Carles Anton-Haro ◽  
Javier Matamoros ◽  
Alejandro Ribeiro
Keyword(s):  
Energy Harvesting ◽  
Control Systems ◽  
Random Access ◽  
Wireless Control
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