scholarly journals Mitigating tropospheric propagation delay errors in precise airborne GPS navigation

2002 ◽  
Author(s):  
J.P. Collins ◽  
R.B. Langley
Keyword(s):  
Propagation Delay ◽  
Tropospheric Propagation ◽  
Gps Navigation

The Design of GPS Digital IF Signal Simulator

2012 ◽  
Vol 490-495 ◽  
pp. 1631-1635
Author(s):  
Bei Zhang
Keyword(s):  
Carrier Phase ◽  
Sampling Rate ◽  
Intermediate Frequency ◽  
Propagation Delay ◽  
Ionospheric Model ◽  
Research Development ◽  
Matlab Simulation ◽  
Gps Navigation ◽  
Matlab Implementation ◽  
Gps System

This paper focuses on the study of digital IF signal simulator's Matlab implementation on the basis of GPS system and GPS navigation signal simulator.It includes the simulator's parameter settings (such as the sampling rate,intermediate frequency), then calculates the sampling signal's code phase and carrier phase by determining the signal's propagation delay. In addition,it introduces and simulates the ionospheric model and the tropospheric model,and corrects the sampling signal's code phase and carrier phase.This paper realizes GPS digital IF signal simulator's Matlab simulation,thus it provides the supporting platform for research,development and testing of the GPS receiver's new algorithm

Materials Issues and Characterization of Low-k Dielectric Materials

MRS Bulletin ◽  
1997 ◽  
Vol 22 (10) ◽  
pp. 49-54 ◽  
Author(s):  
E. Todd Ryan ◽  
Andrew J. McKerrow ◽  
Jihperng Leu ◽  
Paul S. Ho
Keyword(s):  
Process Integration ◽  
Dielectric Materials ◽  
Propagation Delay ◽  
Thermomechanical Properties ◽  
General Criterion ◽  
Crosstalk Noise ◽  
Total Delay ◽  
Interlayer Dielectrics ◽  
Performance Improvements ◽  
And Performance

Continuing improvement in device density and performance has significantly affected the dimensions and complexity of the wiring structure for on-chip interconnects. These enhancements have led to a reduction in the wiring pitch and an increase in the number of wiring levels to fulfill demands for density and performance improvements. As device dimensions shrink to less than 0.25 μm, the propagation delay, crosstalk noise, and power dissipation due to resistance-capacitance (RC) coupling become significant. Accordingly the interconnect delay now constitutes a major fraction of the total delay limiting the overall chip performance. Equally important is the processing complexity due to an increase in the number of wiring levels. This inevitably drives cost up by lowering the manufacturing yield due to an increase in defects and processing complexity.To address these problems, new materials for use as metal lines and interlayer dielectrics (ILDs) and alternative architectures have surfaced to replace the current Al(Cu)/SiO2 interconnect technology. These alternative architectures will require the introduction of low-dielectric-constant k materials as the interlayer dielectrics and/or low-resistivity conductors such as copper. The electrical and thermomechanical properties of SiO2 are ideal for ILD applications, and a change to material with different properties has important process-integration implications. To facilitate the choice of an alternative ILD, it is necessary to establish general criterion for evaluating thin-film properties of candidate low-k materials, which can be later correlated with process-integration problems.

Low-Dielectric-Constant Materials for ULSI Interlayer-Dielectric Applications

MRS Bulletin ◽  
1997 ◽  
Vol 22 (10) ◽  
pp. 19-27 ◽  
Author(s):  
Wei William Lee ◽  
Paul S. Ho
Keyword(s):  
Packing Density ◽  
Propagation Delay ◽  
Single Chip ◽  
Crosstalk Noise ◽  
Metal Line ◽  
Total Delay ◽  
Interlayer Dielectric ◽  
Low Dielectric ◽  
Interconnect Delay ◽  
Interconnect Technology

Continuing improvement of microprocessor performance historically involves a decrease in the device size. This allows greater device speed, an increase in device packing density, and an increase in the number of functions that can reside on a single chip. However higher packing density requires a much larger increase in the number of interconnects. This has led to an increase in the number of wiring levels and a reduction in the wiring pitch (sum of the metal line width and the spacing between the metal lines) to increase the wiring density. The problem with this approach is that—as device dimensions shrink to less than 0.25 μm (transistor gate length)—propagation delay, crosstalk noise, and power dissipation due to resistance-capacitance (RC) coupling become significant due to increased wiring capacitance, especially interline capacitance between the metal lines on the same metal level. The smaller line dimensions increase the resistivity (R) of the metal lines, and the narrower interline spacing increases the capacitance (C) between the lines. Thus although the speed of the device will increase as the feature size decreases, the interconnect delay becomes the major fraction of the total delay and limits improvement in device performance.To address these problems, new materials for use as metal lines and interlayer dielectrics (ILD) as well as alternative architectures have been proposed to replace the current Al(Cu) and SiO2 interconnect technology.

Updated Efficient Area -Carry Select Adder for Low Complexity D LATCH Configuration by disease identification in brain tumor hyper spectral image

2019 ◽  
Vol 14 ◽  
Author(s):  
Teresa V.V ◽  
Anand. B
Keyword(s):  
Research Work ◽  
Low Complexity ◽  
Propagation Delay ◽  
Maximum Speed ◽  
Hyper Spectral ◽  
Ripple Carry Adder ◽  
Minimum Power Consumption ◽  
Carry Select Adder ◽  
The Look ◽  
Propagation Result

Objective: In this research work presents an efficient way Carry Select Adder (CSLA) performance and estimation. The CSLA is utilized in several system to mitigate the issue of carry propagation delay that is happens by severally generating various carries and to get the sum, select a carry because of the uses of various pairs of RCA to provide the sum of the partial section also carry by consisting carry input but the CSLA isn't time economical, then by the multiplexers extreme total and carry is chosen in the selected section. Methodology: The fundamental plan of this work is to attain maximum speed and minimum power consumption by using Binary to Excess-1. Convertor rather than RCA within the regular CSLA. Here RCA denotes the Ripple Carry Adder section. At the span to more cut back the facility consumption, a method of CSLA with D LATCH is implemented during this research work. The look of Updated Efficient Area -Carry Select Adder (UEA-CSLA) is evaluated and intended in XILINX ISE design suite 14. 5 tools. This VLSI arrangement is utilized in picture preparing application by concluding the cerebrum tumor discovery. Conclusion: In this study, medicinal pictures estimation, investigation districts in the multi phantom picture isn't that much proficient to defeat this disadvantage here utilized hyper spectral picture method is presented a sifting procedure in VLSI innovation restriction of cerebrum tumor is performed Updated Efficient Area - Carry Select Adder propagation result dependent on Matrix Laboratory in the adaptation of R2018b.

Brief review on PE method application to propagation channel modeling in sea environment

2012 ◽  
Vol 2 (1) ◽  
Author(s):  
Irina Sirkova
Keyword(s):  
Wave Propagation ◽  
Fourier Transform ◽  
Parabolic Equation ◽  
Initial Conditions ◽  
Channel Modeling ◽  
Radio Propagation ◽  
Propagation Channel ◽  
Tropospheric Propagation ◽  
Propagation Modeling ◽  
Wave Propagation Modeling

AbstractThis work provides an introduction to one of the most widely used advanced methods for wave propagation modeling, the Parabolic Equation (PE) method, with emphasis on its application to tropospheric radio propagation in coastal and maritime regions. The assumptions of the derivation, the advantages and drawbacks of the PE, the numerical methods for solving it, and the boundary and initial conditions for its application to the tropospheric propagation problem are briefly discussed. More details are given for the split-step Fourier-transform (SSF) solution of the PE. The environmental input to the PE, the methods for tropospheric refractivity profiling, their accuracy, limitations, and the average refractivity modeling are also summarized. The reported results illustrate the application of finite element (FE) based and SSF-based solutions of the PE for one of the most difficult to treat propagation mechanisms, yet of great significance for the performance of radars and communications links working in coastal and maritime zones — the tropospheric ducting mechanism. Recent achievements, some unresolved issues and ongoing developments related to further improvements of the PE method application to the propagation channel modeling in sea environment are highlighted.

scholarly journals Rethinking GPS navigation: creating cognitive maps through auditory clues

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Gregory D. Clemenson ◽  
Antonella Maselli ◽  
Alexander J. Fiannaca ◽  
Amos Miller ◽  
Mar Gonzalez-Franco
Keyword(s):  
Everyday Life ◽  
Brain Aging ◽  
Spatial Navigation ◽  
Cognitive Maps ◽  
Active Role ◽  
Alternative Form ◽  
Space Technology ◽  
Gps Navigation ◽  
Spatial Understanding ◽  
The Way

AbstractGPS navigation is commonplace in everyday life. While it has the capacity to make our lives easier, it is often used to automate functions that were once exclusively performed by our brain. Staying mentally active is key to healthy brain aging. Therefore, is GPS navigation causing more harm than good? Here we demonstrate that traditional turn-by-turn navigation promotes passive spatial navigation and ultimately, poor spatial learning of the surrounding environment. We propose an alternative form of GPS navigation based on sensory augmentation, that has the potential to fundamentally alter the way we navigate with GPS. By implementing a 3D spatial audio system similar to an auditory compass, users are directed towards their destination without explicit directions. Rather than being led passively through verbal directions, users are encouraged to take an active role in their own spatial navigation, leading to more accurate cognitive maps of space. Technology will always play a significant role in everyday life; however, it is important that we actively engage with the world around us. By simply rethinking the way we interact with GPS navigation, we can engage users in their own spatial navigation, leading to a better spatial understanding of the explored environment.

scholarly journals Investigating Master–Slave Architecture for Underwater Wireless Sensor Network

Sensors ◽  
2021 ◽  
Vol 21 (9) ◽  
pp. 3000
Author(s):  
Sadeeq Jan ◽  
Eiad Yafi ◽  
Abdul Hafeez ◽  
Hamza Waheed Khatana ◽  
Sajid Hussain ◽  
...  
Keyword(s):  
Wireless Sensor Network ◽  
Sensor Network ◽  
Propagation Delay ◽  
Data Packet ◽  
Wireless Sensor ◽  
Delivery Ratio ◽  
Term Survival ◽  
Limited Bandwidth ◽  
Delay Tolerant

A significant increase has been observed in the use of Underwater Wireless Sensor Networks (UWSNs) over the last few decades. However, there exist several associated challenges with UWSNs, mainly due to the nodes’ mobility, increased propagation delay, limited bandwidth, packet duplication, void holes, and Doppler/multi-path effects. To address these challenges, we propose a protocol named “An Efficient Routing Protocol based on Master–Slave Architecture for Underwater Wireless Sensor Network (ERPMSA-UWSN)” that significantly contributes to optimizing energy consumption and data packet’s long-term survival. We adopt an innovative approach based on the master–slave architecture, which results in limiting the forwarders of the data packet by restricting the transmission through master nodes only. In this protocol, we suppress nodes from data packet reception except the master nodes. We perform extensive simulation and demonstrate that our proposed protocol is delay-tolerant and energy-efficient. We achieve an improvement of 13% on energy tax and 4.8% on Packet Delivery Ratio (PDR), over the state-of-the-art protocol.

scholarly journals Packet Flow Based Reinforcement Learning MAC Protocol for Underwater Acoustic Sensor Networks

Sensors ◽  
2021 ◽  
Vol 21 (7) ◽  
pp. 2284
Author(s):  
Ibrahim B. Alhassan ◽  
Paul D. Mitchell
Keyword(s):  
Sensor Networks ◽  
Mac Protocol ◽  
Propagation Delay ◽  
Basic Function ◽  
Acoustic Sensor ◽  
Underwater Acoustic Sensor Networks ◽  
Medium Access ◽  
Underwater Acoustic ◽  
Q Learning ◽  
Acoustic Sensor Networks

Medium access control (MAC) is one of the key requirements in underwater acoustic sensor networks (UASNs). For a MAC protocol to provide its basic function of efficient sharing of channel access, the highly dynamic underwater environment demands MAC protocols to be adaptive as well. Q-learning is one of the promising techniques employed in intelligent MAC protocol solutions, however, due to the long propagation delay, the performance of this approach is severely limited by reliance on an explicit reward signal to function. In this paper, we propose a restructured and a modified two stage Q-learning process to extract an implicit reward signal for a novel MAC protocol: Packet flow ALOHA with Q-learning (ALOHA-QUPAF). Based on a simulated pipeline monitoring chain network, results show that the protocol outperforms both ALOHA-Q and framed ALOHA by at least 13% and 148% in all simulated scenarios, respectively.

scholarly journals Effective Data Transmission and Control Based on Social Communication in Social Opportunistic Complex Networks

Complexity ◽  
2020 ◽  
Vol 2020 ◽  
pp. 1-20 ◽  
Author(s):  
Weiyu Yang ◽  
Jia Wu ◽  
Jingwen Luo
Keyword(s):  
Complex Networks ◽  
Information Transmission ◽  
Interference Cancellation ◽  
Propagation Delay ◽  
Transmission Efficiency ◽  
Successive Interference Cancellation ◽  
Time Slice ◽  
Signal Interference ◽  
Time Signal ◽  
Interference Avoidance

In opportunistic complex networks, information transmission between nodes is inevitable through broadcast. The purpose of broadcasting is to distribute data from source nodes to all nodes in the network. In opportunistic complex networks, it is mainly used for routing discovery and releasing important notifications. However, when a large number of nodes in the opportunistic complex networks are transmitting information at the same time, signal interference will inevitably occur. Therefore, we propose a low-latency broadcast algorithm for opportunistic complex networks based on successive interference cancellation techniques to improve propagation delay. With this kind of algorithm, when the social network is broadcasting, this algorithm analyzes whether the conditions for successive interference cancellation are satisfied between the broadcast links on the assigned transmission time slice. If the conditions are met, they are scheduled at the same time slice, and interference avoidance scheduling is performed when conditions are not met. Through comparison experiments with other classic algorithms of opportunistic complex networks, this method has outstanding performance in reducing energy consumption and improving information transmission efficiency.

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