Propagation modeling and performance analysis of intelligent drilling communication system based on capacitance coupling approach

SIMULATION ◽  
2017 ◽  
Vol 94 (5) ◽  
pp. 421-431 ◽  
Author(s):  
Feng Liu ◽  
Yajun Liu ◽  
Debin Yang ◽  
Jinwu Xu

A new type of intelligent drilling communication system is proposed based on capacitance coupling in order to realize signal transmission in the downhole environment. A system model is established and the dispersion equation is derived. Group velocity, propagation constant, attenuation factor, and the terminal matching condition of the system are discussed according to theoretical derivations. Simulations of a large number of drill pipe units in the time domain, based on the fourth-order Runge–Kutta method, are described to verify the mathematical derivations. An experimental system of lumped parameter components has been established, which verifies the effectiveness of the simulation. Analytical and simulation results show that the carrier frequency can be as high as 0.843 MHz, and that the bandwidth of the proposed system can reach up to about 406 kHz. The results can provide a theoretical basis and comprehensive design guidance for the frequency, communication rate, and bandwidth budget of intelligent drilling communication systems.

Author(s):  
Nikoaj Kushnir ◽  
Anatoly Semenko ◽  
Georgij Kosovan ◽  
Natalija Bokla ◽  
Yevhen Shestopal

In telecommunications, a particular place belongs to systems with a wideband noise-free signal, the undisputed advantage of which is increased by both narrowband and wideband interference, confidentiality of information transmission, as well as electromagnetic compatibility with adjacent electronic devices. A wideband noise-free signal is formed using a number of known modulated sequences - m-, Kasam-, Gold sequences, typically by direct spreading.Systems using known pseudo-random sequences cannot be considered protected from unauthorized access.An effective way to increase the confidentiality of signal transmission in a noise-free TSC is to use a chaotic signal-based PVP.Pseudorandom sequence generators are based on one-dimensional chaotic reflections such as logistics, quadratic, and cubic. Researches have shown the undeniable advantage of logistical reflection. The construction of hidden communication systems using the deterministic chaos phenomenon is progressive issue nowadays. Several main stages should be carried out for achieving the goal. These are providing of the stability degree of synchronization between the drive and response generators of the transmitter and receiver respectively, investigation of chaotic oscillation to estimate the noise similarity and hardware design of communication system. It is known that the stable synchronization mode is needed for the quality level of data recovery. Therefore the basic conditions were computed for unidirectional coupled chaotic generators for the purpose of providing of generalized synchronization. To construct the communication system with high hiding degree first of all it is necessary to select the chaotic carrier signal the spectral and statistical characteristics of which were similar to noise. Using the obtained results the hardware prototype of hidden communication system was constructed


2017 ◽  
Vol 39 (1) ◽  
Author(s):  
Florence Rashidi ◽  
Jing He ◽  
Lin Chen

AbstractThe challenge in the free-space optical (FSO) communication is the propagation of optical signal through different atmospheric conditions such as rain, snow and fog. In this paper, an orthogonal frequency-division multiplexing technique (OFDM) is proposed in the FSO communication system. Meanwhile, considering the rain attenuation models based on Marshal & Palmer and Carbonneau models, the performance of FSO communication system based on the OFDM is evaluated under the heavy-rain condition in Changsha, China. The simulation results show that, under a heavy-rainfall condition of 106.18 mm/h, with an attenuation factor of 7 dB/km based on the Marshal & Palmer model, the bit rate of 2.5 and 4.0 Gbps data can be transmitted over the FSO channels of 1.6 and 1.3 km, respectively, and the bit error rate of less than 1E − 4 can be achieved. In addition, the effect on rain attenuation over the FSO communication system based on the Marshal & Palmer model is less than that of the Carbonneau model.


Author(s):  
Nikolaj Kushnir ◽  
Anatoly Semenko ◽  
Georgij Kosovan ◽  
Natalija Bokla ◽  
Yevhen Shestopal

In telecommunications, a particular place belongs to systems with a wideband noise-free signal, the undisputed advantage of which is increased by both narrowband and wideband interference, confidentiality of information transmission, as well as electromagnetic compatibility with adjacent electronic devices. A wideband noise-free signal is formed using a number of known modulated sequences - m-, Kasam-, Gold sequences, typically by direct spreading.Systems using known pseudo-random sequences cannot be considered protected from unauthorized access.An effective way to increase the confidentiality of signal transmission in a noise-free TSC is to use a chaotic signal-based PVP.Pseudorandom sequence generators are based on one-dimensional chaotic reflections such as logistics, quadratic, and cubic. Researches have shown the undeniable advantage of logistical reflection. The construction of hidden communication systems using the deterministic chaos phenomenon is progressive issue nowadays. Several main stages should be carried out for achieving the goal. These are providing of the stability degree of synchronization between the drive and response generators of the transmitter and receiver respectively, investigation of chaotic oscillation to estimate the noise similarity and hardware design of communication system. It is known that the stable synchronization mode is needed for the quality level of data recovery. Therefore the basic conditions were computed for unidirectional coupled chaotic generators for the purpose of providing of generalized synchronization. To construct the communication system with high hiding degree first of all it is necessary to select the chaotic carrier signal the spectral and statistical characteristics of which were similar to noise. Using the obtained results the hardware prototype of hidden communication system was constructed


Author(s):  
Muhammad Arif Bin Jalil

Abstract: Optical fiber is a medium that made by silica or plastic, and widely used in transmitting information over longer distance especially in communication system. There are three types of fiber optic used in this project which are single mode stepindex (SMSI), multimode step-index (MMSI), and multimode graded-index (MMGI) in optical communication system. There are three objectives in this project in order to get the suitable optical fibers in the communication system. First objective is to simulate the result by using Excel and Origin software. The data and the formula of fiber optics will be key in through Excel software while the graph will be analyzed by using Origin software. The second objective is to compare the different types of fiber optics in communication system by comparing the several of their characteristics such as numerical aperture (NA), acceptance angle (θ(a)) and propagation constant (β). The performance of all types fiber optics are analyzed from the result using the standard communication wavelength of 1550 nm. The core diameter for SMSI, MMSI, and MMGI are 9, 200 and 50 μm respectively while the cladding diameter for SMSI and MMGI is 125 μm and 240 μm for MMSI. This diameter also been analyzed by using the standard value for optical communication system. Then, the comparison between SMSI, MMSI and MMGI will be made to choose the more suitable for optical communication system based on their characteristics. From the results, MMSI and MMGI give best performance compared to SMSI. After that, the third objective is to make the comparison between MMSI and MMGI in term of intermodal dispersion to compare the efficiencies of fiber optics. MMGI give the better result in terms of efficiencies for communication system compared to MMSI. Keyword: Single Mode Step-Index (SMSI), Multimode Step-Index (MMSI), Multimode Graded-Index (MMGI), Communication System, Excel and Origin Software


Author(s):  
Kamal Hamid ◽  
Nadim Chahine

Wireless communications became one of the most widespread means for transferring information. Speed and reliability in transferring the piece of information are considered one of the most important requirements in communication systems in general. Moreover, Quality and reliability in any system are considered the most important criterion of the efficiency of this system in doing the task it is designed to do and its ability for satisfactory performance for a certain period of time, Therefore, we need fault tree analysis in these systems in order to determine how to detect an error or defect when happening in communication system and what are the possibilities that make this error happens. This research deals with studying TETRA system components, studying the physical layer in theory and practice, as well as studying fault tree analysis in this system, and later benefit from this study in proposing improvements to the structure of the system, which led to improve gain in Link Budget. A simulation and test have been done using MATLAB, where simulation results have shown that the built fault tree is able to detect the system’s work by 82.4%.


2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Iztok Dogsa ◽  
Mihael Spacapan ◽  
Anna Dragoš ◽  
Tjaša Danevčič ◽  
Žiga Pandur ◽  
...  

AbstractBacterial quorum sensing (QS) is based on signal molecules (SM), which increase in concentration with cell density. At critical SM concentration, a variety of adaptive genes sharply change their expression from basic level to maximum level. In general, this sharp transition, a hallmark of true QS, requires an SM dependent positive feedback loop, where SM enhances its own production. Some communication systems, like the peptide SM-based ComQXPA communication system of Bacillus subtilis, do not have this feedback loop and we do not understand how and if the sharp transition in gene expression is achieved. Based on experiments and mathematical modeling, we observed that the SM peptide ComX encodes the information about cell density, specific cell growth rate, and even oxygen concentration, which ensure power-law increase in SM production. This enables together with the cooperative response to SM (ComX) a sharp transition in gene expression level and this without the SM dependent feedback loop. Due to its ultra-sensitive nature, the ComQXPA can operate at SM concentrations that are 100–1000 times lower than typically found in other QS systems, thereby substantially reducing the total metabolic cost of otherwise expensive ComX peptide.


Biosensors ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 65
Author(s):  
Puneet Manocha ◽  
Gitanjali Chandwani

Molecular communication is a bioinspired communication that enables macro-scale, micro-scale and nano-scale devices to communicate with each other. The molecular communication system is prone to severe signal attenuation, dispersion and delay, which leads to performance degradation as the distance between two communicating devices increases. To mitigate these challenges, relays are used to establish reliable communication in microfluidic channels. Relay assisted molecular communication systems can also enable interconnection among various entities of the lab-on-chip for sharing information. Various relaying schemes have been proposed for reliable molecular communication systems, most of which lack practical feasibility. Thus, it is essential to design and develop relays that can be practically incorporated into the microfluidic channel. This paper presents a novel design of passive in-line relay for molecular communication system that can be easily embedded in the microfluidic channel and operate without external energy. Results show that geometric modification in the microfluidic channel can act as a relay and restore the degraded signal up-to 28%.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Weilong Wang ◽  
Kiyoshi Tamaki ◽  
Marcos Curty

AbstractMeasurement-device-independent quantum key distribution (MDI-QKD) can remove all detection side-channels from quantum communication systems. The security proofs require, however, that certain assumptions on the sources are satisfied. This includes, for instance, the requirement that there is no information leakage from the transmitters of the senders, which unfortunately is very difficult to guarantee in practice. In this paper we relax this unrealistic assumption by presenting a general formalism to prove the security of MDI-QKD with leaky sources. With this formalism, we analyze the finite-key security of two prominent MDI-QKD schemes—a symmetric three-intensity decoy-state MDI-QKD protocol and a four-intensity decoy-state MDI-QKD protocol—and determine their robustness against information leakage from both the intensity modulator and the phase modulator of the transmitters. Our work shows that MDI-QKD is feasible within a reasonable time frame of signal transmission given that the sources are sufficiently isolated. Thus, it provides an essential reference for experimentalists to ensure the security of implementations of MDI-QKD in the presence of information leakage.


2017 ◽  
Vol 7 (1.1) ◽  
pp. 696
Author(s):  
Satyanarayana P ◽  
Charishma Devi. V ◽  
Sowjanya P ◽  
Satish Babu ◽  
N Syam Kumar ◽  
...  

Machine learning (ML) has been broadly connected to the upper layers of communication systems for different purposes, for example, arrangement of cognitive radio and communication network. Nevertheless, its application to the physical layer is hindered by complex channel conditions and constrained learning capacity of regular ML algorithms. Deep learning (DL) has been as of late connected for some fields, for example, computer vision and normal dialect preparing, given its expressive limit and advantageous enhancement ability. This paper describes about a novel use of DL for the physical layer. By deciphering a communication system as an auto encoder, we build up an essential better approach to consider communication system outline as a conclusion to-end reproduction undertaking that tries to together enhance transmitter and receiver in a solitary procedure. This DL based technique demonstrates promising execution change than traditional communication system.  


2015 ◽  
Vol 740 ◽  
pp. 819-822
Author(s):  
Qing Shen ◽  
Tian Tian Guo ◽  
Yao Zhi Du

Device-to-Device (D2D) communication allows user devices in proximity to directly communicate with each other through reusing resources in cellular communication system. D2D improves the system capacity while it also raises some challenges on interference. This paper adopts reconfigurable antenna in D2D communication generating directional signal transmission between D2D pairs which mitigates the interference to other users. The simulations show that such scheme improve the system capacity compared to the traditional one.


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