scholarly journals An OFDM Receiver with Frequency Domain Diversity Combined Impulsive Noise Canceller for Underwater Network

2015 ◽  
Vol 2015 ◽  
pp. 1-10 ◽  
Author(s):  
Rie Saotome ◽  
Tran Minh Hai ◽  
Yasuto Matsuda ◽  
Taisaku Suzuki ◽  
Tomohisa Wada
Keyword(s):  
Frequency Domain ◽  
Communication System ◽  
Information Exchange ◽  
Communication Systems ◽  
High Performance ◽  
Autonomous Underwater Vehicle ◽  
Impulsive Noise ◽  
Distribution Data ◽  
Underwater Communication ◽  
Communication Performance

In order to explore marine natural resources using remote robotic sensor or to enable rapid information exchange between ROV (remotely operated vehicles), AUV (autonomous underwater vehicle), divers, and ships, ultrasonic underwater communication systems are used. However, if the communication system is applied to rich living creature marine environment such as shallow sea, it suffers from generated Impulsive Noise so-called Shrimp Noise, which is randomly generated in time domain and seriously degrades communication performance in underwater acoustic network. With the purpose of supporting high performance underwater communication, a robust digital communication method for Impulsive Noise environments is necessary. In this paper, we propose OFDM ultrasonic communication system with diversity receiver. The main feature of the receiver is a newly proposed Frequency Domain Diversity Combined Impulsive Noise Canceller. The OFDM receiver utilizes 20–28 KHz ultrasonic channel and subcarrier spacing of 46.875 Hz (MODE3) and 93.750 Hz (MODE2) OFDM modulations. In addition, the paper shows Impulsive Noise distribution data measured at a fishing port in Okinawa and at a barge in Shizuoka prefectures and then proposed diversity OFDM transceivers architecture and experimental results are described. By the proposed Impulsive Noise Canceller, frame bit error rate has been decreased by 20–30%.

Frequency-domain channel estimation for nonlinear multicarrier underwater communication systems

2010 ◽  
Author(s):  
Ching-Hsiang Tseng ◽  
Chin-Feng Lin ◽  
Fu-Sheng Lu ◽  
Hsien-Sen Hung ◽  
Tzong-Dar Wu ◽  
...  
Keyword(s):  
Channel Estimation ◽  
Frequency Domain ◽  
Communication Systems ◽  
Underwater Communication

scholarly journals PERFORMANCE EVALUATION OF SINGLE CARRIER FREQUENCY DOMAIN EQUILIZER (SC-FDE) OVER IMPULSIVE NOISE CHANNEL

2019 ◽  
Vol 11 (2) ◽  
pp. 270-277
Author(s):  
Hussein Abdullah Leftah ◽  
Husham Lateef Swadi
Keyword(s):  
Frequency Domain ◽  
Carrier Frequency ◽  
Communication Systems ◽  
Impulsive Noise ◽  
Signal To Noise Ratio ◽  
High Signal ◽  
Signal To Noise ◽  
Single Carrier ◽  
Noise Ratio ◽  
Error Floors

Impulsive noise is considered as one of the major source of disturbance in the state-of-the-art multicarrier (MC) communication systems. Therefore, several techniques are being constantly proposed to eliminate the effect of such noise. In this work, a time domain matrix interleaved is compiled with a single carrier frequency domain equalizer (SC-FDE) is proposed to reduce the deleterious effects of impulsive noise. A mathematical model for the proposed scheme is also presented in this paper. Simulation results show that the proposed technique superiors the interleaved multicarrier system where the proposed scheme can completely avoid the error floors not only at high signal-to-noise ratio (SNR) but also at heavily distributed impulsive noise. The bit-error-rate (BER) of the alternative proposed scheme decreases as the signal-to-noise ratio (SNR) increases whereas the BER of the standard system suffers from error-floors with a constant BER at about 10-3 for about 8 dB SNR for medium and heavily impulsive noise.

scholarly journals Designing laser beams carrying OAM for a high-performance underwater communication system

2020 ◽  
Vol 37 (5) ◽  
pp. 876 ◽  
Author(s):  
Svetlana Avramov-Zamurovic ◽  
Abbie T. Watnik ◽  
James R. Lindle ◽  
K. Peter Judd
Keyword(s):  
Communication System ◽  
High Performance ◽  
Laser Beams ◽  
Underwater Communication

scholarly journals A novel cooperative spectrum signal detection algorithm for underwater communication system

2019 ◽  
Vol 2019 (1) ◽  
Author(s):  
Jiang Xiaolin ◽  
Tang Zhengyu ◽  
Wang Ronghui
Keyword(s):  
Compressed Sensing ◽  
Communication System ◽  
Dirichlet Process ◽  
Bayesian Model ◽  
Communication Systems ◽  
Cooperative Spectrum Sensing ◽  
Sampling Rate ◽  
Utilization Rate ◽  
Underwater Communication ◽  
Automatic Grouping

Abstract In order to further improve the spectrum resource detection probability and increase the spectrum utilization rate in underwater wireless communication systems, this paper designs a novel multi-layer cooperative spectrum sensing algorithm based on compressed sensing, which uses compressed sensing technology to estimate the spectrum to reduce the sampling rate and the overhead of sonar signals. This new algorithm seeks the optimal hyper-parameter through Bayesian model. The multi-layer Bayesian model is introduced into the Dirichlet process to realize the automatic grouping of compressed perceptual data with the information from the non-parametric grouping mechanism, and the optimal super-parameters are selected through the fusion center to determine the spectrum. Simulation results show that the proposed algorithm fully considers the temporal correlation of compressed perceptual data and effectively improves spectral sensing performance of underwater communication system.

Study on underwater wireless communication system using LED

2015 ◽  
Vol 29 (06n07) ◽  
pp. 1540023 ◽  
Author(s):  
Hyun-Joong Son ◽  
Hyeung-Sik Choi ◽  
Ngoc-Huy Tran ◽  
Ji-Hoon Ha ◽  
Dae-Hyeung Ji ◽  
...  
Keyword(s):  
Communication System ◽  
Sea Water ◽  
Fresnel Lens ◽  
Underwater Communication ◽  
Communication Performance ◽  
Led Light ◽  
Communication Device ◽  
Performance Results ◽  
Variable Focus ◽  
Underwater Wireless Communication

In this paper, a new variable-focus LED light device is developed for underwater communication. Usually used as an underwater lighting fixture, the LED light device in this study is utilized as an underwater communication device (UCD) by controlling the distance between light source and lens when communication is needed. A transmission and a receiving part of LED light for communication using photoelectric sensor and Fresnel lens are also developed. The communication system was tested in fresh water and sea water to verify its communication performance; results of which are presented in this study.

scholarly journals Using Fast Frequency Hopping Technique to Improve Reliability of Underwater Communication System

2020 ◽  
Vol 10 (3) ◽  
pp. 1172 ◽  
Author(s):  
Jan H. Schmidt
Keyword(s):  
Acoustic Wave ◽  
Data Transmission ◽  
Communication System ◽  
Doppler Effect ◽  
Communication Systems ◽  
Frequency Hopping ◽  
Reliable Data ◽  
Underwater Communication ◽  
Fast Frequency Hopping ◽  
The Doppler Effect

Acoustic underwater communication systems designed to work reliably in shallow coastal waters must overcome major limitations such as multipath propagation and the Doppler effect. These restrictions are the reason for the complexity of receivers being built, whose task is to decode a symbol on the basis of the received signal. Additional complications are caused by the low propagation speed of the acoustic wave in the water and the relatively narrow bandwidth. Despite the continuous development of communication systems using coherent modulations, they are still not as reliable as is desirable for reliable data transmission applications. This article presents an acoustic underwater communication system that uses one of the varieties of the spread spectrum technique i.e., the fast frequency hopping technique (FFH). This technique takes advantage of binary frequency-shift keying (BFSK) with an incoherent detection method to ensure the implementation of a system whose main priority is reliable data transmission and secondary priority is the transmission rate. The compromised choice of parameters consisted of the selection between the narrow band of the hydroacoustic transducer and the maximum number of carrier frequency hops, which results from the need to take into account the effects of the Doppler effect. In turn, the number of hops and the symbol duration were selected adequately for the occurrence of multipath propagations of an acoustic wave. In addition, this article describes experimental communication tests carried out using a laboratory model of the FFH-BFSK data transmission system in the shallow water environment of Lake Wdzydze/Poland. The test results obtained for three channels of different lengths are discussed.

Synthezis the strucrure of cloud computing system to control of mobile robots group

2016 ◽  
Vol 11 (1) ◽  
pp. 72-80
Author(s):  
O.V. Darintsev ◽  
A.B. Migranov
Keyword(s):  
Cloud Computing ◽  
Mobile Robots ◽  
Distinctive Feature ◽  
Information Exchange ◽  
High Performance ◽  
Computing System ◽  
Control Information ◽  
Cloud Computing System ◽  
Group Control ◽  
Reliability And Robustness

In article one of possible approaches to synthezis of group control of mobile robots which is based on use of cloud computing is considered. Distinctive feature of the offered techniques is adequate reflection of specifics of a scope and the robots of tasks solved by group in architecture of control-information systems, methods of the organization of information exchange, etc. The approach offered by authors allows to increase reliability and robustness of collectives of robots, to lower requirements to airborne computers when saving summary high performance in general.

Fault Tree Analysis for a Modern Communication System

2017 ◽  
Vol 7 (1) ◽  
Author(s):  
Kamal Hamid ◽  
Nadim Chahine
Keyword(s):  
Communication System ◽  
Communication Systems ◽  
Fault Tree ◽  
Fault Tree Analysis ◽  
Theory And Practice ◽  
Tree Analysis ◽  
Satisfactory Performance ◽  
System Components ◽  
Link Budget ◽  
Simulation Results

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%.

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