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Underwater Wireless Control and Transmission System Based on GSM Short Message
Abstract
Because of the hostile seawater channel condition, underwater wireless communication becomes the bottleneck of the communication interlinking stations on sea, land and air all the while. In this paper, GSM short Message Service is applied to the underwater wireless control and data transmission. Using our underwater modem designed to overcome the effect of the hostile ocean channel, we can control the underwater device and receive data by sending short message. In order to mitigate the signal fading and inter-symbol interference (ISI) resulting from the multi-path effect (MPE), techniques of frequency hopping and frequency diversity are applied to the underwater acoustic communication. The experimental results show satisfactory performance.
Underwater wireless power transfer (UWPT) is a critical infrastructure for supplying power to underwater devices such as underwater sensors and autonomous underwater vehicles (AUVs). Enabling a software-defined architecture for UWPT promises to build a flexible and programmable underwater energy network. Though it is crucial that UWPT be made more resilient to cyber attacks and energy stealing, this remains an open challenge. In this paper, we propose a software-defined UWPT (SD-UWPT) system that is both cyber and energy secure. A moving target defense approach (MTD) and an active synchronous detection (ASD) method are developed to protect the SD-UWPT against scanning-based attacks and power bot attacks. To enable energy-secure UWPT, an impedance measurement based approach (IMBA) is further established to prevent energy stealing. Through comprehensive evaluations, we validate the benefits of SD-UWPT and demonstrate the effectiveness of the proposed cyber-energy secure strategies against various attacks.
A state-of-the-art literature review of underwater acoustic models
developed by the Navy sonar modeling community is presented. Three types
of acoustic models are addressed: propagation loss, noise, and active
sonar/reverberation models. Basic features of each type of model and
areas of application are discussed. Problems associated with model
evaluation and validation are described.
Introduction. Acoustical Oceanography. Propagation I. Observations and Physical Models. Propagation II. Mathematical Models (Part One). Propagation II. Mathematical Models (Part Two). Noise I. Observations and Physical Models. Noise II. Mathematical Models. Reverberation I. Observations and Physical Models. Reverberation II. Observations and Physical Models. Sonar Performance Models. Model Evaluation. Simulation.
Because of the hostile ocean transmission condition, underwater acoustic communication technology is one of the most difficulty communication technology. Frequency-Hopping underwater acoustic communication system is drawing more and more attention for its good performance under serious noise and multi-path interference condition. Synchronization signal processing is a key factor of FH underwater acoustic communication system. In the research of FH shallow underwater acoustic data communication system, a synchronization method employing adaptive line-spectrum enhancing (ALE) method, frequency diversity, pulse width judgment and frame synchronization signal correlation processing to detect synchronization signal under the condition of low SNR and heavy amplitude fluctuation is presented. The sea experiment results are satisfactory.
Because of the hostile ocean transmission conditions, underwater acoustic communication is one of the most difficulty communication technologies. Frequency-hopping underwater acoustic communication systems are drawing more and more attention for their good performance under serious noise and multipath interference conditions. Synchronization signal processing is a key factor of FH underwater acoustic communication systems. In the FH shallow underwater acoustic data communication system, employing an adaptive line-spectrum enhancing (ALE) method, frequency diversity, pulse width judgment and frame synchronization signal correlation processing to detect the synchronization signal under the condition of low SNR and heavy amplitude fluctuation, satisfactory ocean experimental results are obtained.
The major obstacle to underwater acoustic communication is the
interference of multi-path signals due to surface and bottom
reflections. High speed acoustic transmission over a shallow water
channel characterized by small grazing angles presents formidable
difficulties. The reflection losses associated with such small angles
are low, causing large amplitudes in multi-path signals. In this paper
we propose a simple but effective model for multi-path interference,
which is then used to assess the performance of a digital communication
system operating in a shallow water channel. The results indicate that
transmission rates in excess of 8 kbits/s are possible over a distance
of 13 km and channel depth of only 20 meters. Such a system offers
improved performance in applications such as data collection from
underwater sensors
An underwater acoustic local area network (ALAN) provides
multipoint-to-point telemetry between many high-rate, ocean-bottom
sensors and a central, surface-deployed receiver in the 10-30 kHz
vertical acoustical channel. Ocean-bottom modems initiate the
transmission process by requesting data channel time slots via a common
narrow-band request channel. Request packets overlap in time and
frequency in this channel, and the throughput and average transmission
delay rely heavily on the successful resolution of the request packet
collisions. This paper presents the design, analysis, and experimental
demonstration of a request channel receiver capable of resolving
collisions between several asynchronous and cochannel packets. The
receiver algorithm differs from standard capture schemes (by
demodulating the data from both strong and weak transmitters),
conventional spread-spectrum receivers (by overcoming the near-far
problem), and existing multiple-access demodulation techniques (by
adapting to the number of interfering signals, and the unknown phase,
Doppler, amplitude, and timing of each signal in the collision). The
receiver demodulates the collided packets by decision-directed
techniques through a novel method of estimating the interference for
each user which minimizes error propagation due to inaccurate tentative
decisions. An inwater experiment illustrates that this technique is
extremely desirable for collision resolution in underwater acoustic
local area networks, and also for underwater autonomous vehicles with
both sidescan sonar as well as acoustic telemetry links
Research on the system of underwater wireless control and data transmisstion basing on GSM short messge
- Yuan Fei
Yuan Fei, "Research on the system of underwater wireless control and data transmisstion basing on GSM short messge ", Master.D dissertation, Xiamen university,2005
Underwater Acoustic Image Transmission System Based on DSP
- Cheng En
Cheng En and Xu Ru, "Underwater Acoustic Image Transmission System Based on DSP", Marine science bulletin Eng.,Vol.4(1), pp.27-31, 2002.
Digital Underwater Acoustic Voice Communication with Severe Multipath Eliminated
- Xu Xiangbin
Xu Xiangbin, "Digital Underwater Acoustic Voice Communication with Severe Multipath Eliminated", Ph.D dissertation, Xiamen university, 2003