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In this paper, design, implementation and analysis of a new underwater multiple input multiple output visible light communication (VLC) system is presented. The VLC system consists of a transmitter, water channel, and a receiver. The transmitter is made out of light emitting diodes (LEDs'), while a camera based architecture is adopted at the receiv...
Citations
... In VLC, Line Of Site (LOS) propagation is dominant [3]. This phenomenon has many applications like indoor positioning, cooperation between vehicles, Hybrid WiFi-VLC for internet access, underwater communication and smart sensor network using light [4][5][6][7][8][9]. IEEE 802.15.7 is the most applicable standard that is introduced for VLC. ...
Visible Light Communication (VLC) is one of the most efficient way of wireless data transmission that has attracted a number of researchers. In this paper, a simplex VLC system standard employing a Digital Signal Processor (DSP) chipset is implemented. This system is compliant with a physical layer regarding IEEE802.15.7 PHY1 modes. It is tried to use low-cost hardware with a suitable performance for short distance VLC communication. Bit Error Rate (BER) performance of 4.462Kb/s and 70.92Kb/s is measured at different distances.
... Simulation results show 10 −6 of BER is achievable for 10 W power consumption with the data rate of 100 Mbps over 110 m. In [17] and [18], MIMO method is applied to UVLC systems using multiple LEDs, but less than 1 m communication links are established with poor performances and very low data rates. The authors in [19] and [20] introduce OFDM to the designed systems. ...
High-speed, reliable, flexible, and cost-effective underwater wireless communication systems have a wide variety of use in scientific, civilian, and commercial domains. Visible Light Communication (VLC) seems to be a promising candidate in satisfying majority of the requirements listed above. From this perspective, VLC could easily be deployed in heterogeneous wireless networking scenarios with high quality of service (QoS). Therefore, in this study, an adapted LTE frame structure is implemented for underwater VLC (UVLC) system. The performance of UVLC system employing ACO-OFDM modulation technique is practically tested by taking channel estimation and synchronization into account. Also, the effects of varying OFDM parameters on the system's signal-to-noise ratio (SNR) and the bit-error-rate (BER) performances are studied. The implementation is tested for QPSK and 16-QAM modulation techniques supporting both 128- and 1024-points FFT configurations which correspond to data rates of 1.92 Mbps and 15.36 Mbps, respectively. Experimental results show that BER could be reduced down to a level on the order of
$10^{-6}$
.
In this paper, we suppose an underwater optical wireless communication (UOWC) system, where the communication utilizes visible light communication for its advantages as wide spectrum, high data rate and high accuracy. The novelty of this paper is focused on improving the channel estimation between transmitter and receiver, where using Kalman Filter (KF) for channel estimation in UOWCs achieves the best results as compared to other traditional channel estimation methods. The scenario of this paper is summarized in transmitting data from transmitter to receiver via underwater harbor and coastal channels. Two channel models are utilized: weighted double gamma functions (WDGF) and a combination of exponential and arbitrary power function (CEAPF). The modulation technique used is optical orthogonal frequency division multiplexing with two kinds: direct current optical orthogonal frequency division multiplexing (DCO-OFDM) and asymmetrically clipping optical orthogonal frequency division multiplexing (ACO-OFDM). Three different techniques are used for channel estimation: Least Square (LS), minimum mean square error (MMSE), and KF. The simulation results reveal that the ACO-OFDM modulation technique with CEAPF channel modeling using KF achieves the lowest bit error rate (BER) compared to other channel estimation methods. The improvement percentage at BER = 10⁻¹ is 13.3% for ACO-OFDM over DCO-OFDM with CEAPF in coastal water and is is 9.3% for WDGF. This indicates that CEAPF performs about 4% better than WDGF for ACO-OFDM than DCO-OFDM in terms of channel estimation.
Visible light can be used to implement an underwater communication link, as an alternative for the current acoustic based communication methods. This paper presents the design and implementation of a unidirectional underwater visible light communication (VLC) system where a camera receiver is used. Specifically, data is transmitted from a submerged system to a floating body. In order to characterize the performance of this system, we first model the channel under zero water turbulence conditions for different transmission distances. Also algorithms and experimental results of detection are discussed. Our results show that, the proposed system can only achieve low data speeds compared to traditional VLC underwater systems, where photo detectors are used at the receiver. However, reasonable bit error rate performance can be achieved using the proposed VLC system design. Hence the proposed system can be developed further and can be used as a successful alternative for acoustic based under water communication systems.
