scholarly journals Design and Implementation of the MIMO–COOK Scheme Using an Image Sensor for Long-Range Communication

Sensors ◽  
2020 ◽  
Vol 20 (8) ◽  
pp. 2258 ◽  
Author(s):  
Van Hoa Nguyen ◽  
Minh Duc Thieu ◽  
Huy Nguyen ◽  
Yeong Min Jang
Keyword(s):  
Visible Light ◽  
Radio Frequency ◽  
Human Health ◽  
Error Rate ◽  
Channel Coding ◽  
Matched Filter ◽  
Focal Length ◽  
Satellite Communications ◽  
Image Sensor ◽  
Communication Distance

Radio-frequency technologies are widely applied in many fields such as mobile systems, healthcare systems, television and radio broadcasting, and satellite communications. However, one major problem in wireless communication based on radio frequencies is its impact on human health. High frequencies adversely impact human health more than low frequencies if the signal power transgresses the permissible threshold. Therefore, researchers are investigating the use of visible light waves (instead of the radio-frequency band) for data transmission in three major areas: visible light communication, light fidelity, and optical camera communication. In this paper, we propose a scheme that upgrades the camera on–off keying (COOK) scheme by using it with the multiple-input multiple-output (MIMO) scheme; COOK has been recommended by the IEEE 802.15.7-2018 standard. By applying technologies, such as matched filter, region of interest, and MIMO, our proposed scheme promises to improve the performance of the conventional scheme by improving the data rate, communication distance, and bit error rate. By controlling the exposure time, the focal length in a single camera and using channel coding, our proposed scheme can achieve the communication distance of up to 20 m, with a low error rate.

scholarly journals Performance Analysis and Improvement of Optical Camera Communication

2018 ◽  
Vol 8 (12) ◽  
pp. 2527 ◽  
Author(s):  
Moh. Khalid Hasan ◽  
Mostafa Zaman Chowdhury ◽  
Md. Shahjalal ◽  
Van Thang Nguyen ◽  
Yeong Min Jang
Keyword(s):  
User Satisfaction ◽  
High Performance ◽  
Focal Length ◽  
Sampling Rate ◽  
Image Sensor ◽  
Edge Length ◽  
Data Rate ◽  
Principal Factors ◽  
Communication Distance ◽  
Optical Camera Communication

Optical camera communication (OCC) is a technology in which a camera image sensor is employed to receive data bits sent from a light source. OCC has attracted a lot of research interest in the area of mobile optical wireless communication due to the popularity of smartphones with embedded cameras. Moreover, OCC offers high-performance characteristics, including an excellent signal-to-interference-plus-noise ratio (SINR), high security, low interference, and high stability with respect to varying communication distances. Despite these advantages, OCC suffers from several limitations, the primary of which is the low data rate. In this paper, we provide a comprehensive analysis of the parameters that influence the OCC performance. These parameters include the camera sampling rate, the exposure time, the focal length, the pixel edge length, the transmitter configurations, and the optical flickering rate. In particular, the focus is on enhancing the data rate, SINR, and communication distance, which are the principal factors determining the quality of service experienced by a user. The paper also provides a short survey of modulation schemes used in OCC on the basis of the achieved data rate, communication distance, and possible application scenarios. A theoretical analysis of user satisfaction using OCC is also rendered. Furthermore, we present the simulation results demonstrating OCC performance with respect to variations in the parameters mentioned above, which include the outage probability analysis for OCC.

scholarly journals Design and Implementation of 2D MIMO-Based Optical Camera Communication Using a Light-Emitting Diode Array for Long-Range Monitoring System

Sensors ◽  
2021 ◽  
Vol 21 (9) ◽  
pp. 3023
Author(s):  
Huy Nguyen ◽  
Vanhoa Nguyen ◽  
Conghoan Nguyen ◽  
Van Bui ◽  
Yeongmin Jang
Keyword(s):  
Wireless Communication ◽  
Visible Light ◽  
Channel Coding ◽  
Communication Systems ◽  
Light Emitting Diode ◽  
Focal Length ◽  
Modulation Scheme ◽  
Light Emitting ◽  
Led Array ◽  
Optical Camera Communication

Wireless technologies that use radio frequency (RF) waveforms are common in wireless communication systems, such as the mobile communication, satellite system, and Internet of Things (IoT) systems. It is more advantageous than wired communication because of the ease of installation. However, it can negatively impact human health if high frequencies are used to transmit data. Therefore, researchers are exploring the potential of optical wireless communication as an alternative, which uses the visible light bandwidth instead of RF waveforms. Three possibilities are being investigated: visible light communication, light fidelity, and optical camera communication. In this paper, we propose a multiple-input multiple-output modulation scheme using a light-emitting diode (LED) array, which is applicable to the IoT system, based on on–off keying modulation in the time domain. This scheme is compatible with the two popular types of camera in the market, rolling shutter cameras and global shutter cameras, as well as the closed-circuit television camera, which is used in factories, buildings, etc. Despite the small size of the LED array, implementing this scheme with 10 links in different positions at a communication distance of 20 m is possible for efficient performance (low error rate) by controlling the exposure time, shutter speed, focal length, channel coding and applying the matched filter.

scholarly journals Research on Secure Debugging Interaction of Sensor Nodes Based on Visible Light Communication

Sensors ◽  
2021 ◽  
Vol 21 (3) ◽  
pp. 953 ◽  
Author(s):  
Yuanchu Yin ◽  
Jiefan Qiu ◽  
Zhiqiang Li ◽  
Mingsheng Cao
Keyword(s):  
Visible Light ◽  
Channel Coding ◽  
Sensor Node ◽  
Source Coding ◽  
Visible Light Communication ◽  
Propagation Characteristic ◽  
Transmission Efficiency ◽  
Sensor Nodes ◽  
Pulse Interval ◽  
Inaccessible Area

When a wireless sensor node’s wireless communication fails after being deployed in an inaccessible area, the lost node cannot be repaired through a debugging interaction that relies on that communication. Visible light communication (VLC) as a supplement of radio wave communication can improve the transmission security at the physical layer due to its unidirectional propagation characteristic. Therefore, we implemented a VLC-based hybrid communication debugging system (HCDS) based on VLC using smartphone and sensor node. For the system’s downlink, the smartphone is taken as the VLC gateway and sends the debugging codes to the sensor node by the flashlight. To improve the transmission efficiency of the downlink, we also propose a new coding method for source coding and channel coding, respectively. For the source coding, we analyze the binary instructions and compress the operands using bitmask techniques. The average compression rate of the binary structure reaches 84.11%. For the channel coding, we optimize dual-header pulse interval (DH-PIM) and propose overlapped DH-PIM (ODH-PIM) by introducing a flashlight half-on state. The flashlight half-on state can improve the representation capability of individual symbols. For the uplink of HCDS, we use the onboard LED of the sensor node to transmit feedback debugging information to the smartphone. At the same time, we design a novel encoding format of DH-PIM to optimize uplink transmission. Experimental results show that the optimized uplink transmission time and BER are reduced by 10.71% and 22%, compared with the original DH-PIM.

An approach to ensure joint illumination & communication performance of a forward error corrected indoor visible light communication (VLC) system in presence of ambient light interference

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Sourish Chatterjee ◽  
Biswanath Roy
Keyword(s):  
Visible Light ◽  
Bit Error Rate ◽  
Error Rate ◽  
Light Emitting Diode ◽  
Visible Light Communication ◽  
Ambient Light ◽  
Ambient Illumination ◽  
Communication Performance ◽  
Light Interference ◽  
Forward Error

AbstractIn recent time of looming radio frequency (RF) spectrum crisis, visible light communication using lighting infrastructure emerged as a potential alternative at an indoor environment. This paper addresses the setback associated with ambient light interference in an indoor Visible Light Communication (VLC) system to ensure joint communication and illumination performance inside an office room. A novel VLC architecture with suitable white light emitting diode (WLED) luminaire arrangement is presented to minimize the dispersion of signal to interference plus noise ratio (SINR) across the room. Luminaires are categorized in two groups viz. data transmitting illuminants and illuminants for lighting purpose. The first group is dedicated to transmit data as well as serves the purpose of illumination. The other set creates only ambient illumination to achieve quality lighting attributes. The proposed forward error corrected receiver configuration discards the ambient light noise originated by the illuminants that serve the ambient illumination. Tail biting convolutional encoder and viterbi decoder are used at the encoding section of the transmitter and decoding section of the receiver respectively to improve bit error rate. Results obtained through MATLAB simulation shows better average bit error rate (BER) in the order of 10−8 measured at uniformly distributed 25 grid points over the working plane. At the same time achieved average horizontal illuminance with good uniformity comply with ISO recommendation.

scholarly journals Efficient Exploitation of Radio Frequency and Visible Light Communication Bands for D2D in Mobile Networks

IEEE Access ◽  
2019 ◽  
Vol 7 ◽  
pp. 168922-168933 ◽  
Author(s):  
Mehyar Najla ◽  
Pavel Mach ◽  
Zdenek Becvar ◽  
Petr Chvojka ◽  
Stanislav Zvanovec
Keyword(s):  
Visible Light ◽  
Radio Frequency ◽  
Mobile Networks ◽  
Visible Light Communication

High-speed, high-precision focal length measurement using double-hole mask and advanced image sensor software

2018 ◽  
Vol 74 ◽  
pp. 239-244
Author(s):  
Binh Xuan Cao ◽  
Phuong Le Hoang ◽  
Sanghoon Ahn ◽  
Jeng-o Kim ◽  
Heeshin Kang ◽  
...  
Keyword(s):  
High Precision ◽  
High Speed ◽  
Focal Length ◽  
Image Sensor ◽  
Length Measurement
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