- 标题
- 摘要
- 关键词
- 实验方案
- 产品
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Analysis of optical injection on red and blue laser diodes for high bit-rate visible light communication
摘要： In this work, self-injection and external-injection in ～450 nm InGaN/GaN blue and ～650 nm InGaP/AlGaInP red diode lasers are investigated. A distinct locking characteristic is observed in the self-injection case with small 19 cm cavity length, demonstrating enhanced ～2.34 and ～2.07 GHz 3-dB bandwidths, corresponding to a factor of ～1.4 and ～1.1 improvement, and reduced ～60 and ～80 pm spectral linewidths, for the blue and the red lasers, respectively. Moreover, this short external cavity self-injection locked system exhibited superior performance by a factor of 1.1–1.3 compared to the long cavity (26 cm) configuration. Conversely, the external optical injection exhibited weak locking signature with improved linewidths by a factor of ～1.6–2.8 and reaching as small as ～70 and ～87 pm for the blue laser, respectively, while almost doubling in the peak powers. Later, on–off keying modulation technique based data transmission rates of up to 3.5 and 4.5 Gb/s are demonstrated on free-running blue and red laser diodes, respectively, employing an in-house laser diode mount based system. Moreover, owing to the bandwidth limitation of the optically injected systems, successful transmission of up to 2 Gb/s is demonstrated with better performance compared to the respective free-running cases, in particular, the external-optically injected system demonstrated more than double improvement in the bit-error-rate.
关键词： Visible light communication,Semiconductor laser diodes,External optical injection,Self-injection locking
更新于2025-11-28 14:23:57
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[Lecture Notes in Computer Science] Distributed Computing and Internet Technology Volume 11319 (15th International Conference, ICDCIT 2019, Bhubaneswar, India, January 10–13, 2019, Proceedings) || Improved Visible Light Communication Using Code Shift Keying Modulation
摘要： Visible light communication can provide higher bandwidth and bit rates without causing any interference to the Radio Frequency signals. Red-Green-Blue Light-Emitting Diodes are more suitable than other light sources as they have a smaller switching time, greater lifespan and cost-effective. Designing a communication scheme that avoids dimming and flickering, and that maximize the throughput and coverage area is challenging. Modulation schemes such as Amplitude Shift Keying, Frequency Shift Keying, and Phase Shift Keying exist in the literature for communication with controlled dimming and flickering effect. However, these schemes may not be efficient as they bound the bit rates with more Bit Error Rate. In this paper, a spread spectrum technique, Code Shift Keying along with Manchester (CSK-M) coding, is used to improve bit rates, a reduction in Bit Error Rate with an efficient control of fluctuations and dimming effect. The simulation results show that the presented approach outperforms the existing modulation schemes.
关键词： Visible light communication,Dimming,Bit rate,BER,CSK-M
更新于2025-09-23 15:23:52
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Visible Light Communication based Vehicle-to-Vehicle Tracking using CMOS Camera
摘要： This study presents a visible light-communication-based vehicle-to-vehicle tracking system using a new positioning algorithm and modified version of the Kalman filter. In this system, LED head and tail lamps on the vehicles are used to transmit positioning signals to other vehicles. Two CMOS dashboard cameras on each vehicle are used to receive these signals. From the geometric relationship between two cameras and the images of LEDs captured by these two cameras, the instantaneous position of the target vehicle can be determined given that at least one LED of the target vehicle is in the view frame of the two cameras. The discrete positioning result always contains unavoidable errors, which consist of systematic errors caused by the CMOS rolling shutter artifact and the weak spatial separability of the sensor, and other random errors. The contribution of this paper is twofold. First, a new positioning algorithm with two compensation mechanisms is proposed to eliminate systematic errors. Second, a modified Kalman filter is proposed to filter out random errors to achieve a smooth and accurate tracking result for the vehicle position. The performance of the system is verified through simulations.
关键词： tracking,vehicle,Kalman filter,visible light communication,camera
更新于2025-09-23 15:23:52
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Optimization of Non-Orthogonal Multiple Access based Visible Light Communication Systems
摘要： In Visible Light Communication (VLC), the data is transmitted by modulating the Light Emitting Diode (LED). The data-rate is throttled by the narrow modulation bandwidth of LEDs which results as a barrier in attaining high transmission rates. Non-Orthogonal Multiple Access (NOMA) is a new Multiple Access (MA) scheme envisioned to improve the system capacity. In addition to MA schemes, optimization techniques are applied to further improve the data-rate. In this letter, convex optimization is applied on NOMA-based VLC system for downlinks. The proposed optimization system is analyzed in terms of the Bit Error Rate (BER) and the sum-rate.
关键词： Sum-rate maximization,Visible Light Communication,Non-Orthogonal Multiple Access (NOMA),Convex Optimization,5G
更新于2025-09-23 15:23:52
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[IEEE 2018 IEEE 3rd Optoelectronics Global Conference (OGC) - Shenzhen (2018.9.4-2018.9.7)] 2018 IEEE 3rd Optoelectronics Global Conference (OGC) - High Speed Novel Hybrid Modulation Technique of Visible Light Communication Based on Artificial Neural Network Equalizer
摘要： Visible light communication (VLC) which realizes data transmission and universal illumination simultaneously has attracted much attention recently. However, the transmission rate of the VLC remains low due to the low bandwidth performance and inter-symbol interference (ISI). Therefore, a hybrid approach using pulse amplitude modulation and pulse width modulation in conjunction with an artificial neural network (ANN) equalizer is proposed, which can theoretically increase the transmission rate by 4 times compared with the traditional way, and provide variable brightness to realize the integration of data transmission and illumination control. In addition, an artificial neural network equalizer is proposed to undo the effects of ISI, considering that the bandwidth of the LED is only 3MHz. Without the ANN equalizer, the maximum transmission rate of the proposed hybrid modulation link only reaches 36 Mbps under the condition of no signal processing; however, with the ANN equalizer, the transmission speed can up to 2.6 Gbps. The proposed system not only achieves a genuine combination of data transmission and control illumination levels, but also realizes a high data rate with less complexity.
关键词： code division multiple access,pulse amplitude modulation,visible light communication,artificial neural network equalizer
更新于2025-09-23 15:23:52
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[IEEE 2018 International Conference on Electrical Engineering and Computer Science (ICECOS) - PANGKAL PINANG, Indonesia (2018.10.2-2018.10.4)] 2018 International Conference on Electrical Engineering and Computer Science (ICECOS) - Design and Implementation of Analog Transceiver Circuit for Patient Monitoring System based on OWC
摘要： In this paper, we present the design and implementation of analog front-end (AFE) module for patient monitoring system based on optical wireless communication (OWC). The communication link uses visible light as a downlink and IR as an uplink communication. The wireless patient monitoring system consists of two parts: host or coordinator and client or patient device. On the patient device part, we designed the PCB with a shield configuration so the AFE module can be connected directly to GPIO’s microcontroller unit (MCU) without any cable. Moreover, the AFE module is attempted to have a similar size with the MCU. Hence, the patient device has a small-size, minimum of wires, wearable, and low-complexity. The AFE receiver output is a digital waveform. Therefore, it is compatible with On-off Keying (OOK) modulation. The AFE module can be switched digitally up to 25 KHz of optical frequency for visible light downlink and 1500 Hz optical frequency for IR uplink. The optical link distance can reach up to 2 meters with 0o of reception angle.
关键词： Visible light communication,Wearable patient monitoring,IR communication,Optical Wireless Communication (OWC),Analog Front-End
更新于2025-09-23 15:22:29
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Simplified Vehicle Vibration Modeling for Image Sensor Communication
摘要： Image sensor communication (ISC), derived from visible light communication (VLC) is an attractive solution for outdoor mobile environments, particularly for intelligent transport systems (ITS). In ITS-ISC, tracking a transmitter in the image plane is critical issue since vehicle vibrations make it difficult to select the correct pixels for data reception. Our goal in this study is to develop a precise tracking method. To accomplish this, vehicle vibration modeling and its parameters estimation, i.e., representative frequencies and their amplitudes for inherent vehicle vibration, and the variance of the Gaussian random process representing road surface irregularity, are required. In this paper, we measured actual vehicle vibration in a driving situation and determined parameters based on the frequency characteristics. Then, we demonstrate that vehicle vibration that induces transmitter displacement in an image plane can be modeled by only Gaussian random processes that represent road surface irregularity when a high frame rate (e.g., 1000 fps) image sensor is used as an ISC receiver. The simplified vehicle vibration model and its parameters are evaluated by numerical analysis and experimental measurement and obtained result shows that the proposed model can reproduce the characteristics of the transmitter displacement sufficiently.
关键词： vehicle motion model,vehicle vibration,visible light communication,image sensor communication,road surface irregularity,transmitter displacement
更新于2025-09-23 15:22:29
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[ACM Press the 16th ACM Conference - Shenzhen, China (2018.11.04-2018.11.07)] Proceedings of the 16th ACM Conference on Embedded Networked Sensor Systems - SenSys '18 - Selective Visible Light Communication for Multiple Video Cameras using a Single Light Source
摘要： In this paper, we propose a selective visible light communication method using a single light source and multiple video cameras by using their differences in reception sensitivity between carrier waves composed of OFDM signals. In our evaluation experiments, the transmitted signals were composed of 50th, 75th, 78th, and 80th order carrier waves encoding symbols modulated by 4, 8, and 16 PSK. The exposure time ratio for each camera was set to different values so that symbols encoded in one of the carrier waves could be decoded successfully, but erroneously in the other waves. The selectivity of individual carrier waves as theoretically derived was confirmed through the experimental results.
关键词： rolling shutter,Visible light communication,selective communication
更新于2025-09-23 15:22:29
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High Speed Wireless Internet Using LiFi
摘要： The internet has become a basic necessity, so with the advancement in technology, people are demanding something faster than WI-FI. Since light is the only medium that can travel fastest than any other source of data transmission else so if we use this medium for internet, it will be the best utilization of medium with a higher data transmission rate. This technology was implemented over and came out with concept of LI-FI Technology. Li-Fi in known for Light-Fidelity, Li-Fi uses an idea of visible light communication (VLC) technology that uses light as a medium to convey fast high-speed communication in a manner like Wi-Fi. Since visible light is present everywhere, the main idea of our review paper is how LI-FI technology can help in security, speed and reliability of internet and even can change our life style. This innovation is actualized utilizing white LED bulbs matched with the Downlink transmitter that can give a higher information transmission rate up to 10Gbps. The main prospective of this paper demonstrates the forthcoming routine of Li-Fi technology innovation and its highlights to expand the execution of information transmission and different applications where Li-Fi has been put to utilize.
关键词： Data utilization,Visible Light communication,Wi-Fi,server,Light-emitting diode (LED),Light-Fidelity (Li-Fi),Video LAN Client (VLC)
更新于2025-09-23 15:22:29
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[IEEE 2018 18th International Symposium on Communications and Information Technologies (ISCIT) - Bangkok, Thailand (2018.9.26-2018.9.29)] 2018 18th International Symposium on Communications and Information Technologies (ISCIT) - Design of Voltage Reference Comparator Circuit for Receiver Circuit in VLC System
摘要： Visible light communication (VLC) system is a wireless communication from light of the light emitting diode (LED). In this work, we design the voltage reference comparator circuit method for the receiver circuit with data communication via white LED. In this experiment, we evaluate the VLC system of the transmitter circuit and receiver circuit by using bits data communication with the distance 50 to 100 cm. We measure the frequency of the white LED signal detection between the transmitter circuit and the receiver circuit, which the frequency uses about 9.615 kHz. This comparator circuit method can be used to refer the voltage signals of the receiver circuit in VLC system.
关键词： Photodiode,Amplify circuit,Light emitting diode,Visible light communication,Comparator circuit
更新于2025-09-23 15:22:29