- 标题
- 摘要
- 关键词
- 实验方案
- 产品
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Channel modeling and analysis of OWC-massive MIMO systems
摘要： In this paper, we study the difference between the uplink and downlink channels of short-range slant free-space optical wireless between Ground - alpine base stations using massive MIMO linear arrays at both ends. The uplink and downlink atmospheric loss, scintillation, beam spreading and pointing error model of linear array slant range are constructed. The uplink and downlink atmospheric loss, spatial coherence length, receiver beamwidth, pointing error variance, relative mean square error (RMSE) and bit error rate (BER) are compared and analyzed under different distances of different wavelengths of light waves. After simulation analysis, it is concluded that the uplink and downlink atmospheric losses are the same, the uplink receiver beamwidth is larger than the downlink, and the downlink coherence length and the pointing error variance are larger than the uplink, and both monotonously change with the wavelength of the light wave and the propagation distance.
关键词： Optical wireless communication,MSE,Wavelength,Channel modeling,Massive MIMO
更新于2025-09-23 15:23:52
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Error performance of optical wireless communication systems exercising BPSK subcarrier intensity modulation in non-Kolmogorov turbulent atmosphere
摘要： Subcarrier intensity modulation (SIM) scheme is preferred due to efficient bandwidth usage superiority over other modulation techniques such as on–off keying (OOK), pulse position modulation (PPM). In this paper, we investigate the bit error rate (BER) performance of optical wireless communication (OWC) system using binary phase shift keying (BPSK) SIM in non-Kolmogorov turbulent atmosphere. We pay attention to the weak turbulence conditions by using Rytov approximation and considering that the receiver is a PIN photodetector. Propagating beam type is Gaussian. It is seen that BER performance of the BPSK SIM OWC is significantly affected from non-Kolmogorov power law exponent, load resistor, responsivity of the PIN photodetector, bandwidth, beam source size, turbulence strength and noise factor.
关键词： Subcarrier intensity modulation,Optical wireless communication,Bit error rate,Atmospheric turbulence
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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[IEEE 2018 International Conference on Intelligent and Innovative Computing Applications (ICONIC) - Mon Tresor, Plaine Magnien, Mauritius (2018.12.6-2018.12.7)] 2018 International Conference on Intelligent and Innovative Computing Applications (ICONIC) - Development of an IR-based Device for Wireless Communication in Community Health Centres
摘要： With the increase in implementation of advanced communication equipment, especially in the medical sector, finding solutions to anticipated problems has become paramount. Our envisaged problem is the uneasy procedure of taking patients’ variables frequently in community health centers, where there is usually minimal support staff. This paper indicates that human variables such as body temperature and movement at a special ward in a community health care center are transferable from one computer to another. However, our implementation integrated a temperature sensor (LM35), pyroelectric infrared, and infrared to a low-cost Arduino-generic Lilypad microcontroller (as the transmitter). The developed device was able to communicate with the receiver side (comprised of Arduino Mega, infrared receiver, and a computer). We were able to transfer data seamlessly from Mr. C. E. Ngene to a remote computer for analysis. This project will make up for the unavailability of expensive devices and low workforce in the rural community health centers. This designed device can help patients to be attended to quickly as the patients start to have issues.
关键词： sensors,infrared,health,remote monitoring,optical wireless communication
更新于2025-09-23 15:22:29
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Optical Wireless Communication Based Indoor Positioning Algorithms: Performance Optimisation and Mathematical Modelling
摘要： In this paper, the performance of the optimal beam radius indoor positioning (OBRIP) and two-receiver indoor positioning (TRIP) algorithms are analysed by varying system parameters in the presence of an indoor optical wireless channel modelled in line of sight configuration. From all the conducted simulations, the minimum average error value obtained for TRIP is 0.61 m against 0.81 m obtained for OBRIP for room dimensions of 10 m × 10 m × 3 m. In addition, for each simulated condition, TRIP, which uses two receivers, outperforms OBRIP and reduces position estimation error up to 30%. To get a better understanding of error in position estimation for different combinations of beam radius and separation between light emitting diodes, the 90th percentile error is determined using a cumulative distribution frequency (CDF) plot, which gives an error value of 0.94 m for TRIP as compared to 1.20 m obtained for OBRIP. Both algorithms also prove to be robust towards change in receiver tilting angle, thus providing flexibility in the selection of the parameters to adapt to any indoor environment. In addition, in this paper, a mathematical model based on the concept of raw moments is used to confirm the findings of the simulation results for the proposed algorithms. Using this mathematical model, closed-form expressions are derived for standard deviation of uniformly distributed points in an optical wireless communication based indoor positioning system with circular and rectangular beam shapes.
关键词： position estimation,channel modelling,raw moments,optical wireless communication,indoor positioning system,cumulative distribution frequency,standard deviation
更新于2025-09-23 15:22:29
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Hybrid DCO-OFDM, ACO-OFDM and PAM-DMT for Dimmable LiFi
摘要： This paper proposes a hybrid orthogonal frequency division multiplexing (OFDM) modulation termed as hybrid DC-biased asymmetrically-clipped pulse-amplitude-modulated OFDM (HDAP-OFDM) for providing power efficient communication and dimming control for light fidelity (LiFi) schemes. The proposed HDAP-OFDM is a combination of three OFDM formats: DC-biased optical OFDM (DCO-OFDM), asymmetrically clipped optical OFDM (ACO-OFDM) and pulse amplitude modulated discrete multitone (PAM-DMT). In HDAP-OFDM, the lower-index subcarriers carry DCO-OFDM, while the remaining higher subcarriers carry ACO-OFDM on the odd-index subcarriers and PAM-DMT on the even-index subcarriers. Mathematical analysis shows that the required DC bias for HDAP-OFDM is a function of the required dimming levels and the root mean square of the three of its components. Furthermore, an algorithm is presented to simulate the dimming control of HDAP-OFDM. Simulations results indicate that by adjusting the proportion of subcarriers for the three OFDM/DMT elements, HDAP-OFDM can have a wide dimming range, a low peak to average power ratio, and high power efficiency. Results also show that at a bit error rate of 10-3 and a dimming range of 3% to 97%, HDAP-OFDM exhibits 8 dB more optical and electrical power efficiency than existing asymmetrical hybrid optical OFDM.
关键词： HDAP-OFDM,optical wireless communication,DC bias,OFDM,dimming,LiFi
更新于2025-09-23 15:21:21
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Temporal dispersion compensation for turbid underwater optical wireless communication links
摘要： Temporal dispersion compensation has been considered in the turbid underwater optical wireless communication systems. A comprehensive comparison of different equalization criteria and adaptive equalization strategies has been made in this paper. New results have been shown since there is an optimal field of view for certain channels. Moreover, one can also make a tradeoff among computational complexity, performance and transmit distance by referring to the conclusions in this paper.
关键词： underwater optical wireless communication,equalization,Temporal dispersion
更新于2025-09-23 15:21:21
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Dual-Hop Mixed RF-UOW Communication System: A PHY Security Analysis
摘要： In this paper, the secrecy performance of a dual-hop mixed radio-frequency/underwater optical wireless communication (RF-UOWC) system is investigated. The considered system consists of one single antenna source node (S) communicating with one destination node (D), considered as the legitimate receiver, through an amplify-and-forward relay node equipped with multiple antennas for reception. Specifically, the relay receives the incoming signal from S via an RF link, applies maximal-ratio combining technique, amplifies the output combined signal with either a fixed gain or variable gain, and then forwards it to the destination via an UOWC link. The transmission protocol is performed under the eavesdropper’s attempt to overhear the RF link (i.e., S-R). We derive exact closed-form expressions for the system’s average secrecy capacity and the intercept probability in terms of Meijer’s G-function as well as the univariate and bivariate Fox’s H -functions. A complexity analysis is also performed to analyze the evaluation time of the derived analytical formulas as well as Monte Carlo simulation method complexity. Our derived analytical formulas present an efficient tool to depict the impact of some system and channel parameters on the secrecy performance, namely, the number of relay antennas, the number of eavesdropping nodes, relay gain, fading severity of RF links, and water turbulence severity of the UOWC link.
关键词： intercept probability,underwater optical wireless communication (UOWC),dual-hop relaying,physical layer security,performance analysis,Amplify-and-forward,average secrecy capacity
更新于2025-09-23 15:21:01
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[IEEE 2018 Asia Communications and Photonics Conference (ACP) - Hangzhou, China (2018.10.26-2018.10.29)] 2018 Asia Communications and Photonics Conference (ACP) - A combinding PAPR reduction method for DCO-OFDM UOWC
摘要： Optical orthogonal frequency division multiplexing (OFDM) has been adopted in underwater optical wireless communication (UOWC) system, to achieve high data rate and huge bandwidth, as well as to deal with the problem of inter symbol interference. However, it has the problem of high peak-to-average power ratio (PAPR) which will result in serious performance deterioration and increase equipment costs. In this paper, an SLM method is combined with μ-law companding method to reduce the PAPR of UOWC system, which reduce the signal PAPR by 6.8dB and is superior than both the traditional SLM and μ-law companding methods. As for the system bit error rate (BER), the proposed method has better performance than the μ-law companding method. With reasonable tradeoff with the BER, the proposed method has faster convergence than the traditional SLM method.
关键词： peak-to-average ratio,Orthogonal frequency division multiplexing,selective mapping,companding,underwater optical wireless communication
更新于2025-09-19 17:15:36
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High-speed colour-converting photodetector with all-inorganic CsPbBr3 perovskite nanocrystals for ultraviolet light communication
摘要： Optical wireless communication (OWC) using the ultra-broad spectrum of the visible-to-ultraviolet (UV) wavelength region remains a vital field of research for mitigating the saturated bandwidth of radio-frequency (RF) communication. However, the lack of an efficient UV photodetection methodology hinders the development of UV-based communication. The key technological impediment is related to the low UV-photon absorption in existing silicon photodetectors, which offer low-cost and mature platforms. To address this technology gap, we report a hybrid Si-based photodetection scheme by incorporating CsPbBr3 perovskite nanocrystals (NCs) with a high photoluminescence quantum yield (PLQY) and a fast photoluminescence (PL) decay time as a UV-to-visible colour-converting layer for high-speed solar-blind UV communication. The facile formation of drop-cast CsPbBr3 perovskite NCs leads to a high PLQY of up to ~73% and strong absorption in the UV region. With the addition of the NC layer, a nearly threefold improvement in the responsivity and an increase of ~25% in the external quantum efficiency (EQE) of the solar-blind region compared to a commercial silicon-based photodetector were observed. Moreover, time-resolved photoluminescence measurements demonstrated a decay time of 4.5 ns under a 372-nm UV excitation source, thus elucidating the potential of this layer as a fast colour-converting layer. A high data rate of up to 34 Mbps in solar-blind communication was achieved using the hybrid CsPbBr3–silicon photodetection scheme in conjunction with a 278-nm UVC light-emitting diode (LED). These findings demonstrate the feasibility of an integrated high-speed photoreceiver design of a composition-tuneable perovskite-based phosphor and a low-cost silicon-based photodetector for UV communication.
关键词： CsPbBr3 perovskite nanocrystals,Silicon-based photodetector,UV photodetection,Solar-blind UV communication,Optical wireless communication
更新于2025-09-19 17:13:59