- 标题
- 摘要
- 关键词
- 实验方案
- 产品
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The Optical Barcode Detection and Recognition Method Based on Visible Light Communication Using Machine Learning
摘要： Visible light communication (VLC) has developed rapidly in recent years. VLC has the advantages of high confidentiality, low cost, etc. It could be an effective way to connect online to offline (O2O). In this paper, an RGB-LED-ID detection and recognition method based on VLC using machine learning is proposed. Different from traditional encoding and decoding VLC, we develop a new VLC system with a form of modulation and recognition. We create different features for different LEDs to make it an Optical Barcode (OBC) based on a Complementary Metal-Oxide-Semiconductor (CMOS) senor and a pulse-width modulation (PWM) method. The features are extracted using image processing and then support vector machine (SVM) and artificial neural networks (ANN) are introduced into the scheme, which are employed as a classifier. The experimental results show that the proposed method can provide a huge number of unique LED-IDs with a high LED-ID recognition rate and its performance in dark and distant conditions is significantly better than traditional Quick Response (QR) codes. This is the first time the VLC is used in the field of Internet of Things (IoT) and it is an innovative application of RGB-LED to create features. Furthermore, with the development of camera technology, the number of unique LED-IDs and the maximum identifiable distance would increase. Therefore, this scheme can be used as an effective complement to QR codes in the future.
关键词： CMOS image sensor,machine learning,image processing,RGB-LED,visible light communication (VLC)
更新于2025-09-23 15:22:29
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[IEEE 2020 IEEE Radio and Wireless Symposium (RWS) - San Antonio, TX, USA (2020.1.26-2020.1.29)] 2020 IEEE Radio and Wireless Symposium (RWS) - Optimized LEDs Positions for Channel Analysis Performance of an Intra-Vehicle Visible Light Communication System
摘要： This paper investigates the effect of light emitting diodes (LEDs) positioning and allocation in the channel analysis performance for an indoor intra-vehicle visible light communication (VLC) system. The MATLAB simulation results focus on the received power and the signal to noise ratio (SNR) within a sports utility vehicle. Furthermore, this work aims to validate by investigating two different scenarios, one utilizing two sources of power and the other using three sources of power with various locations, how LED's spatial positioning affects the VLC system and the probability of error. Proving the demand for considering LEDs layout positioning while designing a VLC system.
关键词： SNR,LEDs positioning,Intra-vehicle,Visible light communication (VLC)
更新于2025-09-23 15:21:01
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Quasi blind carrier phase estimation scheme for special-shaped circular (7,1) modulation in high-speed visible light communication
摘要： A novel digital signal processing (DSP) scheme for special-shaped circular (7,1) modulated signals based on quasi blind carrier phase estimation (QBCPE) is proposed. The results show that applying 0.33‰ overhead QBCPE provides similar performance as 3% training sequence data-aided equalization of least mean square (LMS) algorithm.
关键词： Constant Modulus Algorithm (CMA),visible light communication (VLC),least mean square (LMS),circular (7,1) modulation,quasi blind carrier phase estimation (QBCPE)
更新于2025-09-23 15:21:01
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Spatial Carrierless Amplitude and Phase Modulation Technique for Visible Light Communication Systems
摘要： Spatial carrierless amplitude and phase modulation (S-CAP) technique is developed in this paper as a physical layer solution to improve the spectral efficiency of the conventional CAP scheme while preserving its low-complexity transceiver design. The S-CAP technique is proposed and investigated for systems employing the visible light communication technology. An analytical expression for the joint detection of the spatial and signal bits for the user equipment experiencing line-of-sight propagation (LOS) is derived and validated via simulation. The effects of the multipath propagation and user mobility on the bit-error-rate (BER) performance of the proposed S-CAP are also investigated. It is found that the BER performance of the S-CAP in LOS is dictated by the minimum of the channel gains hmin, the signal constellation points, and the channel gain dissimilarity, Δ|h|. The power factor imbalance (PFI) and multiple photodetectors (PDs) are then introduced to improve the performance and mitigate the channel impairments. The use of the PFI and PDs in LOS results in the signal-to-noise gain of 33.5 and 43 dB, respectively. The proposed scheme is thus a novel implementation of the CAP in a multiple-input–multiple-output system and demonstrates its potential as a suitable physical layer solution for the VLC technology.
关键词： multiple-input–multiple-output (MIMO),visible light communication (VLC),Carrierless amplitude and phase modulation (CAP),multipath propagation,spatial modulation (SM)
更新于2025-09-19 17:15:36
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Spectral-Efficient Reconstructed LACO-OFDM Transmission for Dimming Compatible Visible Light Communications
摘要： Dimming control is critical in practical visible light communication (VLC) systems to satisfy illumination demand. Upon exploiting multiple layers of asymmetrically clipped optical orthogonal frequency division multiplexing (ACO-OFDM) signals for simultaneous transmission, layered ACO-OFDM (LACO-OFDM) constitutes a promising spectral-efficient modulation technique for VLC. However, dimming by integrating the industry-preferred pulse width modulation (PWM) to the LACO-OFDM scheme induces severe clipping noise due to the nonlinearity of LEDs. In this paper, we conceive a reconstructed LACO-OFDM (RLACO-OFDM) scheme incorporating the PWM technique for VLC to accommodate the dimming demands for indoor illumination, while maintaining a spectral-efficient communication link. Moreover, superior to its counterparts, the transmitted symbols in the RLACO-OFDM based VLC system can be readily recovered by a standard LACO-OFDM receiver while no additional detection of the PWM signal is required, which reduces the receiver complexity. Numerical results demonstrate that the proposed RLACO-OFDM is capable of realizing high spectral efficiency over a broad dimming range.
关键词： asymmetrically clipped optical orthogonal frequency division multiplexing (ACO-OFDM),layered ACO-OFDM,pulse width modulation (PWM),Visible light communication (VLC),dimming control
更新于2025-09-19 17:15:36
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Energy Efficient Transceiver Design for NOMA VLC Downlinks with Finite-Alphabet Inputs
摘要： Non-orthogonal multiple access (NOMA) is considered as a promising technique in visible light communication (VLC) systems for performance enhancement. In order to improve the system’s energy ef?ciency, we carry out transceiver design for an NOMA VLC system. We develop an optimal power allocation scheme for the system based on ?nite-alphabet inputs, and we propose a joint detection and decoding (JDD) algorithm for signal detection. Comprehensive simulation results demonstrate that our proposed NOMA strategy can achieve signi?cant performance gains over the time division multiple access (TDMA) scheme, and our designed JDD algorithm outperforms the conventional successive interference cancellation (SIC) algorithm for NOMA.
关键词： visible light communication (VLC),?nite-alphabet inputs,joint detection and decoding (JDD),power allocation,non-orthogonal multiple access (NOMA)
更新于2025-09-19 17:15:36
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Red-shift effect in multi-color LEDs based visible light communication
摘要： Visible light communication (VLC) is a short range wireless optical communication system that provides lighting and data transmission, simultaneously. Besides lighting, in order to obtain high data rates, color-shift keying (CSK) which modulates the intensity of light using multi-color light emitting diodes (LEDs) has been introduced in IEEE 802.15.7 VLC standard. In CSK-based VLC (VLC-CSK) systems, some parameters of LEDs such as junction temperature is affected by physical and operation conditions. Junction temperature variations change the power spectral density (PSD) of LEDs, which is known as red-shift effect. In this study, the red-shift effect is examined for the first-time in VLC-CSK systems. The obtained numerical results show that the red-shift effect may dramatically reduce the performance of optical communication system. To eliminate the negative effect of red-shift, an effective solution based on the power normalization is proposed at the receiver side.
关键词： Visible light communication (VLC),red-shift effect,color shift keying (CSK),light-emitting diode (LED)
更新于2025-09-19 17:13:59
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Optical polar based MIMO-OFDM with fully generalised index-spatial LED modulation
摘要： A novel efficient visible light communication (VLC) modulation technique teams as polar fully generalised index-spatial (PFGIS) modulation light emitting diode (LED) for the multi-input multi-output (MIMO) optical polar based OFDM (MIMO-POFDM) system is proposed here. The PFGIS is a spectrally efficient (SE) modulation scheme which introduces an elegant solution to tackle the OFDM signal shaping problem, moreover, the PFGIS improves the optical MIMO-OFDM system SE. In the PFGIS, the Cartesian complex OFDM signal is transformed to polar OFDM (POFDM). Then, the indices of the active LEDs are exploited to convey the POFDM signal components. While, the spatial position of the LEDs are exploited as a spatial modulation (SM). In the SM, the LEDs indices used for data transmission are changed from the case of two LEDs are selected to case where all/multiple LEDs are selected. Subsequently, the proposed system achievable data rate is linearly increased with the LEDs number. The PFGIS gives higher SE even with a lower LEDs number compared with the recently OFDM optical LED index modulation techniques. Simulation results confirm the efficiency of the proposed PFGIS in improving both the achievable data rate and the bit error rate compared with the up-to-date LED index modulation OFDM schemes.
关键词： multi-input multi-output (MIMO),spatial modulation (SM),visible light communication (VLC),polar fully generalised index-spatial (PFGIS) modulation,optical polar based OFDM (MIMO-POFDM),spectral efficiency (SE)
更新于2025-09-19 17:13:59
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[IEEE 2019 IEEE/CIC International Conference on Communications in China (ICCC) - Changchun, China (2019.8.11-2019.8.13)] 2019 IEEE/CIC International Conference on Communications in China (ICCC) - Enhanced Performance of a Phosphorescent White LED CAP 64QAM VLC system utilizing Deep Neural Network (DNN) Post Equalization
摘要： In this paper, a phosphorescent white LED CAP 64QAM VLC system utilizing deep neural network (DNN) and LMS linear equalization (LE) has been experimentally demonstrated. We successfully achieve a data rate of 2.4Gb/s at a 1.1-m indoor free space transmission with the bit error rate (BER) below the 7% forward error correction (FEC) limit of 3.8 (cid:104)(cid:104) 10-3. Compared to the LE and volterra NLE+LE, DNN+LE brings a better performance to mitigate nonlinear distortion. The results show that DNN+LE will be a promising solution for indoor high-speed VLC system
关键词： Deep Neural Network (DNN),Visible Light Communication (VLC),CAP modulation
更新于2025-09-19 17:13:59
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Extended Spatial-Index LED Modulation for Optical MIMO-OFDM Wireless Communication
摘要： An efficient optical modulation technique for multi-input multi-output (MIMO) orthogonal frequency division multiplexing (OFDM) visible light communication system is proposed in this paper. The proposed modulation technique is termed as extended spatial-index light-emitting diode (LED) modulation. In the proposed technique, the indices (the spatial domain) of the LEDs are exploited in a dynamic style to not only get rid of the optical OFDM time-domain (OFDMtd) shaping problem but also to expand the LED indices spatial modulation domain. The indices of the active LEDs in the proposed technique are changed from the two LEDs active situation to the situation where all or several LEDs are active. Moreover, within the selected active LED indices, the power weight distribution and the positions of the OFDM components are varied to expand the resultant spatial domain. Therefore, the proposed technique offers a considerable spectral efficiency improvement over the up-to-date LED index OFDM modulation schemes even with a lower number of LEDs. The key idea of the proposed technique is to maximize the LEDs’ indices spatial position (spatial domain) utilization, where both the power weight allocation and the positions of the complex OFDM time domain components are varying several times over the same active LED indices combination, which improve the optical system spectral efficiency. The simulation results asserted the superiority of the proposed technique, as it improves both the average bit error rate (ABER) and the achievable data rate (R) compared with existing up-to-date OFDM-LED index modulations with even lower computational complexity.
关键词： optical MIMO-OFDM,generalized led index modulation,OFDM-LED index modulation,visible light communication (VLC)
更新于2025-09-19 17:13:59