白光LED室内可见光通信的关键技术

可见光通信是一项新兴基于白光LED的无线光通信技术,具有发射功率高、不占用无线电频谱、无电磁干扰、无电磁辐射和节约能源等优点,能够同时实现照明和通信的双重功能.阐述了可见光通信技术的发展动态,介绍基于白光LED的室内可见光通信系统,并对提高系统整体性能的若干关键技术进行了研究讨论,为白光LED室内可见光通信系统进一步研究提供依据.     

白光LED室内可见光通信的关键技术

可见光通信是一项新兴基于白光LED的无线光通信技术,具有发射功率高、不占用无线电频谱、无电磁干扰、无电磁辐射和节约能源等优点,能够同时实现照明和通信的双重功能。阐述了可见光通信技术的发展动态,介绍基于白光LED的室内可见光通信系统,并对提高系统整体性能的若干关键技术进行了研究讨论,为白光LED室内可见光通信系统进一步研究提供依据。     

基于白光LED的可见光通信技术研究

可见光通信是基于白光LED的新兴无线光通信技术,能够同时实现照明和通信的双重功能,适合在智能家居等领域的应用。本文对基于白光LED的室内可见光通信的研究现状及关键技术、发展趋势进行了研究。     

高速白光LED光通信系统中的码间干扰及其抑制

码间干扰是影响通信系统质量的重要因素,码间干扰的抑制成为改善高速白光LED光通信系统性能的关键.分析了码间干扰的产生机理及其对高速白光LED光通信系统的影响,讨论了传统的抑制码间干扰的方法以及提出分集接收的抑制技术.实验结果表明,分集接收技术能有效抑制码间干扰对高速白光LED光通信系统的影响,系统信噪比平均提高2dB.     

可见光通信中的LED频率特性测试方法研究

针对可见光通信系统中LED的频率特性问题,提出了采用频谱分析仪的测试方案,设计、制作了以PinPD作为光电探测器的LED频率特性测试电路及收发系统。对流明、科瑞、欧司朗、三星等多种商用白光LED以及日本滨松的光通信用红光LED进行了测试,得出了具有较大参考价值的结论。     

用于提升可见光通信调制带宽的微尺寸LED性能研究

基于白光发光二极管(LED)的可见光通信、照明两用系统近年来得到广泛的研究,然而普通LED性能制约了可见光通信调制带宽.为进一步提高LED的调制带宽,可采用微尺寸LED.简要阐述了提高LED调制带宽的方法,综述了近年来在优化可见光通信调制带宽的微尺寸LED性能方面的进展,指出了未来微尺寸LED的研究方向.     

无机钙钛矿白光LED及可见光通信研究进展（特邀）

在现代社会中,白光发光二极管（LED）在照明和显示背板等诸多领域都有着重要的基础性作用。为了获得具有优异性能的白光LED,首先需要获得满足白光LED发光需要的高性能的发光材料。而作为一类新兴的半导体材料,无机钙钛矿（CsPbX₃, X = Cl, Br, I）由于其具有的高发光量子产率、发光波长可调、色纯度高和稳定性好等优点,在发光应用特别是白光LED领域展现出了巨大的潜力。文中将首先分别从光致白光LED和电致白光LED两个方面出发,综述近期在基于无机钙钛矿的白光LED方面所取得的研究进展,随后分别介绍以上两个体系中改性后的无机钙钛矿发光材料与其他发光材料复合形成白光以及无机钙钛矿单组分白光的代表性成果。最后,对钙钛矿白光LED在可见光通信方面所取得的最新进展进行介绍,并且对白光LED以及可见光通信的研究发展趋势与挑战进行了总结和展望。     

基于室内可见光的通信系统性能优化分析

阐述可见光通信特点,基于发光二极管为核心的新型无线光通信技术。探讨影响白光LED传输性能的因素,白光LED传输性能的关键技术,从而提升白光LED传输性能。     

基于可见光通信的信道模型及编码性能分析

目前基于白光LED(发光二极管)的室内可见光通信信道模型的研究主要集中于理论分析,因此信道特性对系统性能的影响还不明确。文章首先分析并优化了室内白光LED通信信道理论模型,并在此基础上研究信道编解码算法,通过Simulink软件搭建信道模型和可见光通信系统来分析信道编码对系统性能的影响,得到了适合可见光通信系统信道特性的信道编码方法。     

基于51单片机的LED可见光通信系统

LED可见光通信是应用前景非常广阔的新兴无线光通信技术.根据可见光通信原理,组建了基于STC89C52RC单片机的LED可见光通信系统,发射板和接收板具有较小体积和较低成本.系统链路采用直射式形式,光强度调制——直接检测技术,通过对白光LED的高速调制,利用串口调试软件验证了PC机间的LED可见光通信.实验结果表明,系统在PC机间能够实现简单的单工数据通信.     

白光LED照明的可见光通信的现状及发展

用室内照明的白光LED光源作为通信基站进行信息无线传输的技术是当前国外光无线通信领域的研究热点之一,是一项有发展前景的新兴技术.文章详细介绍了白光LED照明的室内可见光通信技术在国内外的研究现状,分析了其关键技术,阐述了其发展趋势.     

可见光通信及其关键技术研究

可见光通信系统采用白光发光二极管(LED)作为光源,因而系统具有通信与照明的双重作用,极大地节约了能源.描述了可见光通信的结构与特点,对可见光通信的一些关键技术做了简单的研究,并介绍了可见光通信的发展动态.     

2D Ruddlesden–Popper Perovskite Nanoplate Based Deep‐Blue Light‐Emitting Diodes for Light Communication

Ruddlesden–Popper perovskite, (PEA)₂PbBr₄ (PEA = C₈H₉NH₃), is a steady and inexpensive material with a broad bandgap and a narrow‐band emission. These features make it a potential candidate for deep‐blue light‐emitting diodes (LEDs). However, due to the weak exciton binding energy, LEDs based on the perovskite thin films usually possess a very low external quantum efficiency (EQE) of <0.03%. Here, for the first time, the construction of high‐performance deep‐blue LEDs based on 2D (PEA)₂PbBr₄ nanoplates (NPs) is demonstrated. The as‐fabricated (PEA)₂PbBr₄ NPs film shows a deep‐blue emission at 410 nm with excellent stability under ambient conditions. Impressively, LEDs based on the (PEA)₂PbBr₄ NPs film deliver a bright deep‐blue emission with a maximum luminance of 147.6 cd m^?2 and a high EQE up to 0.31%, which represents the most efficient and brightest perovskite LEDs operating at deep‐blue wavelengths. Furthermore, the LEDs retain over 80% of their efficiencies for over 1350 min under ≈60% relative humidity. The steady and bright deep‐blue LEDs can be used as an excitation light source to realize white light emission, which shows the potential for light communication. The work provides scope for developing perovskite into efficient and deep‐blue LEDs for low‐cost light source and light communication.     

点对点可见光通信系统的光源优化布局研究

点对点可见光通信系统能够支持低能耗、高速率、大容量的数据交互业务。实际应用过程中,光源的选择与布局是关键研究技术之一。为进一步提高系统的通信性能,研究LED构成不同排列方式的阵列光源布局,提出了一种环形-角补偿的阵列光源布局。结果表明,这种光源布局方式能够有效增强接收端的光照度、接收功率及信噪比,并且提升接收端的信号质量,从而有益于点对点高速可见光通信系统的实现与推广。     

Analysis of the effects of LED direction on the performance of visible light communication system

Visible light communication (VLC) is expected to be the next generation of indoor wireless communication. A VLC system uses many LED chips, and its performance is greatly affected by the direction of light-emitting diodes (LEDs). Normally, the LEDs are directed vertically downward to the floor. In this paper, we introduce an LED layout scheme in which the LEDs tilt toward the room corners. The effects of changing LED direction on system performance, including illuminance, received power, and SNR, are analyzed. The analysis is then verified by the simulations.     

Line of sight model for visible light communication using Lambertian radiation pattern of LED

This paper illustrates line of sight model for visible light source and a photodiode in wireless communication. Light‐emitting diodes (LEDs) are predominantly used everywhere like in houses and factories as light source due to development in technology of light sources. Haitz's law predicts an exponential rise in light output and efficiency of LEDs over a period of time. Light‐emitting diodes are having an average life of 50 000 hours with efficiency of 140 lm/W. Light‐emitting diode light sources are used for an eco‐friendly world due to its advantages over conventional wireless communication systems. For communication purpose in the visible light range, the LED and photodiode are used. A visible light communication system with LED as the transmitter and photodiode as the receiver is simulated in MATLAB for line of sight and analyzed using a Lambertian radiation pattern with a different mode number, field of view, and half power angle.     

LED clipping distortion compensation in optical wireless communication via multiple transmit LEDs

A method to reduce signal clipping distortion in indoor optical wireless communication systems based on orthogonal frequency division multiplexing (OFDM) modulation is presented in this paper. Compensating the resulting clipping distortion due to LED operational constrains is achieved through the use of iterative signal clipping (ISC) and multiple light emitting diodes (LED) at the transmitter. ISC technique is based on iterative clipping of the time domain OFDM signal and transmission from a multiple LED transmitter. Transmit LEDs are synchronized, located close to each other, and placed to emit light in the same direction. Hence, the channel path gains from each LED to the receiver photo diode are similar. The received signals from the different LEDs add coherently at the receiver. Reported results demonstrate that the effect of distortion due to clipping is eliminated or significantly reduced based on the considered number of LEDs.     

光纤通信中光源的可靠性

本文详细地讨论了光纤通信的光源——半导体激光器(LD)和发光管(LED)的可靠性;重点论述了长波长光源的可靠性以及筛选方法。     

半导体蓝光

叙述了当前以ＧａＮ为代表的第三代半导体材料的崛起。ＧａＮ因其优良的特性而被用于制造蓝色发光二极管和激光二极管,引起了世界蓝光热。它的研究不仅是高技术的前沿课题,而且是具有巨大市场前景的技术经济竞争领域。蓝色发光二极管和激光器在全色动态显示、固体照明光源、交通信号灯、汽车尾灯、光盘信息贮存以及深海通信等领域都有广阔应用前景。