下载文档原格式
可见光通信技术论文可见光通信技术可见光通信系统具有十分广阔的应用前景。
下面是为大家精心推荐的可见光通信技术论文，希望能够对您有所帮助。
室内LED可见光通信技术分析摘要：本文主要分析了LED可见光通信的基本原理及尖键技术，然后就LED可见光通信的未来应用进行展望，以期促进LED可见光通信技术的发展与完善。
矢键词：室内LED；可见光通信；应用展望:TN929 : ALED可见光通信系统具有十分广阔的应用前景。
但当前LED可见光通信技术还不够成熟，距离商用还有一定差距，仍需要我们不断加强研究以进一步优化系统的各项性能。
一、室内LED可见光通信原理简介室内LED可见光通信的基本原理是利用灯光的“明”和“暗”来分别表示数字信号“ 0”和“ 1”，然后将广播、图像、音频、影像等待发射的信息调制后加载到LED灯光上，通过LED灯光的高频闪烁将信号传送出去。
由于LED向应速度极快，不会对人眼造成影响，因此能够在正常照明的同时实现无线通信功能。
在信号接收端一般设置有光电探测元件，可以对接收到的可见光信号进行放大和解调处理，进而将其重新还原成广播、音频、影像等信号。
二、室内LED可见光通信的矢键技术1.光源布局一般情况下，光源布局要考虑两点：一是组成阵列光源的内部LED灯的数量及排列方式；二是整个室内LED光源的分布。
在室内光源设计中，为满足国际照明标准，通常将LED光源设计为白光LED阵列形式，构成各LED 阵列的LED个数由LED间隔大小决定，而间隔大小需要综合考虑中心区域的光强度。
在LED排列问题上，则要充分考虑信号接收面的照度要求与光强分布。
同时在设计LED数量及排列时，还要考虑码间串扰问题。
为提高通信质量，还应结合房间大小及内部设施陈列，尽量使室内同一水平面上的光功率保持一致，防止出现通信死角。
此外，考虑到行人、设施等造成的遮挡，不可避免地会产生一些阴影区，对此可通过增加光源数量来减少阴影效应，但过多的光路径又会引发严重的码间干扰，因此根据室内实际情况科学设计LED阵列光源是提高通信效果的尖键。
可见光通信系统设计与应用研究随着无线通信的发展，人们对于更快速、更安全的数据传输有着日益增长的需求。
在这种需求下，可见光通信系统作为一种新兴的无线通信技术受到了越来越多的关注。
本文将就可见光通信系统的设计与应用进行研究，介绍其基本原理、系统设计要点以及各种应用场景。
可见光通信系统是利用可见光波段进行数据传输的一种技术。
与传统的无线通信技术相比，它具有以下优势：不会受限于频谱资源，免受电磁干扰的影响，具有较高的安全性。
同时，可见光通信系统还可以利用环境光进行通信，减少了对设备的依赖性，具有较低的成本。
在可见光通信系统的设计过程中，主要需要考虑以下几个要点：传输速率、传输距离、功率控制、多用户接入以及抗干扰能力。
传输速率是衡量系统性能的一个重要指标，需要根据实际需求和条件来确定。
传输距离受限于光的传播特性，需要优化调整发送功率以及接收灵敏度来保证通信质量。
功率控制是为了避免光强过大或过小而导致的误码率上升或传输距离不足等问题。
多用户接入是指如何实现多个用户同时进行通信而不相互干扰。
抗干扰能力则是为了保证通信质量在其他电磁波或光源干扰的情况下依然能够正常进行。
可见光通信系统的应用场景广泛，涉及到室内通信、室外通信以及特定场合的通信。
在室内通信方面，可见光通信系统可以作为Wi-Fi信号的补充，避免了频谱资源的竞争，提供了更高速、更安全的数据传输方式。
在室外通信方面，可见光通信系统可以应用于城市中的街道照明灯杆，通过调制控制灯光的亮暗来进行数据传输，实现城市智慧照明。
此外，可见光通信系统还可以在特定场合如地铁站、医院等场所进行应用，以提供更快速、更安全的无线通信服务。
尽管可见光通信系统在各个方面都具有许多优势，但它也存在一些挑战。
首先是可见光通信系统对于视线的要求较高，遮挡和障碍物会影响通信质量；其次是系统设计复杂，需要考虑到光的传播特性、多径效应等因素；此外，可见光通信系统的设备成本还相对较高，需要进一步的研究和开发来改善。
Proceedings of the 29th Annual International Conference of the IEEE EMBSCité International, Lyon, France August 23-26, 2007.Using Zigbee to Integrate Medical Devices Paul Frehill, Desmond Chambers, Cosmin RotariuAbstract—Wirelessly enabling Medical Devices such as Vital Signs Monitors, Ventilators and Infusion Pumps allows central data collection. This paper discusses how data from these types of devices can be integrated into hospital systems using wireless sensor networking technology. By integrating devices you are protecting investment and opening up the possibility of networking with similar devices.In this context we present how Zigbee meets our requirements for bandwidth, power, security and mobility. We have examined the data throughputs for various medical devices, the requirement of data frequency, security of patient data and the logistics of moving patients while connected to devices.The paper describes a new tested architecture that allows this data to be seamlessly integrated into a User Interface or Healthcare Information System (HIS). The design supports the dynamic addition of new medical devices to the system that were previously unsupported by the system. To achieve this, the hardware design is kept generic and the software interface for different types of medical devices is well defined. These devices can also share the wireless resources with other types of sensors being developed in conjunction on this project such as wireless ECG (Electrocardiogram) and Pulse-Oximetry sensors.MANY devices that exist today by the bedside in the hospital ward, intensive care unit or other clinical setting have data output features over serial ports and other types of interfaces such as USB. These devices are usually considered a significant investment and are usually purchased in an ad hoc fashion as required when finance becomes available. The consequence of this is that devices are often from different manufacturers that don’t support any standard protocol. This can make integrating these devices into a single network difficult.In the hospital ward Vital Signs monitors, Ventilators and Infusion Pumps of many different brands are usually portable and wheeled from patient to patient as required. By networking these devices the hospital gains all the advantages associated with storing patient data centrally in electronic records. By making the device part of a wireless sensor network such as a Zigbee [1] network there are several more advantages including, cable replacement,mobility and location management. Once these devices are networked they can also use the infrastructure of other deployments of similar wireless sensor networks in the surrounding environment.To achieve this type of solution each device must be fitted with a piece of hardware that will act as a serial to wireless bridge, a Medical Device Interface (MDI). This MDI will allow the device to receive and transmit data within the wireless sensor network. This inexpensive hardware will be generic to fit a wide range of medical devices. Similarly the firmware can be kept generic and any specific device communication protocols can be implemented on a server on the network backend.The work described in this paper is part of a larger project, the goal of which is to provide a complete patient monitoring system. Other features of the overall system will be to provide ECG (Electrocardiogram) and Pulse-Oximetry data in a novel way over a wireless sensor network using expertise gained on prior projects [2].RELATED WORKThe concept of using wireless sensor networks for Medical Care and wireless patient monitoring has been explored by others but integrating data from other devices is generally not discussed. There is ongoing related work in patient monitoring u sing wireless sensors such as the “CodeBlue” project at Harvard [3]. Others have also proven successful with wireless sensor networks designs for medical sensors [4] and in the management of sensor data [5]. It has been identified that it is desirable to wirelessly enable existing medical devices that provide vital signs data using technologies such as Zigbee [6], [7]. The research described in this paper aspires to meet these requirements. The use of wireless sensor networks within the hospital has been extensively examined. Moreover, other wireless technologies within the same frequency band, such as IEEE 802.11 [8], have existed within the hospital for some time [9].III. REQUIREMENTS ANALYSISWireless TechnologiesEstablished standards for wireless applications, such as Bluetooth [10] and IEEE 802.11, allow high transmission rates, but at the expense of power consumption, application complexity, and cost. Zigbee offers low cost, low power devices that can communicate with each other and the outside world. ZigBee's self-forming and self-healing mesh-network architecture lets data and control messages pass from one node to another by multiple paths. This is particularly useful in a hospital environment where interference from walls,people and general obstacles is a major issue. Zigbee is based upon the IEEE standard 802.15.4 [11] for radio hardware and software specification.MobilityZigbee enabled devices support a sleep mode. An off-line node can connect to a network in about 30 ms .Waking up a sleeping node takes about 15 ms, as does accessing a channel andtransmitting data. If the requirement is to collect data once a minute the device can be placed in a power saving mode saving significant amounts of energy and increasing the battery life. In sleep mode a Zigbee chip can assume as little as 1.0uA [12]. This is particularly important in a medical setting where patients are often on the move while still attached to medical devices.Co-existenceBoth Zigbee and IEEE802.11 operate in the license-free industrial scientific medical (ISM)2.4GHz frequency band.IEEE802.11 is already in widespread use within hospitals which would encourage the adoption of Zigbee solutions in the same environment. However care has to be taken to avoid interference between these 2 neighbouring technologies as described in the paper entitled “Coexistance of IEEE802.15.4 with other systems in the 2.4GHz-ISM-band”[13]. By selecting an appropriate channel, after performing a simple site survey, these problems can be easily avoided.Device ParametersTypical readings available on a ventilator are Inspiratory Tidal Volume, Expiratory Tidal Volume, O2 concentration, Respiratory Rate, Peak Pressure, Expired Minute Volume and Mean Airway Pressure. The settings on the ventilator are also of interest to medical staff. The most typical settings we’ve chosen are Inspiratory Tidal Volume, Minute Volume, O2 Concentration, I:E Ratio, Breath Duration and Inspiratory Flow.Similarly we have chosen some common parameters for Vital Signs Monitors. These are Respiratory Rate, Non Invasive Blood Pressure, SPO2 and Temperature. The third device we selected parameters for is the Unfusion Pump. The common parameters we are most interested in here are Volume, Time, Ramp and Occlusion Pressure. Further parameters can be easily added to the system in the future.BandwidthFor development purposes we analysis a Maquet Servo-I [14] which supports all the ventilator parameters described above. This ventilator works in a command response manner. When initial configuration has taken place 2commands which are 7 bytes long each will produce 2 responses of 67 bytes each. Therefore even in a multi hop mesh network it is anticipated we would be able to support several of these devices plus other types of devices on the same 802.15.4 channel.ScalabilityThe ventilator, having the most parameters of the devices studied, requires the most bandwidth. Experiments carried out on a CSI Vital Signs Monitor [15] show that 44 bytes of data will produce all the information we are interested in. A Braun Infusion Pump [16] exports 24 bytes of data to produce the 4 parameters we need. For any of the medical devices we are concerned with, the readings are typically only required once a minute in a hospital environment. All these devices have their own alarm mechanisms built in; we are purely providing a means of exporting the data automatically. Theoretically a single Zigbee network could have above and beyond 600 Ventilators as each device only requires less than 1KB of bandwidth per minute. The frequency at which we capture the data is decided upon by the clinical staff themselves. A 1 minute interval is a typical value, however even if they were to require the data every few seconds it is clear the network could still support a large number of devices.IV. SYSTEM ARCHITECTUREA. High-Level ArchitectureThe overall System Architecture consists of a Wireless Personal Area Network (WPAN) and a Local Area Network. The WPAN implemented as a Zigbee network communicates with the LAN via a gateway. This gateway also serves as the WPAN coordinator which is responsible for forming the network. Each medical device has a Zigbee node attached(MDI) which enables data to be transmitted wirelessly to the Gateway and then onto a Server existing on the LAN. See Fig. 1 below for a graphical representation of this. When an MDI is powered on it automatically joins the network and makes itself known to the Server. A user can then associate this device with a patient using a GUI client. Once an association has been completed the MDI will be notified to begin transmitting data. Data received by the server will be stored in the Electronic Health Record (EHR) for that patient and displayed on any GUI Client that is subscribed.Figure 1. High-Level ArchitectureB. Medical Device InterfaceThe diagram in Fig. 2 below shows the key components of the MDI. The hardware comprises of a Zigbee module, a microcontroller and an RS 232 Interface. The microcontroller is responsible for interfacing with both the RS232 Interface and the Zigbee module.Fi gure 2. MDI Block DiagramWhen the MDI is powered on, the Zigbee stack will automatically join a Zigbee network within range. Next the MDI will announce an ID which is also visible on the external surface of the device. This is done using a protocol we designed for this project. The protocol supports these types of status messages in addition to supporting the actual real data we are interested in. At this point it is possible to make an association with the MDI. To achieve this, the administrator selects the ID from an automatically generated list on screen, a patient demographic and a type of medical device which is supported in the system. This process results in the server sending the correct RS232 settings to the MDI for the medical device that it is connected to. Now that the system can communicate directly with the medical device the server will send any necessary commands to initiate a data stream from the device.C. Server FunctionalityThe server is responsible for decoding specific medical device data. This functionality is implemented in a DLL (Dynamic Link Library) that is run on the server. There is one DLL for each type of medical device the system supports which allows for future medical devices to be supported without upgrading the server software. Any future device can easily be supported within the DLL framework by simply inheriting from the appropriate class for that particular type of device. These DLLs are loaded at run-time and have a standard interface that each designer must adhere to in order to interoperate with the system. A designer must also complete an XML file from a template to indicate which features the new medical device supports. The DLL onlyhandles device specific information; the main server application decodes this information from our project protocol.Figure 3. New Data RequestWhen the DLL is loaded by the server application it will receive a value to represent how frequently the server wants GUI data. This value is used to create the interval timer represented in the above UML diagram. When this timer expires the DLL will check the current state it has for the ventilator. Fig.3 above shows an activity diagram representing a sequence of events surrounding this timer expiration in a DLL for a ventilator. When the timer expires the DLL retrieves the command in the form of a byte array of ASCII characters. Next the DLL raises an event containing the byte array. The server application accepts this event through its event handler,encodes it in our protocol and sends it to the medical device.Figure 4. Handling New DataWhen the medical device returns a response to the server application this data is passed to the DLL as shown in Fig. 4 above. If the DLL does not receive any data within a specified timeout period the DLL will re-initiate communication with the medical device. Data that is received by the DLL is checked to see if it is consistent with the format expected and that the checksum is valid if applicable. Once the data is proven to be valid, a generic data structure that is shared between the server application and clients is populated. Finally the DLL will raise another event, this time to indicate that GUI data is available. The server then multicasts the new data to anyclient that is subscribed to that address. The Server could be extended to integrate with existing hospital systems using HL7 [17] or another uniform interface that is designed specifically for wireless sensor networks could be used such as that developed by DERI [18].V. LABORATORY RESULTSThe architecture described here has been implemented and tested successfully in a laboratory environment. For this purpose we connected the MDI to a PC simulator designed to act as a Maquet Servo-i ventilator. The Maquet ventilator can return breath readings and settings. To capture these, the SDADB and SDADS Maquet commands are sent to specify which breath readings and settings we wish to retrieve. Then by sending the RADAB and RADAS commands periodically we can capture up to date information from the ventilator.Fig. 6 shows the simulator handling these commands at runtime.Figure 6. Ventilator SimulatorAs described in the Architecture the Server DLL maintains a state for each end device so it knows what information to expect in return. In our experiments we successfully retrieved ventilator data at 5 second intervals. We have designed a GUI client which we successfully subscribed to receive this ventilator data. We are collaborating with a local hospital that use the Maquet ventilator and their requirement is data collection at 1 minute intervals. These results are very positive prior to usability tests in the hospital with the actual ventilator. We also performed a limited amount of range testing in the laboratory. We achieved a range of 20m within the confines of the laboratory which would equate to the maximum distance between an end device and a router in the hospital. In addition we carried out some mobility testing by moving the MDI during operation which did not result in any packet loss. Initial results are positive but further extensive testing is needed which will be performed in the hospital environment.VI. CONCLUSIONIn this paper we have shown that a Wireless Sensor Network is a suitable means for capturing data from a medical device. We have discussed how Zigbee meets our requirements in terms of data throughput, power and mobility. Moreover, using this technology we can develop a low cost, scalable solution for a wide range of medical devices. In addition we have an infrastructure that allows us to easily support new devices within the system as needed. This architecture facilitates moving the device data to third party systems and to our own User Interface. We hope that our field trials will result in positive feedback from the clinical staff.第29届IEEE EMIEE国际程序会议城市法国里昂2007年8月23日至27日应用紫蜂技术将医疗器械一体化摘要：无线电技术能够使医疗设备，例如生命体征监视器，呼吸设备以及输液泵做到重要数据的收集。
光纤通信中可见光通信的设计与性能分析近年来，可见光通信作为一项创新性的通信技术，引起了广泛关注。
与传统的无线通信相比，可见光通信利用可见光波段进行数据传输，具有更高的数据传输速率、更低的干扰以及更广泛的应用前景。
在光纤通信中，可见光通信的设计与性能分析成为了一个重要的研究方向。
首先，可见光通信的设计需要考虑光源的选择与调制方法。
光源的选择是设计中的关键一步，常用的光源有白色发光二极管（LED）和激光二极管（LD）。
LED具有低成本、稳定性好、寿命长等优点，但由于其发光效率较低，需要进行高效的调制方式。
而LD具有较高的功率和较窄的光束，但成本相对较高。
根据实际需求和预算，选择适当的光源非常重要。
其次，可见光通信的设计还需要考虑信道传输特性。
由于可见光通信受环境干扰比较大，如光照、障碍物等，设计中必须充分考虑这些因素。
在信道传输特性的研究中，建立合适的数学模型用于预测和优化传输性能是必不可少的。
此外，对于不同的应用场景，还可以采用光学镜面反射技术以提高传输效果。
光接收器是可见光通信设计中的另一个重要部分。
光接收器的设计与性能对可见光通信的传输质量起着至关重要的作用。
常见的接收器有光电二极管（PD）和光电转换器（PDT）。
PD具有快速响应速度、较高的响应度和较大的动态范围，但灵敏度较低。
PDT通过延长光子的旅程，改善了光接收效果，但响应速度相对较慢。
根据实际需求和性能要求，选择适合的接收器可以提高系统性能。
此外，可见光通信的性能分析也是设计中的重要一环。
性能分析可以从多个角度评估通信系统的性能，如传输速率、误码率和系统容量等。
传输速率是衡量通信系统的重要指标之一，与调制方式、信噪比以及信道带宽等相关。
误码率是衡量通信系统错误码字数与传输码字数比例的指标，对于保证信息传输的可靠性十分重要。
系统容量则是指在给定条件下，通信系统所能实现的最大数据传输量。
通过定量的性能分析，可以评估系统的可实现性和稳定性，进行优化设计。
基于白光led的可见光通信系统的设计与实现白光LED可见光通信系统是一种利用白光LED作为发射器和接收器，通过光信号传输数据的新型通信系统。
它的研究和应用在能源资源紧缺和无线电频谱资源饱和的现今社会具有重要意义。
本文将详细介绍白光LED可见光通信系统的设计与实现，以及其在实际应用中的指导意义。
首先，白光LED可见光通信系统的设计要考虑光源的选择和调制方式。
白光LED具有高亮度、低功耗等优势，是一种理想的光源选择。
在调制方式上，可以使用脉冲振荡调制（Pulse Amplitude Modulation，PAM）或正弦调制（Amplitude-Shift Keying，ASK）来传输数字数据，或者使用频分多址（Frequency Division Multiple Access，FDMA）或时分多址（Time Division Multiple Access，TDMA）来传输多用户数据。
其次，在接收端的设计中，需要考虑接收器的灵敏度和信号处理算法。
灵敏度决定了接收器对发送端光信号的接收能力，而信号处理算法则决定了数据的解调和恢复。
为了提高接收器的灵敏度，可以采用高性能的光电检测器，并使用前向误差纠正（Forward Error Correction，FEC）等技术来降低误码率。
在信号处理算法方面，可以使用时域均衡（Time Domain Equalization，TDE）和自适应调制（Adaptive Modulation，AM）等算法来提高系统的容错性和传输速率。
此外，白光LED可见光通信系统还需要考虑光线传输的可靠性和安全性。
光线传输容易受到障碍物的干扰，所以需要设计合理的光线传输路径和布局，避免造成信号衰减和传输中断。
同时，为了保证通信的安全性，可以采用加密技术和认证机制来防止信息泄露和非法接入。
在实际应用中，白光LED可见光通信系统具有广阔的前景和指导意义。
首先，它可以在各种室内环境中实现高速、高容量的无线通信，为人们提供更加便捷和快速的信息传输方式。
可见光通信技术及其应用随着科技的不断发展和智能化应用的推进，人们对于更高速、更安全的通信技术需求也越来越迫切。
在这个背景下，可见光通信技术应运而生。
可见光通信是一种利用可见光波段进行数据传输的技术，其原理基于LED灯或激光器产生的可见光信号进行通信，具有广阔的应用前景。
本文将从可见光通信技术的原理、特点及其应用等方面进行阐述。
首先，可见光通信技术的原理是利用可见光波段的光信号进行数据传输。
它采用的是无线通信方式，但是信号不是通过无线电波进行传输，而是利用可见光作为通信介质。
可见光通信技术通常使用LED灯作为光源，通过调制和解调技术将数据转换为光信号，然后利用光接收器接收并解码光信号，最终实现信息传输。
其次，可见光通信技术具有一些独特的特点。
首先，它可以实现高速通信。
与传统的无线通信技术相比，可见光通信技术的频率较高，使得它的数据传输速率更快，可以满足人们对于高速通信的需求。
其次，可见光通信技术具有较强的安全性。
由于可见光信号不能穿透墙壁，使得这种通信方式在保护数据的安全性方面具有优势，可以有效防止信息泄露。
最后，可见光通信技术无需额外电磁波频带资源，减少了对无线电频谱的需求，有利于减少频带资源的压力。
接下来，我们来探讨可见光通信技术的应用领域。
首先，它可以应用于室内定位和导航。
由于可见光信号无法穿透墙壁，可以利用这一特点对室内的位置进行准确定位，从而实现室内导航和定位服务。
其次，可见光通信技术可以应用于车联网领域。
传统的车载通信系统采用无线电波进行通信，但受限于无线电频谱资源，存在通信干扰问题。
而可见光通信技术则可以利用车内的灯光进行通信，解决了频谱资源的竞争问题，有助于提升车联网通信的安全性和可靠性。
此外，可见光通信技术还可以应用于室内无线网络。
传统的无线网络基于无线电波进行数据传输，但在密集的室内环境中，频谱资源的竞争导致网络速度下降。
而采用可见光通信技术构建室内无线网络可以利用光波的高频率特点，提高网络的传输速率和容量。
可见光通信电路设计作者：胡玉叶范栋梁来源：《报刊荟萃（下）》2017年第11期摘要：实现了利用LED发光装置和光敏器件传输音频信号和模拟波形信号的功能，输入信号通过LM1875芯片进行功率放大后，再利用555组成的多谐振荡器进行信号的调制，调制后的信号驱动LED达到信号传输的目的，接收部分采用光敏电阻接收LED发送的信号，接收后的信号经过滤波处理和功率放大后送8欧喇叭输出，音频信号没有明显失真。
关键词：LM1875；555；LM2576-ADJ1总体设计1.1总体系统构成基于大功率白光LED的可见光通信装置分为：发送端和接收端两大模块，其中又包括电源模块、音频放大模块、调制模块、LED控制输出模块、可见光接收模块、功放模块、数据采集显示模块等7个子模块组成1.2总体系统设计思路发送端和接收端均采用24V单电源供电，电源模块使用LM2576-ADJ芯片组成电压可调电路，首先输入220V交流电源经过变压器变压后输入到LM2576进行稳压处理后作为稳压电源使用；音频放大模块采用采用LM1875作为功放模块，保证输出信号的功率和避免失真；调制模块利用555组成多谐振荡器，将放大后的音频信号和模拟信号调制成方波信号，从而驱动LED进行信号的发送。
发送端的音频信号来源于MP3或者是麦克风，模拟信号来源于信号发生器。
接收端的光敏器件选用光敏电阻，进行信号的接收，接收到发送端发出的信号后首先进行滤波处理后再进行功率放大，接收端的功放模块采用 LM1875作为功放模块，在安装功放模块时也要加装散热片，功率放大后就可以直接输出到8Ω的喇叭上。
数据采集显示模块主要是完成电压、电流信号的采样、处理、显示功能，显示采用了具有中文字库的LCD12864来显示。
调制模块：产品根据设计要求设置了音频调制电路，该电路可将输入的音频信号或单音信号进行调制后控制LED，尽量保证在传输信号过程中保证LED亮度不受输入信号的影响。
2硬件系统设计2.1电源电路设计图此电路将220V交流电经24V变压器经过整流滤波后输出电压为24v*1.414=33.9v经LM2576-ADJ芯片调压后生成24V直流电压。
可见光通信的电路设计陈家栋（桂林电子科技大学海洋信息工程学院广西·北海536000)摘要鉴于新型的无线通信技术可见光通信（Visible Light Communication,VLC ）的发展，本文针对可见光数字通信系统，分析可见光数字信号传输的原理，设计信号传输与处理过程中相关的具体电路，主要包括白光LED 驱动电路、光电检测电路、微弱信号放大电路以及滤波整形电路。
实践结果表明，所设计的可见光通信电路切实可行。
关键词可见光通信光电检测微弱信号中图分类号：TN929.1文献标识码：A 0引言过去几十年里，高速发展的传统无线通信由于频道等因素的限制已经趋向饱和。
可见光通信作为新型的无线通信技术，不占用无线电的频谱资源、超高速的传输特性、易于实现安全传输、尺寸小、节能环保、无电磁干扰，另外VLCS 的通信速率非常高，人眼无法察觉，还能起到通信照明的作用。
基于这些优点，可见光通信备受人们关注。
1可见光通信的原理框图对于不同信号，其传输方式不一样。
本文以数字信号通信为例，并假设其调制方式为2FSK ，设计信号传输及其处理电路。
信号产生、调制以及解调由单片机处理，文中不作分析设计。
可见光数字信号传输的原理框图如图1所示。
图1：可见光数字信号传输的原理框图原理：发射端可利用快速单片机产生数字信号（脉冲序列信号）输入，经功率放大电路放大功率后，驱动LED 灯珠，将电信号转换为光信号。
接收端利用光电二极管将光信号转换成电信号，由于转换出来的电信号比较微弱，故需利用微弱信号放大器将信号进行放大。
经过滤波器滤波和比较器整形后，可输出与发射端信号频率相同的数字信号（脉冲序列信号），输出信号可通过单片机测出频率，以确定其代表的二进制数值（0或1）。
当然这种解调方式成功的前提是发射端发射0或1信号之间的时间间隔要足够长，确保单片机准确测出频率。
2可见光通信的电路设计2.1白光LED 灯珠及功率放大器可采用Risym 公司制作的大功率LED 灯珠，其规格为：白色3W ，色温6500K （±5%），亮度140-165LM ，工作电压3.35-3.6V ，参考电流750mA 。
可见光通信的电路设计作者：陈家栋来源：《科教导刊·电子版》2018年第20期摘要鉴于新型的无线通信技术可见光通信（Visible Light Communication， VLC）的发展，本文针对可见光数字通信系统，分析可见光数字信号传输的原理，设计信号传输与处理过程中相关的具体电路，主要包括白光LED驱动电路、光电检测电路、微弱信号放大电路以及滤波整形电路。
实践结果表明，所设计的可见光通信电路切实可行。
关键词可见光通信光电检测微弱信号中图分类号：TN929.1 文献标识码：A0引言过去几十年里，高速发展的传统无线通信由于频道等因素的限制已经趋向饱和。
可见光通信作为新型的无线通信技术，不占用无线电的频谱资源、超高速的传输特性、易于实现安全传输、尺寸小、节能环保、无电磁干扰，另外VLCS的通信速率非常高，人眼无法察觉，还能起到通信照明的作用。
基于这些优点，可见光通信备受人们关注。
1可见光通信的原理框图对于不同信号，其传输方式不一样。
本文以数字信号通信为例，并假设其调制方式为2FSK，设计信号传输及其处理电路。
信号产生、调制以及解调由单片机处理，文中不作分析设计。
可见光数字信号传输的原理框图如图1所示。
原理：发射端可利用快速单片机产生数字信号（脉冲序列信号）输入，经功率放大电路放大功率后，驱动LED灯珠，将电信号转换为光信号。
接收端利用光电二极管将光信号转换成电信号，由于转换出来的电信号比较微弱，故需利用微弱信号放大器将信号进行放大。
经过滤波器滤波和比较器整形后，可输出与发射端信号频率相同的数字信号（脉冲序列信号），输出信号可通过单片机测出频率，以确定其代表的二进制数值（0或1）。
当然这种解调方式成功的前提是发射端发射0或1信号之间的时间间隔要足够长，确保单片机准确测出频率。
2可见光通信的电路设计2.1白光LED灯珠及功率放大器可采用Risym公司制作的大功率LED灯珠，其规格为：白色3W，色温6500K （€？%），亮度140-165LM，工作电压3.35-3.6V，参考电流750mA。
可见光通信系统驱动电路设计尚建荣【摘要】针对目前可见光通信存在的光源调制频率低、功耗大和传输距离短等问题,研究了模拟和数字调制驱动电路,提出了一款基于DD311的驱动电路.采用频率为200kHz的方波信号作为输入信号,将调制信息加载到白光LED上形成调制光并发射,在接收端通过示波器观测到输出信号与发射信号频率一致.【期刊名称】《光通信技术》【年(卷),期】2015(039)007【总页数】2页(P24-25)【关键词】可见光通信;调制;驱动电路【作者】尚建荣【作者单位】西安邮电大学电子工程学院,西安710121【正文语种】中文【中图分类】TN929.10 引言LED照明可见光通信具有无电磁干扰、保密性好、绿色环保和节约能源等优点，受到国内外众多学者的关注[1，2]。
2014年，法国Oledcomm公司采用基于可见光通信技术的光线传感器完成了智能手机的前置摄像头[3]，通信速率为10Mb/s。
而国内在LED照明可见光通信方面的研究都是基于小功率的，许多关键技术还不成熟[4]。
LED的可见光通信通常采用直接调制方式，根据调制方式，驱动电路选择电流源驱动[5]。
合理的驱动电路设计可以尽量提高输出光功率和传输距离，从而提高系统性能[6～8]。
因此，本文对模拟和数字电路信号的驱动电路原理进行研究，设计基于LED驱动芯片DD311的驱动电路。
1 模拟调制驱动电路模拟调制电路是通过模拟信号控制LED光源的电流大小，从而实现对输出光功率的调制，其原理图如图1所示。
光功率是随着信号变化而变化的，电流的调制度和静态工作点的选择十分关键。
将LED光源的静态工作点设置在P-I特性曲线的中点以防信号失真。
静态工作点选好后应选择尽量大的调制电流，从而提高LED光源的光功率，为光电检测打下良好的基础。
模拟调制驱动电路采用共集电极接法，具体如图2所示。
白光LED串接在三极管T1的集电极上，将基极输入信号的变化转变为集电极的电流变化。
