【作者】 叶枫；

【导师】 郝莉；

【作者基本信息】 西南交通大学 ， 通信与信息系统， 2008， 硕士

【摘要】 在众多通信技术中,电力线通信受到越来越广泛的关注。电力线通信采用已有的电力线做为媒介进行通信,充分利用了已有的线路设备和网络,具有重复建设少,设备简单,见效快,不易被破坏等诸多优点。但电力线作为传输介质,具有负载多,噪声干扰多,信道衰落和多径延迟严重等等不利因素。本论文首先在MATLAB平台上对电力线的阻抗特性、噪声环境、信道衰落等进行了具体的分析与仿真,得出了包含背景噪声和脉冲噪声的电力线噪声环境特征以及信号衰减及多径引起的电力线信道衰落特征,在此基础上,针对高速电力线宽带通信的OFDM调制解调系统进行了误码率性能仿真。为了改善多径衰落信道条件下的系统性能,本论文在电力线通信系统中引入了无线通信通常使用的信道估计、频域均衡以及频率分集技术,结果表明这些策略一定程度上克服了电力线上的多径衰落,降低了误码率,获得了更好的系统性能。其次,本论文将手写输入应用与电力线通信结合,实现了一个完整的基于电力线通信的手写输入系统。通过电力线进行手写输入信息的传输,能满足使用者在特殊工作环境下,远距离输入的特殊要求,充分利用了电力线通信技术的优势。在硬件平台和软件程序的配合下,系统完成了手写输入信息的采集和编码,载波调制解调,接口转换,系统控制以及终端显示等各项功能。最后的实验测试结果表明该系统方案能可靠地进行信息的手写输入和电力线传输,设计所要求的功能基本实现。最后,本论文针对宽带高速电力线通信,基于INT5200电力线通信芯片,对高速的电力线调制解调器进行了设计。该调制解调器的设计包含了以太网物理层接口,INT5200模块,瞬时保护电路,电源模块,逻辑复位模块等等,适用于利用电力线进行局域网的构建和Internet宽带接入。论文对电路板进行了设计。更多还原

【Abstract】 Among various communication technologies employed nowadays, power line communications (PLC) gains more and more attention. Employing the power line as the communication media, PLC can take full advantage of the existing equipments and networks and possesses the advantages of repeated construction avoidance, the equipment simplicity, the prompt effect as well as the robustness to destroy. On the other hand, as the transmission media, power line exhibits unfavorable properties such as heavy load, severe noise and interference, serious channel fading and multipath delay and so on.First of all, the thesis analyzes and simulates the impedance, noise and signal attenuation characteristics of power line through MATLAB in detail, based on which, the noisy environment characteristics including the background and impulse noise, as well as the channel fading characteristics caused by signal attenuation and multipath propagation, are obtained. Further, the error rate performance of high data rate wideband PLC system using orthogonal frequency division multiplexing (OFDM) technique is simulated. In order to improve the system performance in the multipath fading channel, schemes involving channel estimation, frequency domain equalization and frequency diversity are introduced. Simulation results presented show that the multipath fading effects on PLC system are mitigated to some extent, which brings better error performance.Secondly, in the thesis, hand-writing input application and PLC technique are combined to implement a complete PLC-based hand-writing system. Transmitting hand-writing information through power line, the system can take full advantage of PLC technique to meet the specific needs of different users, including special environment, long distance, multipoint input and so on. Based on the integration of hardware platform and software program, the system can implement functions including hand-writing input information collection, encoding, modulation, demodulation, interface conversion, system control and so on. The final testing results presented indicate that the system is able to implement reliable hand-writing input and PLC transmission, and the design demand is achieved on the whole.In the end, a high data-rate wideband PLC modem based on INT5200 chip is designed. The modem consisting of Ethernet physical interface, INT5200 module, transient protecting module, power supply module, logic reset module and so on can be used for the construction of local area network (LAN) and the access to Internet. Detailed discussions on the circuit design are provided.更多还原