基于高效调制的电力线通信系统设计与实现

发布时间：2018-04-30 05:36

本文选题：电力线载波通信 + 高效调制　；参考：《东南大学》2016年硕士论文

【摘要】：电力线载波通信(Power Line Communication, PLC)技术是利用现有的电力线网络进行数据传输的通信技术,具有覆盖范围广、无需重新铺设线路等优势。此外,国家大力建设的智能电网也需要PLC技术来支撑。所以,如何在电力线网络上获得可靠、快速、低成本的通信具有重大的理论和实用价值。目前窄带低压电力线通信中,一般所用调制方式有二进制相移键控(BPSK)、频移键控(FSK)以及正交相移键控(QPSK)等。与这些传统的调制方式相比,高效调制技术拥有更窄的带宽。与此同时,解调器中的冲击滤波器不仅可将相位跳变转化幅度冲击,还具有窄带带通特性,因此基于冲击滤波器的高效调制通信系统具有很强的抗噪声与衰落能力。本文主要研究了如何使用高效调制技术实现电力线载波通信,并且在获得可靠通信的基础上,尽可能地降低整个系统的成本。首先,对电力线信道的衰减和噪声特性进行了分析与建模,为后面的分析与仿真提供基础。其次,介绍了扩展的二元相移键控(EBPSK)调制原理、冲击滤波器以及FPGA开发平台。设计了基于FPGA的EBPSK调制器与解调器的结构,并在FPGA中予以实现。在本系统中,主要设计与实现了串口通信、时钟、调制、位同步及帧同步等模块。然后,对PLC系统中的纠错编码技术进行了讨论,选取了几种在短码长下具有优异性能的信道编码进行仿真对比,并推导了基于冲击滤波器的EBPSK软判决译码中的可靠性度量公式。最后,介绍了多元位置相移键控(MPPSK)及改进的MPPSK调制原理,提出了基于改进的MPPSK调制的寻最大值法解调方案,并仿真证明了此方案下的MPPSK通信系统相对于EBPSK通信系统的优越性。并且在EBPSK接收机的基础上,给出并实现了全数字MPPSK解调器,进一步降低了成本,同时将RS编解码添加到本系统中以获得更好的传输性能。
[Abstract]:Power Line Communication (PLC) technology is a kind of communication technology which uses the existing power line network for data transmission. It has the advantages of wide coverage and no need to lay new lines. In addition, the smart grid that the country builds energetically also needs PLC technology to support. Therefore, how to obtain reliable, fast and low cost communication on power line network has great theoretical and practical value. At present, in narrow band low voltage power line communication, the general modulation methods are binary phase shift keying (BPSK), frequency shift keying (FSKK) and orthogonal phase shift keying (QPSK). Compared with these traditional modulation methods, the efficient modulation technology has narrower bandwidth. At the same time, the impulse filter in the demodulator can not only transform the phase jump into the amplitude shock, but also have the narrowband pass characteristic. Therefore, the high-efficiency modulation communication system based on the impulse filter has strong anti-noise and fading ability. This paper mainly studies how to use efficient modulation technology to realize power line carrier communication and reduce the cost of the whole system as much as possible on the basis of obtaining reliable communication. Firstly, the attenuation and noise characteristics of power line channel are analyzed and modeled, which provides the foundation for the analysis and simulation. Secondly, the extended binary phase shift keying (EBPSK) modulation principle, impulse filter and FPGA development platform are introduced. The structure of EBPSK modulator and demodulator based on FPGA is designed and implemented in FPGA. In this system, serial communication, clock, modulation, bit synchronization and frame synchronization are designed and implemented. Then, the error-correcting coding technology in PLC system is discussed, several channel codes with excellent performance under short code length are selected for simulation and comparison, and the reliability metric formula of EBPSK soft decision decoding based on impulse filter is deduced. Finally, the multivariate position shift keying (MPPSK) and the improved MPPSK modulation principle are introduced, and the demodulation scheme based on the improved MPPSK modulation is proposed. The simulation results show that the MPPSK communication system is superior to the EBPSK communication system. Based on the EBPSK receiver, an all-digital MPPSK demodulator is presented and implemented, which further reduces the cost and adds RS codec to the system to achieve better transmission performance.
【学位授予单位】：东南大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：TN913.6

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