电力线直接序列扩频载波通信模块研究与设计

【作者】 周立宏；

【导师】 喻寿益；

【作者基本信息】 中南大学 ， 机械电子工程， 2004， 硕士

【摘要】 以低压配电网电力线作为信号载体实现数据通信是90年代初期兴起的一项前沿技术，由于该技术具有潜在的巨大市场和广阔的应用前景，被国外媒体称为“未被挖掘的金山”。本文针对国内水、电、管道煤气等抄表管理难的问题提出了设计基于低压电力线的载波通信模块的设计目标，此通信模块是基于低压电力线载波通信集中远程抄表系统的关键部分。 本文从低压电力线信道特性方面分析了通信实现的难点。低压电力线上信号衰减严重，噪声干扰大，阻抗特性难以匹配，以及低压电力线上的衰减、噪声和阻抗特性呈时变性，使低压电力线上实现数据通信较为困难，这是通信接口模块设计的难点。本文针对以上难点，在研究国内外相关电力线载波通信技术的基础上采用直接序列扩频技术来克服信号的衰减和抑制噪声，并对扩频信号进行二进制频移键控调制来进一步降低噪声对通信的影响。同时，在硬件电路上采用多次滤波滤除噪声，采用高增益接收解调芯片MC13135对接收信号进行两次混频滤波，提取出微弱有用信号，进一步提高通信模块抗衰减能力。硬件电路与电力线耦合部分采用压敏电阻、滤波电容、耦合变压器等来保护通信模块和滤除冲击性干扰。采用ES16来发送和接收扩频信号，对信号进行软件解调，并对接收信号进行容错和两次校验检错，即按位异或校验和累加和校验检错。远程数据读取实验、有效通信距离实验和抗干扰实验的结果表明该通信模块的设计是成功的和可靠的。最后，本文提出了通信模块的进一步研究内容。更多还原

【Abstract】 Exchanging data through low -voltage powerline is a leading edge technology started in early 1990s . Because of its large latent markets and its wide applications, it is called "the undigged gold mountain". In terms of the difficulties of transcription of consumption of water, power and gas, this paper set up the goal of designing the powline carrier communication interface. This interface is the key part for remote transcription system based on powerline carrier technology.From the aspects of the channel characteristics of low-voltage powline, this paper analyzes the difficulties of communication through powerline . Signal attenuates sharply on powerline, noise is too high , impedence match is hard, and these characteristics are also time- varying, which contribute to the difficulty of powerlie communication and the design of the interface. After studying the powerline carrier technology domestic and overseas, this paper employs DSSS technology to overcome the attenuation and noise. 2FSK is used then to furtherly reduce the influence of noise. At the same time , several filters are adopted in hardware circuits. The reception chip MC13135 with high gain is used to promote the capability of anti-attenuation of the interface . The coupling part between hardware circuits and powerline consists of piezo-resistor,filter capacitances and coupling transformer so as to protect the interface and filt the voltage surge. ES16 is used to receive and send the signal of spread spectrum, and demodulate the received signal with software . Fault tolerant and two methods of falt check are employed here. Three kinds of experiments are done, including remote-data reading, effective distance of communication, and anti-interference as well.The results show that the designation of the communication interface is successful and reliable. At last, its further research is presented.更多还原