【作者】 张胜友；

【导师】 刘晓胜；

【作者基本信息】 哈尔滨工业大学 ， 电力电子与电力传动， 2006， 硕士

【摘要】 利用低压电力线作为载体进行数据传输有着广阔的应用前景和经济价值。针对低压电力线上的强噪声、大衰减等不利于数据安全可靠传输的因素,本文提出将跳频技术与电力线载波通信系统相结合的一种新方法,增强了系统的抗干扰能力。首先,本文介绍了课题的背景和意义,对当前的电力线载波通信和跳频技术的研究现状分别进行了论述,提出了一种基于跳频技术的电力线载波通信方法。其次,在实际测试的基础上,分析了低压电力线信道的信道特性,建立了低压电力线信道模型,并仿真了10kHz~1MHz的低压电力线信道特性。再次,研究了跳频通信系统的工作原理及其关键技术,根据低压电力线信道特性,设计了一个电力线跳频通信系统,并建立了这个系统的仿真模型。利用低压电力线进行跳频通信,需要对传统的跳频技术做相应的改变。本文在系统设计中,一方面,采用直接式相关器解跳,降低了接收端的采样速率,也简化了滤波器设计工作;另一方面,将FSK调制与频率合成器结合在一起,由数据本身直接实现频率调制,大大地简化了系统的软硬件设计。理论分析和仿真试验表明:基于跳频技术的电力线载波通信系统对于电力线上严重的噪声干扰有着良好的躲避能力,系统不会因为某几个频点被干扰而崩溃。文中还指出了进一步提高系统性能的方法。最后,在硬件实现上,本文提出了一种基于DSP和FPGA的系统方案,并进行了功能设计。更多还原

【Abstract】 Using the existing low voltage power line to transmit data has broad application perspective and economic benefits. Point to the heavy noise, strong attenuation, which threat the safety of date transmitting on the low voltage power line, this paper present conjunct the power line communication system with frequency hopping technology, to raise the system’s anti-interface ability.Firstly, the background and purpose of this subject is introduced, and the present state of PLC and FH system is discussed in this paper. A PLC system based on FH technology is presented here.Secondly, on the basis of practicable measurement, low voltage power line channel character is analyzed, power line channel model is established, and the low voltage power line channel character between 10 kHz and 1 MHz is simulated.Thirdly, the principle of FH system and its key technology is studied. According to the character of power line, a PLC-FH system and its model is designed. Frequency hopping communication on the low power line channel need some changes on FH itself. Using direct correlator instead of heterodyne detection, the sample rate is reduced and the filter design is simplify in this paper. Combing the FSK modulation and the frequency synthesizer, letting frequency modulate directly done by the data, the software and hardware designing is simplified.By means of theoretical derivation and simulation, a conclusion is arrived: the PLC-FH system has good anti-interface ability, the system wouldn’t corrupt with some frequency point been polluted.At last, this paper present a system realize solution based on DSP and FPGA, some function is also been designed.更多还原