【作者】 孙海翠；

【导师】 张金波；

【作者基本信息】 河海大学 ， 通信与信息系统， 2007， 硕士

【摘要】 本课题为常州通泰仪器仪表厂的委托项目，根据用户的实际设计要求，对正交频分复用(OFDM)技术及其在低压电力载波通信系统中的应用进行了研究。论文首先分析了电力线信道作为通信媒介的特点，建立了实用的信道模型，并对该模型进行仿真。同时研究了可在低压电力线上实现高速数据通信的OFDM技术原理与实现机理，并以所建立的信道模型为基础，建立了与HomePlug 1.0协议相兼容的基于OFDM技术的低压电力线载波通信仿真系统，对系统性能与实现进行了数据仿真与分析，结果表明OFDM技术相对于传统调制技术更适用于低压电力线载波通信。由于同步技术与功率峰均值PAPR是影响OFDM技术得到广泛应用的限制因素，因此，文章针对影响OFDM技术性能的同步技术研究并分析推导了影响OFDM系统性能的三种同步误差，给出了各种误差对实际系统的综合影响水平，针对本文建立的OFDM系统提出了一种改进的基于LM的定时同步算法，计算机仿真结果表明，该算法与传统同步算法相比，提高了同步精度，可进行准确的定时估计和较大范围的频偏估计，计算量小并且冗余度低。同时，文章针对影响OFDM技术性能的降低PAPR技术进行研究，提出了基于帧扩展理论的降低PAPR技术算法，仿真结果表明该算法与传统算法相比在降低系统PAPR能力、增加辅助信息的冗余度以及系统复杂度方面有较大改善。论文最后利用MAXIM公司的集成电力线数字收发器MAX2986完成了电力线调制解调器的设计，为OFDM技术在低压电力线载波通信成功应用奠定了扎实的理论基础。更多还原

【Abstract】 The researches on Low-voltage Power Carrier Communication (PLC) based on orthogonal frequency division multiplexing (OFDM) are presented in this paper. Based on the analysis of characteristics of the practical low-voltage powerline channel, a reliable and applicable channel model is established, which provides a practical and efficient platform for exploring and designing low voltage power network based communication systems.The fundamental theory and realization of OFDM over Low-voltage Power Carrier Communication are concentrated on in the following chapter, and a simulating system complitible with Homeplug 1.0 is proposed. The simulating result and data from the established system shows that the implementation of OFDM on PLC is superior to the conventional modulating methods. Owing to the limiting elements of synchronization and PAPR, The concept of OFDM synchronization is introduced and the effects of synchronization errors on OFDM system performance, including frequency offset, timing offset and sampling frequency offset, are analyzed. An improved synchronizing-timing arithmetic based on LM is put forward, which promotes the precision of timing compared with the conventional methods. Meanwhile, a new arithmetic based on Frame-theroretic approach to reduce PAPR of OFDM is proposed, which promotes the capability of PAR reduction, the required system complexity and transmitting signal redundancy with the exiting methods. The design of PLC Modem with the chipset MAX2986 and MAX2980 of MAXIM Corporation is completed in this thesis.更多还原