Research On OFDM And Its Application In Low-voltage Power Line Carrier Communication

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.