Comparação das técnicas de modulação multiportadoras aplicadas às comunicações via rede elétrica

Abstract

The use of the low voltage energy grid as high speed communication networks, known as Power Line Communication – PLC, opens up the possibility to establish low cost widespread local area networks services such as internet. In this master thesis dissertation, transmission issues on the power line are investigated and modeling aproaches are investigated. Multi-carrier modulation based on orthogonal transmultiplexer is used, because of its fast algoritms capabilities. Three diferent techniques are compared: Orthogonal Frequency Division Multiplexing, Discrete Wavelet Multitone through Extended Lapped Transform and Wavelet Packet Modulation. The main characteristics of each technique, including their computational cost, are described based on the filter banks theory. The system performance is analysed in terms of the bit-error rate versus signal-tonoise rate in a multipath powerline channel.