基于TH预编码的单载波4QAM低压电力线通信方式研究-信息与通信工程专业论文.docxVIP

Abstract Low voltage power line communication is a means of communication which uses the low voltage power line as the communication medium to transmit the data. This technology has the characteristics of accessing conveniently, no wiring, constructing speedily and wide distribution compared with other cable communication medium. The application prospect on smart home and broadband access of Internet has been concerned widely, and it is also one of the mostly technology, which can resolve the problem (we call it the last kilometer). However, the low voltage power line channel has the characteristics of stronger time-varying and bigger interference compared with other cable communication medium, so we must choose proper transmission modes which has stronger resistance to interference to transmit data. Now the OFDM scheme has been used in the actual power line modem chip, this technology has the characteristics of high bandwidth efficiency and strong anti-interference ability, but the transmitter and receiver need the transform of IFFT / FFT, so the equipment is relatively complex. The paper proposed a modulation method of single-carrier 4QAM based on TH pre-coding, which adopts the mode of combining TH pre-coding and adaptive equalizer. The signals are pre-equalized by the TH pre-coding filter in the send end in the basis of channel estimation, and the signals are equalized again by the adaptive equalizer in the receiver. So this method can suppress the ISI which is produced by the multi-path effect. It can reach similar performance when the complexity is reduced compared with OFDM technology. The paper firstly introduced the characteristics of channel and noise in the low voltage power line, and shows the simulation of the low voltage power line channel and noise model, and then describes the basic principles, realization, advantages and disadvantages of OFDM technology which is commonly used in the power line communication, two key technologies in the OFDM which