Research of OFDM System for PLC in UCM Based on Precoder Algorithm

In this paper, the channel of the Underground Coal Mine (UCM) PLCs is analysis, which indicates the UCM PLCs is more complex than home PLCs and this channel can be described with multi-path characteristics and strong noise interference characteristics. In conventional OFDM systems a concatenation of Viterbi and Reed Solomon forward error correction with interleaving is used to improve BER performance. But in this channel there are some spectral nulls which make the receiver can not recover the original signal. Accurate modulation should be adopted. Conventional OFDM and precoder OFDM are compared by focusing on one important aspect: BER performance. It will be shown that, for the case of the UCM power line channel, precoder OFDM offers substantial advantages over conventional OFDM. Precoder OFDM is proposed to use in UCM PLCs.