Coding and diversity schemes for OFDM based narrowband power-line communications

Narrowband communications over power lines has been in use for automatic meter reading (AMR) of electric, gas, and water meters. The major hurdle in the widespread use of this medium is the time varying nature of the channel and impairments such as the presence of colored background noise and large impulse noises in time and frequency domains. In this paper, we model the extremely noisy channel environment and propose a time and frequency domain diversity technique for an OFDM based solution. While COFDM based solutions have been implemented in practice for wireless systems, our work shows that in the presence of impulsive noises and colored background noise, FEC may not be the best solution and it is preferable to use simple redundancy in frequency and time domain to achieve reliable data transmission. The proposed system has very low computational complexity and is specifically designed for AMR application in the CENELEC frequency bands A and B.