Noise modeling and OFDM based receiver design in power-line communication

Electromagnetic interference, man-made noise and multi-path effects are the main causes of bit errors in power line communication (PLC). In this paper, frequency domain characteristics of the power-line noise are investigated. The noise amplitude distribution of each individual frequency in the spectrum is analyzed and a suitable noise amplitude distribution model is proposed. A soft-demodulation based receiver for the proposed noise model is derived and its performance is analyzed. In simulations, Zimmermann and Dostert´s wellknown PLC channel model is used. Correctness of the channel simulations is verified by measurements. Orthogonal Frequency Division Multiplexing (OFDM) with convolutional coding and soft-Viterbi decoding is used to evaluate the performance of the receiver under the proposed noise model in terms of the bit-error-rate (BER) for different signal-to-noise ratio values. It is shown that instead of using a Gaussian optimal receiver in an OFDM system for the whole spectrum, utilizing Generalized Gaussian Distribution based receivers with appropriate shape information for each individual subchannel significantly increases BER performance.