Cyclostationary noise mitigation in narrowband powerline communications

Future Smart Grid systems will intelligently monitor and control energy flows in order to improve the efficiency and reliability of power delivery. The monitoring and control require low-delay, highly reliable, two-way communications between customers, local utilities and regional utilities. Narrowband powerline communication (NB-PLC) systems operating in the 3-500 kHz band have been standardized to enable these two-way communication links. In NB-PLC systems, additive non-Gaussian noise/interference is primary limitation to the communication performance. From field trials, the dominant source of this non-Gaussian noise/interference is cyclostationary. In this paper, we address the problem of cyclostationary noise mitigation in NB-PLC systems and other orthogonal frequency division multiplexing (OFDM) systems. The contributions of this paper include developing a parametric noise estimation algorithm based on switching linear autoregressive (AR) process, and a simple adaptive noise whitening approach that can be immediately integrated into the conventional OFDM transceiver structure to improve its performance. In our simulations, the proposed noise whitening method achieves up to 3dB SNR gain over conventional OFDM systems at SNRs higher than -3dB.