Noise Mitigation over Powerline Communication Using LDPC-Convolutional Code and Fusion of Mean and Median Filters

摘要

In this paper, we propose a new impulse noise mitigation approach in Orthogonal Frequency Division Multiplexing (OFDM) signals over Powerline communication (PLC) channel. Recently LDPC-Convolutional Code (LDPC-CC) has received much interest as an alternative to LDPC codes for its advantages and low complexity. The proposed approach exploits the redundancy introduced by LDPC-CC and cyclic prefix (CP) added to the OFDM transmitter to recover noisy coefficients. It is based on the fusion of median and mean of their neighboring coefficients using a window and a dynamic threshold calculated on the basis of noise variance and the peak value of the noise in the received signal. Detection of noisy coefficients takes into consideration the neighboring coefficients. The proposed technique presents a good robustness to impulse noise performance without adding a big complexity to the transmission system. Promising results have been achieved by the proposed approach when compared to filtering and coding techniques alone.