Iterative Channel Estimation and Impulsive Noise Mitigation Algorithm for OFDM-Based Receivers with Application to Power-Line Communications

This paper presents a novel iterative receiver used to mitigate the impact of impulsive noise (IN) on orthogonal frequency-division multiplexing (OFDM)-based baseband power-line communications. An adaptive threshold is mathematically derived for the detection of IN under a desired false alarm probability. This detection mechanism is then used to mitigate IN in two stages. Prior to the OFDM demodulation, a pre-IN mitigation block is used to clip the stronger portions of the IN source. This preprocessing significantly reduces the power of the IN spreading into all subcarriers and, thus, facilitates the detection of residual IN in the second stage. After the OFDM demodulation, the proposed receiver iteratively estimates the channel impulse response and reduces IN sources that were not detected by the pre-IN mitigation block. Post-IN mitigation involves the iterative reconstruction of residual IN, which is then subtracted from the received signal. Denoising is also applied to the estimated channel impulse response. Thus, channel estimation and IN mitigation are mutually beneficial. Simulation results confirm that the proposed iterative receiver significantly improves the mean squared error of the channel estimation as well as bit-error rate.