A study on channel estimation under class A impulsive PLC channel

OFDM (Orthogonal Frequency Division Multiplexing) is the modulation scheme that is widely used in broadband power line communication (PLC). In OFDM transmission, influence of the additive impulsive noise appears on every subcarriers that are the outputs of the DFT in the receiver because of the broad band spectrum of the impulsive noise. As the result, it causes significant degradation of the performance of OFDM transmission. Therefore, an appropriate measure to reduce the influence of impulsive noise is required and many schemes for impulsive noise reduction are proposed. In order to reduce the influence of the impulsive noise effectively from the received signal, precise estimation of transmission channel is necessary. However, the pilot symbols for channel estimation are also affected by impulsive noise and the scheme to estimate transmission channel under impulsive noise channel is required. In this paper, a channel estimation scheme for OFDM transmission under the class A impulsive noise channel using the pilot symbols is proposed. In the proposed scheme, channel estimation and reduction of impulsive noise is iteratively applied in order to increase the precision of channel estimation. As the results of simulation, the precision of channel estimation was improved and the bit error performance almost equivalent to the ideal channel estimation case could be achieved for data symbols.