On the Mitigation of Impulsive Noise in Power-Line Communications With LT Codes

In this paper, we present a concatenated coding scheme that mitigates the effect of impulsive noise in orthogonal frequency-division multiplexing-based power-line communications (PLC) systems. What we propose is a novel technique that uses Luby transform (LT) codes as the outer scheme along with irregular low-density parity check (LDPC) codes as the inner code applied on the physical layer. The scheme fully exploits the features of LT codes and mitigates the impulsive noise effect even under high impulse level conditions. By introducing a small percentage of additional packets at the LT transmitter, the packets that are mostly affected by impulsive noise on the PLC channel are treated as erasures at the LT decoding procedure, thus resulting in a reduced error rate. In this innovative scheme, the receiver can identify the packets to be marked as erased even without channel state information, just by taking into account the properties of the inner LDPC code. Furthermore, we propose a method according to which the redundancy introduced by LT codes can be kept at low levels.