An enhanced selected mapping technique for joint PAPR reduction and impulsive noise suppression in multi-carrier powerline communications systems
In power line communication (PLC) systems using multi-carrier modulation such as orthogonal frequency division multiplexing (OFDM), reduction of peak-to-average power ratio (PAPR) of OFDM signal and mitigation of the influence of impulsive noise are challenging problems. To deal with these problems in PLC-OFDM systems, this paper proposes an enhanced selected mapping (e-SLM) technique that jointly achieves PAPR reduction on the transmitter side and impulsive noise detection accuracy improvement on the receiver side, where the transmitter selects the best transmit sequence among possible candidates so as to minimize the weighted sum of transmit signal peak power and the estimated receive one, provided that channel state information is available on the transmitter side. On the receiver side, a nonlinear filter is applied to suppress impulsive noise, where the received signal amplitudes exceeding a given threshold are blanked as impulsive noise. Using the proposed e-SLM, peak power of the received signal is reduced below a given threshold level, so that impulsive noise is effectively detected with high accuracy. We evaluate bit error rate (BER) performance of PLC-OFDM systems using the proposed e-SLM method under PLC channel in presence of impulsive noise. Simulation results show the effectiveness of the proposed method in OFDM PLC systems.