Generalized Permutation Coded OFDM-MFSK in Hybrid Powerline and Visible Light Communication

Channel impairments in powerline communication (PLC) and visible light communication (VLC) technologies are one of the causes of performance degradation in hybrid PLC and VLC (HPV) systems. In this study, we focus on one of the inherent noise types in PLC channels; impulse noise (IN), which is characterised by short bursts of rapidly modified amplitudes caused by random switching of electrical devices in a power network. Recently, a permutation coded orthogonal frequency division multiplexing (OFDM) with the $M$ -ary frequency shift keying ( $M$ FSK) scheme, in short, PC OFDM- $M$ FSK, was proposed for IN mitigation in PLC systems. It is conceived that the robustness of this scheme against IN in standalone PLC systems will enhance the error performance of the HPV system. Furthermore, since one of the disadvantages of the PC OFDM- $M$ FSK scheme compared to that using only the classical OFDM scheme, is degraded data rate, we propose a generalised PC OFDM- $M$ FSK scheme to improve the degraded data rate. This study shows that the use of OFDM- $M$ FSK improves the performance of an HPV system compared to that using only the classical OFDM modulation scheme by a signal-to-noise (SNR) ratio gain of 6 dB at a bit error rate (BER) of 10⁻⁴. Furthermore, an SNR gain of approximately 3 dB and reduction in the decoding complexity of the PC OFDM- $M$ FSK HPV system is achieved using a soft-decision Hungarian-Murty (HM) decoder. Moreover, the generalisation of the PC OFDM- $M$ FSK HPV system does not increase the decoding complexity when the SD HM decoder is used.