Coded Flip-OFDM for Unipolar Communication

摘要

Optical wireless communication is the potential alternative resource for the congested RF wireless spectrum. Multicarrier communication technique Orthogonal Frequency Division Multiplexing (OFDM) is used in optical wireless transmission systems. To guarantee unipolarity of optical wireless transmission, Flip-OFDM is one of the promising unipolar OFDM technique developed. The key constraint in optical medium is the transmitted power due to skin and eye safety issues. Along with power efficient modulation technique like Flip-OFDM, the transmitted optical power can be further reduced by using error control coding. In this paper, Flip-OFDM is combined with forward error correction to provide significant improvement in system performance in terms of reduced error probability. The uncoded and channel coded Flip-OFDM is compared. Coded Flip-OFDM with QAM (quadrature amplitude modulation) offers coding gain of 4.2dB for BER of 10~4.