Error correction using LDPC code for performance improvement in clipped and biased OFDM with direct detection over optical fiber

Paper presents a performance comparison for DC-biased OFDM and clipped OFDM for unipolar transmission over optical fiber communication systems with forward error check encoder, LDPC (32400, 64800). Asymmetrically clipped OFDM is being studied intensively for possible future technology in a short range optical channel with low power applications as well as adaptive data rate allocation in network because same optimized design parameters can be used for large constellation size (up to QAM-1024). OFDM over optical fiber comes with several challenges like accommodation of existing opto-electric resources for futuristic approach. Inclusion of FEC scheme improves the BER performance, although data array size for transmission and total electrical power has increased. For OFDM without FEC we need laser power 3 dBm for lowest BER in range ($1^{*}10^{-5}$ and $1^{*}10^{-7}$) where as in LDPC coded OFDM lowest BER ($1^{*}10^{-5}$ and $1^{*}10^{-s}$) is observed for biased and clipped OFDM respectively.