Advanced coding techniques: Theory and practice

In this paper, we compare performance of three classes of forward error correction schemes for 40 Gb/s optical transmission systems. The first class is based on the concatenation of RS codes and this is employed in state-of-the-art fiber-optics communication systems. The second class of codes is the turbo product codes with BCH component codes. The application of these codes in optical communication systems was extensively studied by Sab et al., and Mizuochi et al., and they are being considered for the next generation of long-haul systems. The third class of codes is the low-density parity-check (LDPC) codes that have gained great significance over the past decade. Structured binary LDPC codes, nonbinary LDPC codes, and generalized LDPC codes are considered in this paper. A sophisticated simulator that models all major transmission impairments is used to assess the performance of the error correction schemes. The simulation results show that LDPC codes outperform significantly two other classes of codes.