A Survey on FEC Codes for 100 G and beyond Optical Networks

Due to the rapid increase in network traffic in the last few years, many telecommunication operators have started transitions to 100-Gb/s optical networks and beyond. However, high-speed optical networks need more efficient forward error correction (FEC) codes to deal with optical impairments, such as uncompensated chromatic dispersion, polarization mode dispersion, and nonlinear effects, and keep the bit error rate (BER) at long distances sufficiently low. To address these issues, new FEC codes, called third-generation codes, have been proposed. A majority of these codes are based on soft-decision decoders and can provide higher coding gain as compared with their predecessors. This paper presents a thorough survey of third-generation FEC codes, suitable for 100 G and beyond optical networks. Furthermore, this paper discusses the main advantages and drawbacks of each scheme and provides a qualitative categorization and comparison of the proposed schemes based on their main features, such as net coding gain and BER. Information about the complexity of each scheme is given as well.