A High-Speed Implementation of Open FEC Decoder Based on Optimized Storage Strategy

Following the proposal of 400G fiber-optical communication standard, the next-generation systems with throughput up to 800 Gbps have gained wide interest. This work presents a decoder implementation of the open forward error correction (oFEC) adopted by the Open ROADM standard for high-speed fiber-optical communications. To meet the demand for high speed, a fully pipelined decoding architecture is designed. However, the special coding scheme of oFEC poses great challenges to the memory design, in which potential structural and data hazards can cause pipeline stalls and hence decrease the throughput. In this paper, an optimized storage strategy and several methods are proposed to completely solve those hazards. Equipped with these methods, a hazard-free pipelined decoder for the oFEC is developed and implemented under 28-nm technology. Synthesis results demonstrate that the proposed decoder can achieve a throughput of 902 Gbps, making it suitable for 800G fiber-optical communication systems.