Realization of real-time DSP for C-band PAM-4 transmission in inter-datacenter network

• DOI: 10.1364/oe.382194
• Publication Date: 2019-12-27T03:00:05Z
• Authors: Sang-Rok Moon; Seung-Woo Lee; In-Ki Hwang; Hun-Sik Kang; Hae Young Rha; Joon Ki Lee
• Keywords: Forward error correction

We designed and realized real-time pulse amplitude modulation-4 (PAM-4) digital signal processing (DSP) including forward error correction (FEC) for a C-band inter-datacenter network. The PAM-4 DSP is intended to compensate chromatic dispersion provide tolerance. A decision feedback equalizer (DFE) maximum likelihood sequence (MLSE) were employed the compensation. low-density parity check (LDPC) code was used increase coding gain. soft-decision Viterbi algorithm (SOVA) adopted probabilistic information LDPC code. For implementation in field programmable gate arrays (FPGAs), we fully parallelized structures. In design, three cores operated parallel, equalizers also with 128 symbols. With DSP, empirically proved feasibility of 25 km transmission without error-floor sign, corresponding compensation capacity 425 ps/nm. confirmed 35 ∼ 85 error-free