Fiber based optical parametric amplif ier for 40 Gb/s NRZ DPSK signal transmissi

In this letter, we investigate quasi-cyclic low-density parity-check (QC-LDPC) codes in a 40-Gb/s nonreturn-to-zero differential phase-shift keying (NRZ-DPSK) signal transmission system based on a fiber-based optical parametric amplifier (FOPA). A constructed algorithm of QC-LDPC codes according to