Study on the QC-LDPC code in optical communication system based on the FOPA
Zheng Jia · Journal of Optoelectronics·laser · 2014
Optical signal would be distorted during transmission in fiber caused by dispersion,and the nonideal optical amplification would also lead to error bits.In order to restrain the effects,in this paper,quasi-cyclic low density parity check(QC-LDPC)codes are studied in a 40Gbit/s non-return-to-zero differential phase shift lceying(NRZ-DPSK)signal transmission system based on fiber-based optical parametric amplification(FOPA)so that the performance of the optical communication system could be improved.The results indicate that under 10km fiber length,the bit error rate(BER)can achieve 10-11because of the QC-LDPC codes with the same code length but different code rates,and then the different fiber lengths are tested for the same QC-LDPC codes,the BERcan achieve 10-11 also.QC-LDPC codes constructed by the maximization of the shortest cycle algorithm can correct the bits errors caused by dispersion,nonlinearity,and pump jitter,and consequently the communication quality can be improved.