Construction of Quasi-Cyclic Low-Density Parity-Check Codes to Combat Optical CDMA Interference Noise

摘要

In spectral amplitude coding optical code-division multiple access (SAC-OCDMA) systems, phased-induce intensity noise (PIIN) is the main noise source which degrades the system performance severely and ultimately limit the number of active users. To reduce the effect of PIIN, we apply the error correction codes to SAC OCDMA systems. This paper is concerning with investigating the performance of quasi-cyclic low-density parity-check (QC-LDPC) code for SAC-OCDMA networks, and it’s easy to implement by using simply shift-registers due to the quasi-cyclic properties of QC LDPC. Moreover, it has been shown that not only the BER performance can be greatly improved, but also a good coding gain can obtained.