Performance Analysis of Optical CDMA systems with PPM Signaling

Abstract- An optical code-division multiple-access (OCDMA) system with M-ary pulse-position modulation (PPM) signaling is investigated. Latin-Square based optical orthogonal codes (OOCs) are proposed to be used in conjunction with modified prime codes as address sequences in our system. A union lower bound on the bit error rate (BER) is derived and the performance characteristics are then discussed with a variety of system parameters. In the presence of multiuser interference (MUI) and receiver shot noise, our results show that the performance, in terms of the BER, of the proposed system is significantly improved by PPM coding compared with that of the system with unmodulated signaling. Key Words: Optical code-division multiple access (OCDMA), pulse-position modulation (PPM), Latin Square, optical orthogonal codes (OOCs), modified prime codes, bit error rate (BER), multiuser interference (MUI). I