Vol. 41, Issue 1, pp. 173-181

Abstract

In this paper, we will focus on the modulation format used to create the optical pulses, which are return-to-zero (RZ), and non-return-to-zero (NRZ). Bit error rate (BER) performance is evaluated based on double weight (DW) code. Optical code division multiple access (OCDMA) system is considered a promising technique for fiber-to-the-home (FTTH) access networks. The performance of RZ against NRZ is compared through simulation by using the Optisystem software version 7. We used two networks designed as follows: one used a RZ pulse generator and the second used a NRZ pulse generator, and both systems were tested with and without erbium doped fiber amplifier (EDFA). It has been found that the NRZ pulse generator in this system is better than the RZ pulse generator for all simulation results. The conversion used a Mach–Zehnder interferometer (MZI) wavelength converter. Also, we are proposing a detection scheme known as the AND subtraction detection technique implemented with fiber Bragg grating (FBG) which acts as an encoder and decoder. This FBG is used to encode and decode the spectral amplitude coding DW code in the OCDMA system. The performances are characterized through BER and bit rate (BR), and also the received power at various bit rates.