Anuar Mat SAFAR^*, Syed Alwee ALJUNID, Amir Razif ARIEF, Junita NORDIN, and Naufal SAAD¹

School of Computer and Communication Engineering, Universiti Malaysia Perlis, 02600 Arau Perlis, Malaysia ¹School of Electric and Electronic Engineering, Universiti Teknologi Petronas, 31750 Tronoh, Perak, Malaysia

(Received April 22, 2011; Revised September 22, 2011; Accepted October 21, 2011)

The use of minimal multiple access interference (MAI) in code design is investigated. Applying a projection and mapping techniques, a code that has a zero cross correlation (ZCC) between users in optical code division multiple access (OCDMA) is presented in this paper. The system is based on an incoherent light source — LED, spectral amplitude coding (SAC), and direct detection techniques at the receiver. Using power spectral density (PSD) function and Gaussian approximation, we obtain the signal-to-noise ratio (SNR) and the bit-error rate (BER) to measure the code performance. Making a comparison with other existing codes, e.g., Hadamard, MFH and MDW codes, we show that our code performs better at BER 10^-9 in terms of number of simultaneous users. We also demonstrate the comparison between the theoretical and simulation analyses, where the results are close to one another.

Key words: multiple access interference, spectral amplitude coding, optical code division multiple access, zero cross correlation code

^*E-mail address: anuarms@unimap.edu.my