Abstract

A hybrid spectrally amplitude coded (SAC) optical code division multiple access (CDMA) with subcarrier multiplexing (SCM) scheme is a potential candidate for future broadband access solutions in the communication network. In this work, the performance of hybrid technique is investigated. Theoretical derivations are developed based on the zero cross correlation (ZCC) code. The performances are evaluated taking into account the relevant noises such as thermal noise, shot noise and inter modulation noise. Design parameters such as number of optical channels, number of subcarriers, and input power are varied to see their effect on the system performances. Simulation analysis using Optisys simulator is also done and compared to the numerical theoretical results. We measured the performance based on the merits of received power, input power and bit error rates of the received signals. Results revealed that power penalty due to increased number of channels in the hybrid system is lower compared to the conventional OCDMA system, and hence improving the system performance in term of power efficiency. This exhibits the ability of the hybrid system to be one powerful technique as a candidate for future access network.

Key words: Spectral amplitude coding-optical code division multiple access (SAC-OCDMA), subcarrier multiplexing (SCM), zero cross correlation (ZCC), broadband access network.