A. O. Aldhaibani ¹, S. A. Aljunid ¹, M. S. Anuar ¹, J. M. Nordin ¹

Affiliations
1 Centre of Excellence Advanced Communication Engineering (CoE ACE), Universiti Malaysia Perlis (UniMAP), MY

Abstract

Spectral Amplitude Coding Optical Code Division Multiple Access (SAC-OCDMA) system encounters several challenges because the MultipleAccess Interference (MAI) of the overlapping chips as number of simultaneous users’ increases. Objectives: Our objective is to develop SAC-OCDMA system with OFDM modulation, based on Flexible Cross Correlation (FCC) code to limit the effect of noises. Methods/Analysis: The average received signal to noise ratio (SNR) with the effects of total noise such as Phase Induced Intensity Noise (PIIN), shot noise and nonlinearity of subcarriers is derived. In addition to generated the Numerical analyses of proposed system. Findings: The results have been evaluated based on SNR, PIIN, shot noise and number of users as well as the amount of power received. The results show that the proposed system improve the capacity of system performance in term of users and suppress the system impairments, Furthermore, by using FCC code can effectively reduce the effects of total noise and mitigate the Multiple Access Interference (MAI). Therefore the applying of OFDM modulation with SAC-OCDMA system has been proven to be robust against the MAI and surely enhanced the system performance, in term of SNR and high number of user allocated, compare to SubCarrier Multiplexing (SCM)/ SAC-OCDMA system.

Keywords

Noises, OFDM Modulation, SAC-OCDMA System

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E. A. Alyan ¹, S. A. Aljunid ¹, M. S. Anuar ¹

Affiliations
1 Centre of Excellence Advanced Communication Engineering (CoE ACE), Universiti Malaysia Perlis (UniMAP), MY

Abstract

Objectives: The aim of this paper is to develop an indoor wireless infrared CDMA system based on Zero Cross Correlation (ZCC) code to minimize the effect of noises, and thus improves the overall performance. Methods/ analysis: Two different configurations of 1-cell and 4-cell are investigated. A mathematical framework to calculate the SNR and the BER under the effect of total noise such as LED shot noise, ambient light shot noise and thermal noise, is derived. The system performance is analysed in terms of SNR and BER, versus the width and length of the room, and number of users, respectively, and then compared with the system based on a Flexible Cross Correlation (FCC) code. Findings: The indoor infrared CDMA based on 4-cell configuration using the ZCC code showed better performance than the system based on 1-cell configuration or using the FCC code. As results, the 4-cell configuration based on ZCC could accommodate a larger number of users rate at the corners and edges of the room. It offered 42% and 150% larger cardinality at the edges, and the corners of the room respectively, compared to the 1-cell configuration. In addition, this system also offered 55%, 47%, 51% larger cardinality at the centre, the edges, and the corners of the room, respectively, in contrast to the FCC code. Application/Improvement: The proposed 4-cell configuration based on ZCC code for indoor wireless infrared CDMA system enhances the cardinality, and offers an excellent degree of mobility.

Keywords

FCC Code, Indoor Wireless, Infrared, Multiple Cell Configuratuions, OCDMA, ZCC Code

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