Conference:
Proceedings of the 8th WSEAS International Conference on Microelectronics, Nanoelectronics, Optoelectronics (MINO)
Proceeding Volume:
8
Location:
Istanbul-Turkey
Date:
Saturday, May 30, 2009
Abstract:
Performance of optical code division multiple access (O-CDMA) system is influenced by multiple
access interference (MAI) resulted from the overlapping between the users. To overcome this problem, successive
interference cancellation (SIC) scheme is applied to O-CDMA systems. In this paper we apply successive
interference cancellation technique to a spectral amplitude coding (SAC) system that uses modified quadratic
congruence (MQC) codes as signature sequence codes. The system is analyzed for two cases: same effective power
for all the users and different effective power from each user. It is shown that under ideal effective power the
SIC/SAC optical CDMA systems have potential to suppress the intensity noise and mitigate multiple access
interference. Hence, using SIC/SAC cancellation scheme, the system can accommodate much more number of
users as compared to the one without cancellation. Further, under ideal power the system using SIC scheme with
direct sequence encoding (SIC/DS) shows much lower BER performance as compared to the one without
cancellation (i.e. conventional receiver) or to SIC/SAC cancellation scheme. Hence, much more number of users
can be accommodated by SIC/DS receiver system. Furthermore, SIC/DS scheme still shows much lower BER
performance as compared with SIC/SAC scheme under different effective power.
Attachments:
