Performance Comparison between Modified Prime Sequence Codes and Superimposed Optical Cyclic Orthogonal Codes for OCDMA System at 5 Gbps Bit Rate

摘要

In this paper the performance of two coding techniques named Modified Prime Sequence Codes (MPSC) and Superimposed Cyclic Optical Orthogonal Codes (SCOOC) is compared for Optical Code Division Multiple Access (OCDMA) system. A realistic simulation model of OCDMA system is designed for analyzing the performance of these codes. The performance analysis in terms of bit error rate, quality factor is carried out at extremely high bit rates of 5 Gbps. The research shows that both the coding techniques give an improved performance compared to previous researches in terms of quality factor and bit error rate with minimum input requirements of power, bit rate etc for even in case of larger number of users. Results shows that at -15 db received power for permissible BER of 10-9 the MPSC and SCOOC based OCDMA system can accommodate up to 17 and 18 users respectively at 5 Gbps bit rate. For SCOOC based OCDMA system, the bit error rate degrades very slowly as the number of users increases from 2 to 16 but it deteriorates very fast once the number of users goes beyond 18. Also, if the number of users are upto 16 and the received power is more i.e. -15 db then one can choose MPSC based OCDMA system whereas for more number of users as well as for less received power SCOOC based OCDMA system is recommended. So it is advisable to use the high received power system when the bit rate is high i.e. 5 Gbps.