Performance of multicode direct-detection optical CDMA systems

We analyze the performance of multicode direct-detection optical code-division multiple-access (CDMA) systems supporting several kinds of data with different bit rates: each user is assigned a set of sequence codes generated from time-shifted versions of optical orthogonal codes (OOCs). We analyze the performance of multicode direct-detection optical CDMA systems by using the mean value of the maximum cross-correlation between a sequence code and a set of sequence codes. We evaluate the performance of the systems under a fixed bit rate for each sequence code. Our results show that the multicode direct-detection optical CDMA system can support several kinds of data with different bit rates in optical fiber networks. Moreover, we show that the multicode direct-detection optical CDMA system has a better performance than a system using one sequence code for each user at the same bit and chip rates.