IP Routing and Transmission Analysis in Optical CDMA Networks: Coherent Modulation With Incoherent Demodulation

A novel Internet protocol (IP) transmission and routing is proposed over coherent multiple array (M-ary) frequency shift keying optical code-division multiple-access (FSK-OCDMA) network with incoherent demodulation. The architecture also benefits from the use of the co-channel interference canceller. In contrast to wavelength-division multiple-access (WDMA), a fewer set of wavelengths are needed as a result of M-ary source coding. As the spreading codes, double-padded modified prime codes (DPMPC) have been employed. The performance has been analyzed in terms of the users´ channel utilization in the network and compared with common incoherent pulse-position modulation technique. The results indicate that this architecture is very power efficient and enhances the network capacity. With the advantage of shorter code length, DPMPC also improves the throughput. It is shown that for a maximum bit-rate, the network performance can be improved by reducing the channel utilization. Since each IP packet is buffered only at the edge of this network, the buffer delay is considerably reduced. The novel encoder adjusting time management reduces the switching time notably rather than traditional routing. Our analytical investigation clearly indicates that this OCDMA technique can be an excellent candidate for the future ultra-fast high bit-rate optical IP networks.