Suppression of inter and intra channel four wave mixing effects in optical CDMA over DWDM hybrid system

Hybrid optical CDMA and DWDM system implemented under the influence of Non-linear effects

“…The signals are transmitted over 90km of SMF and 15.075km of DCF. According to our previous work [24], the best performance of the proposed system when the transmitted power is 18dBm, beyond this value the system performance significantly decreases because of the effect of the intra FWM. In this work, the amplified spontaneous emission (ASE) is neglected in order to have some insight on FWM effects.…”

“…Therefore, 60 optical CDMA users can be accommodated by the proposed hybrid system; the implemented parameters are summarized in Table 1. It has been shown in [24] that the ISI can be mitigated as the interval of the signature optical code is squeezed into 25% of the bit duration; therefore, such interval is considered in our proposed hybrid system. Figure 2 shows the average BERs versus the transmitted power for the five DWDM channels where each channel carries 12 optical CDMA users at data rate of 5Gb/s/user.…”

Performance Comparison of Different Modulation Formats for a 40 Gbps Hybrid Optical CDMA/DWDM System against ISI and FWM

“…Further details about the function of EOPM are reported in ref. [19]. The output of the EOPM is then launched into single mode fiber + dispersion compensating fiber (SMF + DCF) followed by a preamplifier to compensate the loss.…”

“…Recently, a hybrid optical CDMA/DWDM system considering the effects of inter-and intra-channel FWM and inter-symbol interference (ISI) was proposed [19]. The analysis revealed that the generated inter-channel FWM effect contributes not only as an additional crosstalk component, but also produces other noise terms, namely, signal-FWM, Multiple Access Interference (MAI-FWM), and FWM-FWM noise.…”

“…It has been shown that the CDMA technology, where the bit's energy is spread over the identification code sequence, could minimize the effect of inter-channel FWM. In addition, the electro-optic phase modulator (EOPM) is used to suppress the intra-channel FWM effect in the hybrid optical CDMA/DWDM system [19].…”