SCM-WDM PONs in Presence of XPM and GVD

SCM-WDM PONs in Presence of XPM and GVD

DOI: 10.4018/978-1-4666-6575-0.ch005


In this chapter, a semi-analytical approach is used to evaluate and analyse the performance limitation of a SCM-WDM Passive Optical Network (PON) in the presence of Cross Phase Modulation (XPM) and Group Velocity Dispersion (GVD). In this context, a general expression for electrical average crosstalk noise power due to XPM and GVD was derived to measure the system performance for increasing number of WDM channels. Using the expression, it is found that XPM and GVD causes crosstalk in the system and imposes a power penalty as the WDM channels increases for a given channel spacing and modulating frequency. These results are extended to show that the system can be optimized to achieve a minimum BER of 10-9 by controlling the channel spacing and modulating frequency as the number of WDM channels increases.
Chapter Preview

Theoretical Model

The theoretical analysis is extended from (Wang, 1995; Yang, 2000; Subramaniam, 2005). Consider N optical waves with the same polarization, co-propagating in a single-mode fiber. Assuming each optical wave is modulated with the same single subcarrier, the optical power at the input of the fiber can be expressed as:

(5.1) where k denotes the center channel in an N channel WDM system, with wavelengths {λ1, λ2, λ3λN} and λ1 > λ2 > λ3 > λN . The center channel is evaluated since it represents the worst case. Pb is the average output power of each of the laser; m, ωs, ϕ are, respectively the modulation index, angular frequency and initial phase of the subcarrier. For simplicity, we assume the subcarrier to be unmodulated and ignore the initial phase.

Complete Chapter List

Search this Book: