Analytical study of DWDM optical long haul network with symmetrical dispersion compensation

Abstract

Objective: To design 40 Gbps ultra-dense wavelength division multiplexed (DWDM) optical network for 32 and 64 channels. Methods: Proposed DWDM architecture supports three different advance modulation schemes with symmetrical dispersion compensation unit. Performance of proposed work has been investigated using parameters bit error rate (BER) and quality factor. For efficient analysis, we employ variation in channel spacing, transmission length of fiber and input laser power, which is resulted into some significant observations. Findings: Carrier Suppressed Return to Zero (CSRZ) scheme exhibits a good quality factor with maximum achievable distance up to 4250 km due to highest tolerance to nonlin-ear effects. Modified Duobinary Return to Zero (MDRZ) modulation scheme also provides a good quality factor with laser power variation due to high receiver sensitivity, but with limited reach upto 2750 km. While Duobinary Return to Zero (DRZ) scheme provides moderate transmission coverage up to 3750 km in comparison to CSRZ and MDRZ, with a lesser quality factor due to effect of Inter Symbol Interference (ISI). We observe that an increase in number of simultaneous users through the channels results into performance degradation. Application: This work delivers very huge data rate and good spectral efficiency to sustain the current high traffic growth.