Time-Domain Digital Back Propagation for Optical Communication in 28 nm FD-SOI

Abstract

Compensation for signal impairments caused by optical fibers are essential for the communication system when transfering data. Two major impairments are chromatic dispersion and nonlinearities and today these are often compensated for with two separate systems. Digital back propagation is a method used for compensating for both kinds of impairments and, if used in the time domain, it can be implemented in hardware. We have investigated the possibilities of implementing this method in an application specific integrated circuit (ASIC) fabricated in a 28nm silicon-oninsulator process. Simulations have been done in MATLAB and the design has been implemented with a hardware description language. The conclusion reached is that it is achievable to compensate for both dispersion and nonlinearities with an ASIC of approximately 1mm2 at a lower symbol rate and it can be run at a full speed with a larger ASIC area. The achieved bit error rate is 0.007 when compensating for impairments accumulated over 4000km which is an acceptable result.