A CMOS electronic dispersion compensator for 10-Gbps fibre-optic receivers

A high-speed electronic dispersion compensator (EDC) with adaptation functionality is proposed in this article. Adaptation is needed to adjust the compensation ratio adequately according to the time-varying polarisation-mode dispersion (PMD) which varies relatively slowly and leads to temporal intersymbol interference (ISI) and distortion. Assuming moderate ISI, the adaptation function is based on the modified LMS or sign-data LMS. The EDC is utilised in a 10-Gbps OC-192 fibre-optic receiver. Through removal or alleviation of the ISI, the EDC enables longer repeater-less span and higher data rates or lowered ISI penalty in Gbps-range fibre-optic communication systems. Experimental results are given using a 0.13 µm CMOS process with 1.2 V supply. The power drain of the overall circuitry is on the low side of 16 mW.