Kramers–Kronig receivers

This paper reviews the foundations of the Kramers–Kronig (KK) receiver, a recently proposed scheme designed to reconstruct a complex-valued signal from the measurement of its intensity in the context of fiber-optic communications. We provide a comprehensive characterization of the signal properties that are required for the proper operation of the KK receiver and discuss the most relevant implementation requirements, such as the need for digital up-sampling, the implications of receiver imperfections, line chromatic dispersion, optical filtering, and polarization multiplexing.