Kramers–Kronig coherent receiver

The interest for short-reach links of the kind needed for inter-data-center communications has fueled in recent years the search for transmission schemes that are simultaneously highly performing and cost effective. In this work we propose a direct-detection coherent receiver that combines the advantages of coherent transmission and the costeffectiveness of direct detection. The working principle of the proposed receiver is based on the famous Kramers-Kronig (KK) relations,and its implementation requires transmitting a continuous-wave signal at one edge of the information-carrying signal spectrum. The KK receiver scheme allows digital postcompensation of linear propagation impairments and,as compared to other existing solutions,is more efficient in terms of spectral occupancy and energy consumption.