- Optical communications is currently undergoing a real technological revolution based on coherent detection. In addition to preserving the phase information of the optical field, in coherent detection the optical channel becomes a linear system, enabling full compensation of optical fiber impairments by the use of digital signal processing techniques. Here, a coherent transmission and reception scheme for ultra-high data rates (100G and above), adopting advanced modulation formats is presented. In turn, symbol rate sampling followed by antialiasing filtering and digital signal processing is applied. This allows reducing the analog to digital conversion rate which forms one of the major bottlenecks at 100G and above data rates.