Digital filters for coherent optical receivers

Compact Optical Receivers for Coherent Optical Communication

Communication traffic is increasing continuously along with the expansion of video streaming service and the popularization of smartphones and other mobile devices requiring high-speed, large-capacity transmission. Digital coherent optical communication technology using multilevel modulation formats has already been used for long haul systems and is now attracting attention as a means of long-d...

Robust Matched Filters for Optical Receivers

Phase Diversity Techniques for Coherent Optical Receivers

Abstruct-In the present state of the art, coherent optical receivers most often operate in the heterodyne mode. Here a photodiode-,amplifier combination having bandwidth greater than twice the bit rate ( B ) is needed: indeed bandwidths considerably greater than 2B are preferably employed to ease design of the bandpass filter needed for noise limitation, and to avoid demodulator penalties in so...

Multi-aperture digital coherent combining for free-space optical communication receivers.

Space-to-ground optical communication systems can benefit from reducing the size, weight, and power profiles of space terminals. One way of reducing the required power-aperture product on a space platform is to implement effective, but costly, single-aperture ground terminals with large collection areas. In contrast, we present a ground terminal receiver architecture in which many small less-ex...

Joint Demapping and Decoding for DQPSK Optical Coherent Receivers

We present a low-complexity joint demapper-decoder scheme for coherent optical receivers with DQPSK modulation. The new technique reduces to 0.7dB the gap between QPSK and DQPSK in 100Gb/s coherent optical systems.