On the Achievable Performance in the presence of Multiple Path Interference for Intra Data Center applications

An accurate analytical form of the achievable bit error rate in the presence of multipath interference (MPI) is proposed for PAM4 for the first time, taking into account an ideal MPI estimate and compensation.

Classification of MIMO Equalizers

In this theoretical work, the DSP-perceived channel in optical coherent communications is first simplified, based on which we categorize linear MIMO equalizers into four classes according to their reference locations. The entire channel inverse can be represented by a complex conjugate-dependent system, coinciding with the widely linear equalization theory. Suboptimally removing FO dynamics, relatively static channel inverses parameterized with common device and channel parameters are presented for monitoring or calibration purposes.

Transmitter IQ Skew Calibration using Direct Detection

We propose a transmitter skew calibration based on direct detection of coherent signals with estimation errors of +/-0.2ps, providing a reliable, accurate and low-cost scheme to calibrate skew for coherent transceivers. In October 2019, this work was submitted / was exposed to Optical Fiber Communication Conference 2020 but an acceptance was not granted. We claimed the first time to use a direct detection-based feedback method for coherent transmitter calibration.