Modulation Format Recognition for Optical Signals Using Connected Component Analysis

We investigate and characterize the blind modulation format recognition method based on connected component analysis for general-purpose optical receivers. A converted binary graph is generated by projecting a part of the received data in Stokes space onto a 2-D plane. We further characterize three key parameters, namely, the threshold of density filter, the size of averaging filter, and the required number of data points for successful format recognition. In addition, we compare the computation complexity of the proposed method with other format recognition methods in Stokes space. Our results show that there exists a common set of parameters such that the proposed method can recognize a number of common optical modulation formats, proving its good robustness and practicality.