Modulo-based Phase Gradient Method for OAM Mode Detection

Phase gradient method (PGM) is a low complexity detection method for orbital angular momentum (OAM). It is sensitive to the location of sampling points due to the phase wrapping, and then lacks in the detection accuracy near the phase discontinuous region, where is denoted as a non-detection zone. This paper proposed a modulo-based PGM (MO-PGM) to translate from non-detection zone to detectable zone by selecting the suitable modulo-factors. The simulation results show that the MO-PGM can improve the average success detection ratio than PGM, especially near the non-detection zone.