No abstract

challenge. This paper outlines the challenge, its organization, the dataset used, evaluation methods and results of top performing participating solutions. We observe that the top performing approaches utilize a blend of clinical information, data augmentation, and the ensemble of models. These findings have the potential to enable new developments in retinal image analysis and image-based DR screening in particular.

In a visible light communication (VLC) system, the light-emitting diode (LED) is the major source of nonlinearity. The nonlinear effects in the VLC system are different from the conventional wireless communications system. The channel separation in the VLC system is significantly larger than the signal bandwidth; thus, the adjacent channel interference is not an issue. Predistortion technique may not be a cost-efficient approach since it needs additional feedback physical circuits at the transmitter. In this paper, we propose a postdistortion technique to estimate and compensate for the LED's nonlinearity at the receiver. The postdistortion technique only needs some additional computational resources. In addition, the proposed approach significantly improves the error-vector-magnitude and bit-error-rate performance of the VLC system. Simulation results validate the theoretical analysis.