Research on Suppression of LED Nonlinearity

The high peak-to-average power ratio of orthogonal frequency division multiplexing technique in visible optical communication systems increases the probability of nonlinear distortion of the transmit signal. In order to reduce the BER of the system, an improved nonlinear compensation technique of K-nearest neighbors (KNN) algorithm is proposed. The algorithm takes into account the transmission characteristics of the signal and reduces the impact of uneven distribution of constellation points on the classification efficiency by weighting the training set data based on the number of constellation points within the KNN. The simulation results show that the improved KNN algorithm can effectively solve the nonlinearity problem of visible light communication system and reduce the BER of the system compared with the traditional KNN algorithm.