Mitigation of the Memory-Less Nonlinearity Based on Adaptive Technique “Least Mean Square” in Visible Light Communication

The essential design interest for system designers of wireless communication is modeling distortion introduced by the nonlinear behavior of the components integrated in the design. Wireless communication systems usually suffer from the nonlinearity existing in the Visible Light Communication (VLC) front-end, which is produced by the Light Emitting Diode (LED). Nonlinearity is presented as the clipping noise shape at the time-domain signal that mostly results either from Direct Current (DC) in order to ensure that the transmitted data works in the LED's operation region or from physical limitation of the transmitter front-end. The clipping noise can be modeled depending on the Bussgang theorem as diminution of data. In this paper, a mitigation technique is proposed in order to estimate and compensate for the clipped part of the signal at the transmitter, based on Least Mean Square (LMS) algorithm. Then, the impact of LED bias point on the performance of Binary Phase Shift Keying (BPSK) modulation is examined. Finally, different clipping noise Bit Error Rate (BER) performances of DC-BPSK with the mitigation technique and static postdistortion are compared.