Inverse pulse position modulation schemes for simultaneous visible light wireless information and power transfer

In this paper, for constructing flexible underwater wireless sensor network, we discussed an underwater visible light communication system with simultaneous power transfer. For realizing the system, the received optical power is used for both data communication and power transfer, and it is necessary to design the receiver for separating the signal to alternate current (AC) and direct current (DC). We employ the receiver circuit based on low pass filter for DC signal and high pass fileter for AC signal. Moreover, we analyzed the BER performance and power supply performance when the designed AC/DC separation filter is based solar panel is used as the receiver. As a modulation scheme, we consider inverse pulse position modulation (IPPM) which would achieve stable supply of power. As a result, in the BER performances, IPPM show the higher performances compared to OOK. Compared to PPM, the performances for IPPM deteriorated by about 4.78 dB due to the high transmitted power per bit. However, the high transmitted power per bit is important for power supply, and PPM and IPPM show similar BER performances when the same pulse amplitudes of these modulation schemes. In the CV performances, CV of IPPM is improved by 20% compared to OOK and 1.1% compared to PPM with the bit rate of 200 kbps. From these results, IPPM can achieve stable supply of power.