The Performance Comparison of SC-PPM Receiver Models

Abstract

Visible light communication (VLC) technology has arisen as promising candidate to solve the critical challenges of wireless communication networks. In particular, the evolving explosion in use of internet services requiring high bandwidth will soon become a great potential problem among the service provider. Meanwhile, this paper describes a physical layer solution to provide data transmission in the VLC networks. In the paper, it is aim to examine the performance comparison of SC-PPM (Subcarrier Pulse Position Modulation) demodulator schemes. It is considered three receiver techniques to assemble the demodulator techniques to SC-PPM receiver system. Firstly, the traditional PPM (T-PPM) demodulator has been applied on the SC-4PPM receiver system to estimate the slot that includes high frequency signal that is referred to as subcarrier signal. To successfully detect the bits by using traditional PPM receiver, it must be known the dimming level of received SC-4PPM signal. This is a serious problem to ensure data transmission in the real-time VLC systems due to challenge of providing the variable dimming level knowledge at the receiver side. In another receiver model that is referred to as PD (Peak Detector), it is aim to detect peak values of slot with high frequency signal. The disadvantage of this system is that BER (Bit Error Rate) performance depends the difference between peak and bottom values of subcarrier filled slot. Hence, second method is improved to achieve the similar BER performance at all dimming levels between 12.5% and 87.5%. This receiver model is called as IPD in the paper. In brief, it is reported for the first time, it has been employed the PD and the IPD algorithms for the SC-PPM receiver schemes. In addition to this, it is given a theoretical framework for both the traditional PPM and the improved receiver schemes in VLC-SC-PPM schemes. Moreover, it has been investigated how the SC-PPM receiver schemes are affected by brightness level.