A Novel Transceiver Model for Polar Transform Optical (PTO-) OFDM for Visible Light Communication (VLC) Based on Peak to Average Power Ratio Reduction using Precoding
Oumar Sacko1, Stephen Musyoki2, Vitalice K. Oduol3

1Oumar Sacko*, Telecommunication Program, Pan African University Institute for Basic Sciences Technology, and Innovation (PAUISTI), Jomo Kenyatta University of Agriculture and Technology (JKUAT), Nairobi, Kenya.
2Stephen Musyoki, Dept. of Telecommunication and Information Engineering of organization, The Technical University of Kenya (TUK), Nairobi, Kenya.
3Vitalice K. Oduol, Dept. of Electrical & Information Engineering, University of Nairobi (UoN), Nairobi, Kenya.
Manuscript received on July 23, 2020. | Revised Manuscript received on August 05, 2020. | Manuscript published on August 10, 2020. | PP: 307-315 | Volume-9 Issue-10, August 2020 | Retrieval Number: 100.1/ijitee.E9914069520 | DOI: 10.35940/ijitee.E9914.0891020
Open Access | Ethics and Policies | Cite | Mendeley
© The Authors. Blue Eyes Intelligence Engineering and Sciences Publication (BEIESP). This is an open access article under the CC-BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/)

Abstract: Indoor visible light communication (VLC) has the potential of providing high data rates for short-range wireless communication with a relative spatial elevated security in contrast to a radiofrequency wireless one. To support that high data stream, Orthogonal Frequency Division Multiplexing (OFDM) is used; however, due to the limited operational bandwidth of the commercial white light-emitting diode (LED), signal processing techniques are used to increase the efficiency of the OFDM and to adapt OFDM to VLC systems. As a major concern, the intensity modulation direct detection necessary for VLC requires positive real signal, this is dealt with by imposing Hermitian pre-possessing or Cartesian to polar conversion post-processing to the OFDM. The use of the Cartesian to polar converter allows the transmission of complex OFDM symbols through the intensity modulation channel. A polar transform optical (PTO-) OFDM presented here as an improvement and simplification of previous polar optical OFDM schemes gives an efficient transceiver architecture. Nevertheless, both OFDM transmission techniques for Visible optical links, similar to radiofrequency (RF), suffer greatly from irregular excessive Peak-to-Average power ratio (PAPR). Higher PAPR reduces the power efficiency of the On-Off Keying (OOK) based on pulse amplitude modulation (PAM). Furthermore, it also is recommendable to reduce the PAPR for conformity with eye safety. A precoding technique is proposed to reduce the PAPR of intensity-modulated for direct detectability of the OFDM signal destined for the wireless optical link using Cartesian-to-Polar conversion. Based on the enhanced processing at the front ends and using MATLAB simulation, it is proven that the presented model can improve the link parameters including the bit error rate (BER) and signal to noise ratio (SNR) and bandwidth efficient compared to Hermitian modified ones. 
Keywords:  Intensity modulation Direct detection, PAPR precoding, Polar Transform Optical OFDM, Pulse Coded Modulation, Visible light communication.
Scope of the Article: IoT Application and Communication Protocol