Saied, OsamaGhassemlooy, ZabihZvanovec, StanislavKizilirmak, Refik CaglarLin, Bangjiang2022-07-192022-07-192020Saied, O., Ghassemlooy, Z., Zvanovec, S., Kizilirmak, R. C., & Lin, B. (2020). Unipolar-pulse amplitude modulation frequency division multiplexing for visible light communication systems. Optical Engineering, 59(09). https://doi.org/10.1117/1.oe.59.9.096108http://nur.nu.edu.kz/handle/123456789/6452Asymmetrically clipped optical orthogonal frequency division multiplexing (ACO OFDM) has been proposed in visible light communication (VLC) systems to overcome the dc-biased optical OFDM power consumption issue at the cost of the available electrical spectral efficiency. Due to the implementation of inverse fast Fourier transform, all the optical OFDM schemes including ACO-OFDM suffer from large peak-to-average power ratio (PAPR), which degrades the performance in VLC systems as the light-emitting diodes used as the transmitter have a limited optical power-current linear range. To address the PAPR issue in ACO-OFDM, we introduce a unipolar-pulse amplitude modulation frequency division multiplexing by adopting the single carrier frequency division multiple access (SC-FDMA). This is achieved by consid ering a PAM as an SC-FDMA data symbol and inserting a conjugate copy of the middle and first SC-FDMA FFT output subcarriers after the middle and last subcarriers, respectively. Simulation results show that, for the proposed scheme, the PAPR is 3.6 dB lower compared with ACO OFDM. The PAPR improvement is further analyzed with the simulation results demonstrating that the proposed scheme offers 2.5 dB more average transmitted power compared to ACO OFDMenAttribution-NonCommercial-ShareAlike 3.0 United StatesType of access: Open Accesssingle carrier frequency division multiple accessasymmetrically clipped optical orthogonal frequency division multiplexingpeak-to-average power ratiolight-emitting diodedynamic rangeArticle