LLWT based optical OFDM design with M-CSK module

With the development of technology, the size and traffic of data increase with the increase in population. In the communication sector, efforts have been accelerated to remove this burden, but due to the limited bandwidth and license status of RF technology, the search for different new technologies has increased in importance. Visible light communication (VLC) is emerging as a complementary technology or an alternative technology to radio frequency (RF) communication systems. The visible light spectrum has a frequency range almost 10000 times larger than the radio frequency spectrum. Due to its wide spectrum, resistance to electromagnetic interference, and reliability, it has become the focal point of 6G and beyond studies. Orthogonal frequency division multiplexing (OFDM) will be the best option for super-fast optical radio communication (OWC) due to its resistance to inter-symbol interference (ISI), as in RF communication. Asymmetrically clipped optical OFDM (ACO-OFDM), DC bias coupled optical OFDM (DCO-OFDM), and Flip-OFDM, which have been adapted for intensity modulation/direct detection (IM/DD) systems, are the approved polarisation OFDM schemes mentioned in the literature for OWC. In this paper, to improve the performance of ACO-OFDM, DCO-OFDM, and Flip-OFDM proposed for OWC systems and ZT-DFT-OFDM, which has been widely used in 5G and beyond, in optical systems, it is proposed to combine the Lifting wavelet transform (LLWT) using the Lazy wavelet with these four optical OFDM waveforms. In addition, VLC systems are faced with a disadvantage such as jitter issues despite the many advantages mentioned above. There are many pieces of research in the literature to eliminate this disadvantage. Within the scope of this proposed master's thesis, as stated in the IEEE 802.15.7 standard, the results are compared by computer simulations in AWGN channel environment for bit error rate (BER) and peak average power ratio (PAPR) benchmarking criteria in the environment where M-level color shift keying (M-CSK) and M-level quadrature amplitude modulation (M-QAM) modulations are used. From the simulation results, it is observed that the proposed waveforms provide better performance in both M-CSK and M-QAM modulations. It is also observed that the Lazy Lifting Wavelet Transform contributes to both modulation types and Optical-OFDM systems.