Performance analysis of FSO OFDM for 256-QAM scheme under optical diverse channel
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Arun Kumar
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Devaraju Ramakrishna
Abstract
This study presents a detailed performance evaluation of the proposed free space optical-orthogonal frequency division multiplexing (FSO-OFDM) system compared with conventional schemes such as orthogonal frequency division multiplexing (OFDM), filter bank multi-carrier (FBMC), non-orthogonal multiple access (NOMA), and universal filtered multi-carrier (UFMC) under diverse optical channel conditions. Bit error rate (BER) results in Rayleigh fading channels indicate that the proposed method attains a BER of 10−3 at only 6.2 dB Signal-to-Noise Ratio (SNR), yielding gains of 7.6 dB, 6.2 dB, 5.3 dB, and 3.4 dB over OFDM, FBMC, NOMA, and UFMC, respectively. In Rician fading channels, the same BER is achieved at just 5.4 dB SNR, with improvements of 7.2 dB, 5.8 dB, 4.8 dB, and 3.0 dB compared to the respective schemes. Peak-to-average power ratio (PAPR) analysis at a complementary cumulative distribution function (CCDF) of 10−3 shows a value of 10.8 dB for the proposed system, reducing nonlinear distortions and improving amplifier efficiency. Capacity analysis confirms a peak of 300 units at 50 dB SNR, surpassing all competitors. Power spectral density (PSD) results reveal sidelobe suppression beyond −200 dBW/MHz, with significant out-of-band emission reductions. Overall, FSO-OFDM offers superior robustness, spectral efficiency, and throughput for high-capacity optical communication systems.
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Research ethics: Not Applicable.
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Informed consent: Not Applicable.
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Author contributions: The authors have accepted responsibility for the entire content of this manuscript and approved its submission.
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Use of Large Language Models, AI and Machine Learning Tools: Not Applicable.
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Conflict of interest: The authors state no conflict of interest.
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Research funding: Not Applicable.
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Data availability: Not Applicable.
References
1. Kumar, A, Nanthaamornphong, A, Gaur, N. Optimizing PAPR performance for 6G OTFS waveform using adaptive genetic PTS method for Rician fading channels. EURASIP J Appl Signal Process 2025;2025:22. https://doi.org/10.1186/s13634-025-01234-7.Search in Google Scholar
2. Lain, JK, Wu, SY, Yang, PH. PAPR reduction of OFDM signals using PTS: a real-valued genetic approach. J. Wireless Com. Netw 2011;126:1–8. https://doi.org/10.1186/1687-1499-2011-126.Search in Google Scholar
3. Kumar, A, Nanthaamornphong, A, Alsharif, MH, Masud, M. SIC based RL for massive MIMO NOMA signal detection for different modulation schemes under diverse channel conditions. Sci Rep 2025;15:24641. https://doi.org/10.1038/s41598-025-06492-x.Search in Google Scholar PubMed PubMed Central
4. Kumar, A. Spectrum sensing beyond 5G system: deep learning and conventional techniques analysis. Multimed Tool Appl 2025;84:34681–704. https://doi.org/10.1007/s11042-025-20638-z.Search in Google Scholar
5. Kaur, M, Mohta, A. A review of deep learning with recurrent neural network. In: 2019 International conference on smart systems and inventive technology (ICSSIT). Tirunelveli, India: IEEE; 2019:460–5 pp.10.1109/ICSSIT46314.2019.8987837Search in Google Scholar
6. Rezk, NM, Purnaprajna, M, Nordström, T, Ul-Abdin, Z. Recurrent neural networks: an embedded computing perspective. IEEE Access 2020;8:57967–96. https://doi.org/10.1109/access.2020.2982416.Search in Google Scholar
7. Kumar, A, Nanthaamornphong, A. Genetic algorithm-based PTS with CNN for PAPR and BER reduction in FBMC systems under fading channels. Ain Shams Eng J 2025;16:103434. https://doi.org/10.1016/j.asej.2025.103434.Search in Google Scholar
8. Kanjilal, P, Kumar, A, Bhowmick, S, Maroor, JP, Nanthaamornphong, A. Implementation of companding scheme for performance enhancement of optical OFDM structure. J Opt Commun 2025;46:733–40. https://doi.org/10.1515/joc-2024-0095.Search in Google Scholar
9. Jaiswal, I, Sangeetha, RG, Suchetha, M. Performance of M-ary quadrature amplitude modulation-based orthogonal frequency division multiplexing for free-space optical transmission. IET Optoelectron 2016;10. pp. … (page numbers not visible). https://doi.org/10.1049/iet-opt.2015.0091.Search in Google Scholar
10. Anandkumar, D, Sangeetha, RG. Performance evaluation of LDPC-coded power series based Málaga (Ṁ) distributed MIMO/FSO link with M-QAM and pointing error. IEEE Access 2022;10:62037–55. https://doi.org/10.1109/ACCESS.2022.3180835.Search in Google Scholar
11. Wansu, L. BER analysis of coherent free-space optical systems with BPSK over gamma–gamma channels. J Opt Soc Korea 2015;19:237–40. https://doi.org/10.3807/JOSK.2015.19.3.237.Search in Google Scholar
12. Nistazakis, HE, Stassinakis, AN, Sandalidis, HG, Tombras, GS. QAM and PSK OFDM RoFSO over M-Turbulence induced fading channels. IEEE Photon J 2015;7:1–11. https://doi.org/10.1109/JPHOT.2014.238167.Search in Google Scholar
13. Nistazakis, HE, Stassinakis, AN, Sheikh Muhammad, S, Tombras, GS. BER estimation for multi-hop RoFSO QAM or PSK OFDM communication systems over gamma–gamma or exponentially modeled turbulence channels. Opt Laser Technol 2014;64:106–12. https://doi.org/10.1016/j.optlastec.2014.05.004.Search in Google Scholar
14. Sharma, M, Chadha, D, Chandra, V. Performance analysis of MIMO–OFDM free space optical communication system with low-density parity-check code. Photonic Netw Commun 2016;32:104–14. https://doi.org/10.1007/s11107-015-0579-y.Search in Google Scholar
15. Kumar, A, Gupta, M. A review on OFDM and PAPR reduction techniques. Am J Eng Appl Sci 2015;8:202–9. https://doi.org/10.3844/ajeassp.2015.202.209.Search in Google Scholar
16. Kumar, A, Venkatesh, J, Gaur, N, Alsharif, MH, Jahid, A, Raju, K. Analysis of hybrid spectrum sensing for 5G and 6G waveforms. Electronics 2023;12:138. https://doi.org/10.3390/electronics12010138.Search in Google Scholar
17. Du, C, Huacheng, Z, Wenjing, L, Thomas, H. On cyclostationary analysis of wi-fi signal for direction estimation. In: IEEE mobile wireless network symposium. New York, NY, USA: IEEE; 2015:3557–61 pp.10.1109/ICC.2015.7248876Search in Google Scholar
18. Kumar, A, Rathore, H. Reduction of PAPR in FBMC system using different reduction techniques. J Opt Commun 2021;42:303–9. https://doi.org/10.1515/joc-2018-0071.Search in Google Scholar
19. Kumar, A. A novel hybrid PAPR reduction technique for NOMA and FBMC system and its impact in power amplifiers. IETE J Res 2022;68. https://doi.org/10.1080/03772063.2019.1682692.Search in Google Scholar
20. Kumar, A, Gupta, M, Le, D, Aly, AA. PTS-PAPR reduction technique for 5G advanced waveforms using BFO algorithm. Intell. Automat. Soft Comput 2021;27:713–22. https://doi.org/10.32604/iasc.2021.015793.Search in Google Scholar
21. Chen, S, Zhao, J. The requirements challenges and technologies for 5G of terrestrial mobile telecommunication. IEEE Commun Mag 2014;52:36–43.10.1109/MCOM.2014.6815891Search in Google Scholar
22. Albreem, MA, Kumar, A, Alsharif, MH, Khan, I, Choi, BJ. Comparative analysis of data detection techniques for 5G massive MIMO systems. Sustain 2020;12:9281. https://doi.org/10.3390/su12219281.Search in Google Scholar
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