The article proposes a method for monitoring the peak-to-average power ratio (PAPR), and also discusses the results of assessing the sensitivity of optical-OFDM systems to phase-frequency distortions. The results of a study of the noise immunity of an optical-OFDM system for frequency shift relative to the spacing of optical subcarriers are presented. A description of the factors causing interference and frequency-phase distortions caused by chromatic dispersion (CD) and polarization mode dispersion (PMD) on the performance of optical multiplexing systems with orthogonal frequency division is carried out. Monitoring the PAPR in OFDM systems is relevant, in particular, in the context of fiber optic communication problems that are caused by the nonlinearity of the optical fiber. It is shown that when directly deploying optical networks, the presence of frequency distortions and sensitivity to phase noise are the two main disadvantages of OFDM. Both frequency distortion and phase noise lead to interchannel interference (ICI). Due to the relatively large symbol length compared to a single carrier, OFDM is susceptible to both frequency distortion and phase noise. An additional cumulative distribution function is used for a visual description of PARP. The effect of the oversampling coefficient on the PARP value is determined. It is proposed to use the oversampled signal to obtain a more accurate PARP value. The results of the study show that the effect of phase noise on a signal in optical OFDM channels is due to the existing long symbol period compared to signal transmission on a single carrier. In addition, with an increase in the modulation order, optical OFDM becomes more sensitive to phase noise, which encourages an increase in the signal-to-noise ratio to counteract this. The results of the research showed that for coherent OFDM optical systems, the line width of the optical quantum generator is a critical parameter, especially when switching to high-order modulation. The paper discusses a diagram describing the process of convergence of radio and optical technologies in the context of the use of OFDM modulation. This technique allows for the correct choice of channel multiplexing strategy in optical OFDM telecommunications with multi-position signals.
[1] Kumar, V. and Mehta, N. B. (2019), "Modeling and Analysis of Differential CQI Feedback in 4G/5G OFDM Cellular Systems," IEEE Transactions on Wireless Communications, vol. 18, no. 4, pp. 2361- 2373. http://doi.org/10.1109/TWC.2019.2903047.
[2] Al-Rubaye, G. A. (2023), "Performance of 5G NR-polar QAM-OFDM in nonlinear distortion plus Non-Gaussian noise over Rayleigh fading channel," AEU – Intern. J. of Electron. and Commun., vol. 171, pp. 154929, https://doi.org/10.1016/j.aeue.2023.154929.
[3] Wang, S., Thompson, J. S. and Grant, P. M. (2017), "Closed-Form Expressions for ICI/ISI in Filtered OFDM Systems for Asynchronous 5G Uplink," IEEE Transactions on Communications, vol. 65, no. 11, pp. 4886- 4898, https://doi.org/10.1109/TCOMM.2017.2698478.
[4] Al-Habashna, A., Dobre, O. A., Venkatesan, R. and Popescu, D. C. (2012), "Second-Order Cyclostationarity of Mobile WiMAX and LTE OFDM Signals and Application to Spectrum Awareness in Cognitive Radio Systems," IEEE Journal of Selected Topics in Signal Processing, vol. 6, no. 1, pp. 26-42, http://doi.org/10.1109/JSTSP.2011.2174773.
[5] Jing, Q., Cheng, M., Lu, Y., Zhong, W. and Yao, H. (2014), "Pseudo-noise preamble based joint frame and frequency synchronization algorithm in OFDM communication systems", Journal of Systems Engineering and Electronics, vol. 25, no. 1, pp. 1-9, https://doi.org/10.1109/JSEE.2014.00001.
[6] Pyatin, I., Boiko, J., Eromenko, O. and Parkhomey, I. (2023), "Implementation and analysis of 5G network identification operations at low signal-to noise ratio", TELKOMNIKA (Telecommunication Computing Electronics and Control), vol. 21, no. 3, pp. 496-505, http://doi.org/10.12928/telkomnika.v21i3.22893.
[7] Boiko, J., and Pyatin, I. (2023), "Circuitry aspects of providing synchronization conditions in communication systems with OFDM", Measuring and computing devices in technological processes, no.1, pp. 28–37. https://doi.org/10.31891/2219-9365-2023-73-1-5.
[8] Mohammed, A., Ismail, T., Nassar, A. and Mostafa, H. (2021), "A Novel Companding Technique to Reduce High Peak to Average Power Ratio in OFDM Systems", IEEE Access, vol. 9, pp. 35217-35228. https://doi.org/10.1109/ACCESS.2021.3062820.
[9] Nunes, R. B., Bacalhau, J. M.R., Silva, J. A.L. and Segatto, M. E.V. (2017), “A MAC layer protocol for a bandwidth scalable OFDMA PON architecture”, Computer Communications, vol. 105, pp. 145-156. https://doi.org/10.1016/j.comcom.2017.01.016.
[10]Fang, X. et al. (2023), "Combined intra symbol frequency domain averaging channel estimation for polarization division multiplexed coherent optical OFDM/OQAM systems", Optical Fiber Technology, vol. 81, pp. 103577. https://doi.org/10.1016/j.yofte.2023.103577.
[11]Pidvyshchennia efektyvnosti optychnykh transportnykh system [Tekst] : dys... d-ra tekhn. nauk: 05.12.02 / Klymash Mykhailo Mykolaiovych ; Natsionalnyi un-t "Lvivska politekhnika". - Odesa., 2007. - 310 ark. - ark. 255-275.
[12]Klymash, M.M., Chernykhivskyi, Ye.M., Oleksin M.I. Poliaryzatsiino-modova dyspersiia optychnykh volokon transportnykh merezh. Vyd. UAD, Lviv, 2007.
[13]Astrakhantsev, A. A., Onyshchenko, Yu. V. (2010), “Estimation of parameters of transmission quality of the information in fiber-optical transmission systems”, Eastern-European Journal of Enterprise Technologies, vol.4, no. 9(46), pp. 74–77. https://doi.org/10.15587/1729-4061.2010.3046.
[14]Ferreira, M. F. S. (2022), Fiber Dispersion and Nonlinearity, Solitons in Optical Fiber Systems, Wiley.
[15]Ono, H. and Yamada, M. (2024), "Gain Dynamics of Few-Mode Erbium-Doped Fiber Amplifier", IEEE Photonics Technology Letters, vol. 36, no. 7, pp. 500-503. https://doi.org/10.1109/LPT.2024.3370940.
[16]Boiko, J, Novikov, D. (2021), “Evaluation of channel coding efficiency in OFDM telecommunications”, Herald of Khmelnytskyi national university, iss. 5, pp. 150-159. https://www.doi.org/10.31891/2307-5732-2021-301-5-150-159.
[17]Han, X., Huo, B., Shao, Y. and Zhao, M. (2017), "Optical RF Self-Interference Cancellation by Using an Integrated Dual-Parallel MZM", IEEE Photonics Journal, vol. 9, no. 2, pp. 1-8. https://doi.org/10.1109/JPHOT.2017.2690944.
[18]Boiko, J., Eromenko, O., Kovtun, I. and Petrashchuk, S. (2018), "Effectiveness Improvement Method for Signal Processing in Optical Telecommunication", 2018 IEEE International Scientific-Practical Conference Problems of Infocommunications. Science and Technology (PIC S&T), Kharkiv, pp. 777-782. https://doi.org/10.1109/INFOCOMMST.2018.8631895.
[19]Boiko, J., Eromenko, О., and Huriev, О. (2023), "Capabilities of LDPC codes to improve the productivity of optical telecommunications with OFDM", Measuring and computing devices in technological processes, no. 4, pp. 13–26. https://doi.org/10.31891/2219-9365-2023-76-2.
[20]Makarenko, A., Qasim, N. H., Turovsky, O., Rudenko, N., Polonskyi, K., and Govorun, O. (2023), "Reducing the impact of interchannel interference on the efficiency of signal transmission in telecommunication systems of data transmission based on the OFDM signal," Eastern-European Journal of Enterprise Technologies, vol. 1, no. 9, pp. 82-93. https://doi.org/10.15587/1729-4061.2023.274501.