Experimental Study of a Transmission System Based on FBMC/OQAM

Introduction. This paper investigates a transmission system based on FBMC/OQAM multiplexing. This system is characterized by a high spectral efficiency, thereby attracting interest as an alternative transmission method in future wireless mobile communication standards. However, a disadvantage of the system is the high complexity of signal processing. There are numerous publications that study the FBMC/OQAM system from a theoretical perspective. This paper presents an experimental study of a transmission system based on FBMC/OQAM.

Aim. Verification of a transmission system based on FBMC/OQAM multiplexing in a wireless channel.

Materials and methods. Computer simulation modeling in Matlab and experimental research using Keysight and Rohde & Schwarz certified measuring instruments.

Results. A model of synthesis and signal processing was developed, and a frame structure was proposed. The processing included synchronization, since the study was carried out in a wireless double-dispersive channel. Time synchronization was provided by the method of time-domain correlation. A preamble consisting of two symbols was used for CFO compensation. Channel estimation in FBMC/OQAM was conducted by pilot symbols spread over the time-frequency domain, a method with an auxiliary pilot to compensate for intrinsic interference, as well as Zero Forcing and a linear interpolator. As a result, dependences of the bit error rate on the Eb/N0 in various channels were obtained. An error rate of 10−4 was achieved under the Eb/N0 equal to 13.4 dB, 15.3 dB and 20.9 dB in the first, second and third channel, respectively.

Conclusion. A FBMC/OQAM-based transmission system with a linear equalizer can operate without a cyclic prefix in a multipath wireless channel, providing comparable noise immunity to OFDM-CP. Long frames should be used to obtain greater spectral efficiency, due to the presence of a transition zone at the beginning and end of the FBMC/OQAM frame.

1. Siohan P., Siclet C., Lacaille N. Analysis and design of OFDM/OQAM systems based on filterbank theory. IEEE transactions on signal processing. 2002, vol. 50, no. 5, pp. 1170–1183. doi: 10.1109/78.995073

2. Bolcskei H., Duhamel P., Hleiss R. Design of pulse shaping OFDM/OQAM systems for high data-rate transmission over wireless channels. 1999 IEEE Intern. Conf. on Communications. Vancouver, Canada, 6–10 June 1999, vol. 1, pp. 559–564. doi: 10.1109/ICC.1999.768001

3. Bellanger M., LeRuyet D., Roviras D. et al. FBMC physical layer: a primer. PHYDYAS. 2010, vol. 25, no. 4, pp. 7–10.

4. Hidalgo Stitz T. Filter Bank Techniques for the Physical Layer in Wireless Communications. Tampere, Tampere University of Technology, 2010, 178 p.

5. Yunzheng T., Long L., Shang L., Zhi Zh. A survey: Several technologies of non-orthogonal transmission for 5G. China communications. 2015, vol. 12, no. 10, pp. 1–15. doi: 10.1109/CC.2015.7315054

6. Schaich F., Wild T. Waveform contenders for 5G – OFDM vs. FBMC vs. UFMC. 2014 6th Intern. Symp. on Communications, Control and Signal Processing (ISCCSP). Athens, Greece, 21–23 May 2014. IEEE, 2014, pp. 457–460. doi: 10.1109/ISCCSP.2014.6877912

7. Abenov R. R., Pokamestov D. A., Rogozhnikov E. V., Demidov Ya. A., Kryukov Ya. V. FBMC/OQAM Equalization Scheme with Linear Interpolation. 2019 Intern. Multi-Conf. on Engineering, Computer and Information Sciences (SIBIRCON). Novosibirsk, Russia, 2019, pp. 0130–0133. doi: 10.1109/SIBIRCON48586.2019.8958090

8. Lele C., Siohan P., Legouable R., Javaudin J.-P. Preamble-based channel estimation techniques for OFDM/OQAM over the powerline. 2007 IEEE Intern. Symp. on Power Line Communications and Its Applications. Pisa, Italy, 26–28 March 2007. IEEE, 2007, pp. 59–64. doi: 10.1109/ISPLC.2007.371098

9. Lele C., Javaudin J.-P., Legouable R., Skrzypczak A., Siohan P. Channel estimation methods for preamble based OFDM/OQAM modulations. European Transactions on Telecommunications. 2008, vol. 19, no. 7, pp. 741–750. doi: 10.1002/ett.1332

10. Kofidis E., Katselis D., Rontogiannis A., Theodoridis S. Preamble-based channel estimation in OFDM/OQAM systems: A review. Signal processing. 2013, vol. 93, no. 7, pp. 2038–2054. doi: 10.1016/j.sigpro.2013.01.013

11. Kalashnikov K. S., Shakhtarin B. I. Synchronization of OFDM Signals in Time and Frequency Domains. Herald of the Bauman Moscow State Technical University. Instrument Engineering. 2011, no. 1, pp. 18–27. (In Russ.)

12. He X., Zhao Z., Zhang H. A pilot-aided channel estimation method for FBMC/OQAM communications system. 2012 International Symposium on Communications and Information Technologies (ISCIT). Gold Coast, Australia, 2–5 Oct. 2012. IEEE, 2012, pp. 175–180. doi: 10.1109/ISCIT.2012.6380885.

13. Abenov R. R., Rogozhnikov E. V., Pokamestov D. A., Kryukov Ya. V., Demidov A. Ya. Channel estimation problems in FBMC systems. Vestnik SibGUTI. 2018, no. 1, pp. 72–78. (In Russ.)

14. Bochechka G. S. Embedded Pilot Channel Estimation Techniques in OFDM Systems // T-Comm – Telecommunica tions and Transport. 2009, no. 3, pp. 38–42. (In Russ.)

15. Farrukh F., Baig S., Mughal M. J. Performance comparison of DFT-OFDM and wavelet-OFDM with zero-forcing equalizer for FIR channel equalization. 2007 International Conf. on Electrical Engineering. Lahore, Pakistan, 11–12 April 2007. IEEE, 2007, pp. 1–5. doi: 10.1109/ICEE.2007.4287350

16. Ding Y., Davidson T. N., Luo Z.-Q., Wong K. M. Minimum BER block precoders for zero-forcing equalization. IEEE Transactions on Signal Processing. 2003, vol. 51, no. 9, pp. 2410–2423. doi: 10.1109/TSP.2003.815387

17. Abenov R. R., Rogozhnikov E. V., Vershinin A. S., Voroshilin E. P. Research of equalization methods for the communication systems using OFDM signals. Vestnik SibGUTI. 2013, no. 1, pp. 50–56.

18. Andrews J. G., Ghosh A., Muyamed R. Fundamentals of WiMax: understanding broadband wireless networking. Westford, USA, Prentice Hall, 2007, 449 p.