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Be Cautious When Analyzing the Sampling Clock Offset in OFDM Systems

Abstract

Many studies have analyzed the effects of sampling clock offset (SCO) on orthogonal frequency-division multiplexing (OFDM) systems. The results of these studies are based on one of two discrete representations of continuous time-domain OFDM signals: (1) a subcarrier set consisting of both negative and positive frequencies, or (2) a subcarrier set comprising only positive frequencies. This paper discusses whether there is any difference between the two representations in the presence of SCO. When SCO is not considered, both representations are equivalent because of aliasing. In the presence of SCO, we derive a closed form of signal-to-interference-plus-noise ratio (SINR) expressions for both cases and compare their performances in terms of SINR by numerical analysis. The latter representation shows worse SINR performance compared to the former representation because the effect of SCO is more relevant for high frequencies and the latter representation has complex exponentials with high frequencies. Therefore, for fair comparisons of performance, caution is needed when analyzing SCO in OFDM systems.

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References

  1. 1.

    Speth, M., Fechtel, S. A., Fock, G., & Meyr, H. (1999). Optimum receiver design for wireless broad-band systems using OFDM—Part I. IEEE Transactions on Communications, 47(1), 1668–1677.

  2. 2.

    Hwang, T., Yang, C., Wu, G., Li, S., & Li, Y. (2009). OFDM and its wireless applications: A survey. IEEE Transactions on Vehicular Technology, 58(4), 1673–1694.

  3. 3.

    Santella, G. (2000). A frequency and symbol synchronization system for OFDM signals: Architecture and simulation results. IEEE Transactions on Vehicular Technology, 49(1), 254–275.

  4. 4.

    Wang, X., Tjhung, T. T., Wu, Y., & Caron, B. (2003). SER performance evaluation and optimization of OFDM system with residual frequency and timing offsets from imperfect synchronization. IEEE Transactions on Broadcasting, 49(2), 170–177.

  5. 5.

    Roman, T., Visuri, S., & Koivunen, V. (2006). Blind frequency synchronization in OFDM via diagonality criterion. IEEE Transactions on Signal Processing, 54(8), 3125–3135.

  6. 6.

    Lin, D. D., Pacheco, R. A., Lim, T. J., & Hatzinakos, D. (2006). Joint estimation of channel response, frequency offset, and phase noise in OFDM. IEEE Transactions on Signal Processing, 54(9), 3542–3554.

  7. 7.

    Kim, Y.-H., & Lee, J.-H. (2011). Joint maximum likelihood estimation of carrier and sampling frequency offsets for OFDM systems. IEEE Transactions on Broadcasting, 57(2), 277–283.

  8. 8.

    Sliskovic, M. (2001). Carrier and sampling frequency offset estimation and correction in multicarrier systems. IEEE Global Telecommunications Conference (GLOBECOM), 1, 285–289.

  9. 9.

    Laourine, A., Stephenne, A., & Affes, S. (2006). Blind sampling clock offset estimation in OFDM systems based on second order statistics. In The 40th Asilomar conference on signals, systems and computers (ACSSC) (pp. 1782–1785).

  10. 10.

    Aghajeri, S., Gholami M. R., & Nikopoor, H. (2007). Blind sampling clock adjustment in OFDM power line communication. In The 9th international symposium on signal processing and its applications (ISSPA) (pp. 1–4).

  11. 11.

    Gault, S., Hachem, W., & Ciblat, P. (2006). Joint sampling clock offset and channel estimation for OFDM signals: Cramér-Rao bound and algorithms. IEEE Transactions on Signal Processing, 54(5), 1875–1885.

  12. 12.

    Proakis, J. G. (2001). Digital communications. New York: McGraw-Hill.

  13. 13.

    Razavi, B. (1998). RF microelectronics. Upper Saddle River, NJ: Prentice Hall.

  14. 14.

    Kim, Y.-H., & Lee, J.-H. (2011). Comparison of passband and baseband transmission schemes for power-line communication OFDM systems. IEEE Transactions on Power Delivery, 26(4), 2466–2475.

  15. 15.

    Wu, S., & Bar-Ness, Y. (2004). OFDM systems in the presence of phase noise: Consequences and solutions. IEEE Transactions on Communications, 52(11), 1988–1996.

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Acknowledgments

This work was supported in part by the ICT R&D program of MSIP/IITP [B0101-15-1347], and in part by the Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Science, ICT & Future Planning [NRF-2014R1A1A1A05005551], Republic of Korea.

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Correspondence to Yong-Hwa Kim.

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Sung, Y., Kim, Y., Lee, J. et al. Be Cautious When Analyzing the Sampling Clock Offset in OFDM Systems. Wireless Pers Commun 85, 1701–1711 (2015). https://doi.org/10.1007/s11277-015-2819-y

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Keywords

  • Sampling clock offset (SCO)
  • Orthogonal frequency-division multiplexing (OFDM)
  • Signal-to-interference-plus-noise ratio (SINR)