THE DETECTION OF OFDM SIGNALS IN SYNCHRONIZATION SYSTEMS

L. E. Nazarov ¹, A. S. Zudilin ²

¹ Kotel’nikov Institute of Radio-Engineering and Electronics of RAS, Fryazino

² JSC Academician M.F.Reshetnev “Information Satellite Systems”, Zheleznogorsk

The paper is received on September 9, 2016

Abstract. Orthogonal frequency division multiplexing (OFDM) is popular technique in broadband wireless communications due to its advantage to combat channel multi-path and to provide high spectral efficiency. The drawback of OFDM systems is its high sensitivity to synchronization non idealities between the transmitter and receiver oscillators. Specifically incorrect timing synchronization can cause interference between successive symbols and can lead to a severe performance degradation. In addition, a carrier-frequency offset induces an amplitude reduction of the useful signal and provokes interference between adjacent subcarriers. In this paper the problem synchronization in OFDM systems (the detection, symbol timing and carrier-frequency evaluation) is examined and new algorithms of OFDM signal-preamble detection are proposed. The base of these algorithms is recursive sliding discrete Fourier transform that is more efficient that usage of Fast Fourier Transform.

Key words: OFDM signals, synchronization, error performance of detection,  FFT, recursive sliding discrete transform.

References

1. Volkov L.N., Nemirovsky M.S., Shinakov U.S. Sistemy sifrovoi radiosviasy. Basovye metody I harakteristiki. Digital communication systems. [Based methods and characteristics]. Moscow, Eko-Trends. 2005. 392 p. (In Russian)

2. Vishnevskii V.M., Lahov A.I., Portnoi S.L., Shahnovich I.V. Shirokopolosnie seti peredachi. [Broadband communication]. Moscow, Techno-Sphere. 2005. 592 p. (In Russian)

3. Schulze H., Luders C. Theory and Applications of OFDM and CDMA. John Wiley & Sons, Ltd. The Atrium, England. 2005. 408 p.

4. Nazarov L.E., Zudilin A.S. Techniques for narrow band noise reduction for OFDM signals. // Izvestija vysshih uchebnyh zavedenij.Elektronika - Russian microelectronics, 2013, ¹6 (104), p. 45-51.

5. Rabiner L., Gold B. Teoria i primenenie tcifrovoi obrabotki signalov. [Theory and application of digital signal processing]. Moscow: Mir. 1978. 848 p. (In Russian)

6. Shinakov Y.S. Interference power arisi in applications with nonlinearcharacteristic of the amplitude and amplitude-phase shift.// Proektirovanie I technologia elektronih sredstv - Design and technology of electronic means, 2012, ¹3, p. 19-24. (In Russian)

7. Shinakov Y.S. Pick-factor of OFDM signals and nonlinear distortion in the wireless access radioequipment. // Tsifrovaya obrabotka signalov – digital signal processing, 2012, ¹4, p.58-65. (In Russian)

8. Shinakov Y.S. Power spectral density of interference caused by nonlinear distortions in devices with amplitude-phase conversion. // Journal of Communications Technology and Electronics, 2013, Vol. 58, No.10, pp. 1024-1034. DOI: 10.1134/S106422691310001X

9. Shinakov Y.S. Two methods of output signal power calculation for devices with amplitude-phase conversion. // Radiotechnika-Radioengineering, 2016, ¹2, pp. 66-71. (In Russian)

10. Klokov S.S., Shinakov Y.S. The methods of decreasing pick-factor in systems with OFDM technolodgy. // Proceedings of conference “Technolodgy of information society”.  Ìoscow, 2016. pp. 131-132. (In Russian)

11. Nazarov L.E., Zudilin A.S. Estimating the power and efficiency of intermodulation interferences under the OFDM-signal-envelope limitation.// Journal of Communications Technology and Electronics, 2015, Vol. 60, No.5, pp. 489-495. DOI: 10.1134/S1064226915050071

12. Nazarov L.E., Zudilin A.S. Techniques for estimating the power of the intermodulation interferences of orthogonal frequency-division multiplexing signals.// Journal of Communications Technology and Electronics, 2014, Vol. 59, No.2, pp. 158-163. DOI: 10.1134/S1064226914020041

13. Nazarov L.E., Zudilin A.C. Evaluation of intermodulation noise power for OFDM signals with envelope limit clipping.// Zhurnal radioelectroniki - Journal of Radio Electronics, 2013, No6 (In Russian). Available at http://jre.cplire.ru/jre/jun13/1/text.pdf.

14. Nazarov L.E., Zudilin A.C. The modulation and decoding algorithms for OFDM-MSK signals/ // Zhurnal radioelectroniki - Journal of Radio Electronics, 2016, No8 (In Russian). Available http://jre.cplire.ru/jre/aug16/1/text.pdf.

15. Mahmoodi S., Saeedi H., Omidi M.J. OFDM-MSK: A Method for Sidelobe Suppression in OFDM Systems. // 20-th Iranian Conference on Electrical Engineering. Tehran. 2012. 15-17 May. P.1474-1477. DOI: 10.1109/IranianCEE.2012.6292591

16. Bakulin M.G., Kreindelin V.B., Shloma A.M., Shumov A.P. Technologia OFDM. [OFDM Technology]. Moscow, Gorachaa linia – Telecom. 2016. 360 p. (In Russian)

17. Van de Beek J.J., Sandell M., Borjesson P.O. ML Estimation of Time and Frequency Offset in OFDM Systems. // IEEE Transactions on Signal Processing. 1997. V.45. N7. P.1800-1805. DOI:10.1109/78.599949.

18. Steendam H., Moeneclaey M. Synchronization sensitivity of multicarrier systems. // European Transactions on Telecommunications. 2004. N15. P.223-234. DOI:10.1002/ett.975.

19. Sklar B. Tcifrovay svyaz: teoreticheckie osnovi i prakticheskoe primenenie. [Digital Communications: Fundamentals and Applications] Moscow, Izdatelskii dom “Vilams”. 2003. 1104 p. (In Russian)

20. Lutz E. Issues in satellite personal communication systems. // Wireless Network. 1998. N4. P.109-124.