Upper and Lower Bounds on ICI Power of FrFT-OFDM Systems in Frequency Selective Time Varying Channels
Subject Areas : electrical and computer engineering
Z.
Mokhtari
1
(University of Tehran)
M.
Sabbaghian
2
(University of Tehran)
Abstract :
In this paper, we study the inter carrier interference (ICI) in fractional Fourier transform based orthogonal frequency division multiplexing (FrFT-OFDM) systems. In this analysis, we derive tight upper and lower bounds for ICI power of FrFT-OFDM systems in doubly dispersive channels. These bounds have considerably simpler expressions than the exact ICI formula. Thus, they provide deep and useful insight into the effect of Doppler frequency, symbol duration, channel delay spread, and angle of transform on the ICI power. This analysis confirms that in the special case of flat fast fading channels the FrFT-OFDM and Fourier transform based OFDM (FT-OFDM) systems exhibit analogous performance while in doubly dispersive channels FrFT-OFDM can achieve better performance than single carrier (SC) and FT-OFDM, if the angle of transform is selected accurately.
[1] Y. Zhou, J. Wang, and M. Sawahashi, "Downlink transmission of broadband OFCDM systems - part II: effect of doppler shift," IEEE Trans. Commun., vol. 54, no. 6, pp. 1097-1108, Jun. 2006.
[2] K. A. Hamdi, "Unified error-rate analysis of OFDM over time-varying channels,'' IEEE Trans. Wireless Communications, vol. 10, no. 8, pp. 2692-2702, Aug. 2011.
[3] M. Martone, "A multicarrier system based on the fractional fourier transform for time-frequency-selective channel," IEEE Trans. Commun, vol. 49, no. 6, pp. 1011-1020, Jun. 2001.
[4] N. Benvenuto, R. Dinis, D. Falconer, and S. Tomasin, "Single carrier modulation with nonlinear frequency domain equalization: an idea whose time has come again," Proceedings of the IEEE, vol. 98, pp. 69-96, Jan. 2010.
[5] S. Pei and J. Ding, "Closed-form discrete fractional and affine fourier transforms," IEEE Trans. Signal Processing, vol. 48, no. 5, pp. 1338-1353, May 2000.
[6] A. Serbes and L. D. Ata, "Eigenvectors of the DFT and discrete fractional fourier transform based on the bilinear transform," in Proc. IEEE 18th Signal Processing and Communications Applications Conf., pp. 268-271, 22-24 Apr. 2010.
[7] B. Tianyang, "A fast two-dimension discrete fractional fourier transform algorithm and its application on digital watermarking," in Proc. IEEE 12th. Int. Conf. on Communication Technology, ICCT'10, pp. 120-123, 11-14 Nov. 2010.
[8] J. Zheng and Z. Wang, "ICI analysis for FRFT-OFDM systems to frequency offset in time-frequency selective fading channels,'' IEEE Communications Letters, vol. 14, no. 10, pp. 888-890, Oct. 2010.
[9] L. B. Almeida, "The fractional fourier transform and time, frequency representations,'' IEEE Trans. Signal Processing, vol. 42, no. 11, pp. 3084-3091, Nov. 1994.
[10] S. C. Pei and J. J. Ding, "Closed-form discrete fractional and affine fourier transforms," IEEE Trans. Signal Processing, vol. 48, no. 5, pp. 1338-1353, May 2000.
[11] K. Panta and J. Armstrong, "Analysis of continuous time domain representation of OFDM signals," in Proc. Australasian Telecommunication Networks and Applications Conf., ATNAC'11, 3 pp. 3, 9-11 Nov. 2011.
[12] Y. Li and L. J. Cimini, "Bounds on the interchannel interference of OFDM in time-varying impairments,'' IEEE Trans. Communications, vol. 49, no. 3, pp. 401-404, Mar. 2001.
[13] S. Barbarossa and R. Torti, "Chirped-OFDM for transmission over time-varying channels with linear delay-doppler spreading,'' in Proc. IEEE Int. Conf. on Acoustics, Speech, and Signal Processing, vol. 4, pp. 2377-2380, Salt Lake City, UT, USA, 7-11 May 2001.
[14] T. Erseghe, N. Laurenti, and V. Cellini, "A multicarrier architecture based upon the affine fourier transform," IEEE Trans. on Commun., vol. 53, no. 5, pp. 853-862, May 2005.