在單載波頻域等化器通訊系統中，在傳送端與接收端有較高的相
對移動速度情況下，多路徑通道會随著每一個取樣點而改變，於是會降低子載波間的正交性，在接收端的等化器會因子載波間干擾造成效能降低。為了消除子載波間干擾效應，在本篇論文中我們提出了一個可以利用決策訊號回授疊代系統，搭配決策迴授子載波間干擾消除等化器來消除子載波間的干擾。又由於估計出越精確的通道脈衝響應能使決策迴授子載波間干擾消除等化器達到越好的效果，所以我們使用了延展型卡爾曼濾波器與非察覺型卡爾曼濾波器來追蹤通道脈衝響應。最後的模擬結果顯示我們提出的方法在行動單載波頻域等化器通訊系統中能有效的消除子載波間干擾的效應。

In a single-carrier frequency domain equalizer (SC-FDE) system, the time-varying multipath channel can destroy the orthogonality among the subcarriers as the transmitter and the receiver have high relative speed. The intercarrier interference (ICI) phenomenon leads to severe performance degradation. To eliminate the effect of ICI, we propose an iterative decision feedback ICI cancellation equalizer (DFIC) in combination with a decision feedback channel estimation scheme. Since the accurate estimate of the channel impulse response (CIR) can achieve better performance of the DFIC, we consider the extended Kalman filter and the unscented Kalman Filter to estimate the CIR from the nonlinear channel model. Simulation results show that the proposed algorithm can effectively reduce the ICI effect and improve the performance of the SC-FDE system in a time-varying channel.

[1] H. Myung, J. Lim, and D. Goodman, "Peak-to-average power ratio
of single carrier FDMA signals with pulse shaping,"in Proc.
PIMRC, Sep. 2006, pp. 1-5.
[2] M. Rana, M. Islam, and A. Kouzani, "Peak to average power
ratio analysis for LTE systems,"in Communication Software and
Networks, 2010. ICCSN ''10. Second International Conference on,
2010, pp. 516-520.
[3] H. G. Myung, J. Lim, and D. J. Goodman, "Single carrier FDMA
for uplink wireless transmission,"IEEE Veh. Technol. Mag., vol. 1,
no. 3, pp. 30-38, Sep. 2006.
[4] 3rd Generation Partnership Project (3GPP); Technical Specification
Group Radio Access Network; Physical Layer Aspects for Evolved
UTRA,http://www.3gpp.org/ftp/Specs/html-info/25814.htm.
[5] IEEE Standard for Local and Metropolitan Area Networks, Part 16:
Air Interface for Fixed and Mobile Broadband Wireless Access Systems,
IEEE Std. 802.16e-2005, Feb. 2006.
[6] F. Pancaldi, G. Vitetta, R. Kalbasi, N. Al-Dhahir, M. Uysal, and
H. Mheidat, "Single-carrier frequency domain equalization,"IEEE
Signal Process. Mag., vol. 25, no. 5, pp. 37-56, Sep. 2008.
[7] Advanced Television Systems Committee,ATSC Digital Television
Standard,Document A/53,Sept. 16,1995.
[8] Framing Structure, Channel Coding and Modulation for Digital
Television Terrestrial Broadcasting System (in Chinese),Chinese
National Standard GB 20600-2006.
[9] W. Zhang, Y. Guan, W. Liang, D. He, F. Ju, and J. Sun, "An introduction
of the chinese DTTB standard and analysis of the PN595
working modes,"IEEE Trans. Broadcasting, vol. 53, no. 1, pp.
8-13, Mar. 2007.
[10] S. Ohno, "Performance of single-carrier block transmissions over
multipath fading channels with linear equalization,"IEEE Trans.
Signal Process., vol. 54, no. 10, pp. 3678-3687, Oct. 2006.
[11] M. Clark, "Adaptive frequency-domain equalization and diversity
combining for broadband wireless communications,"IEEE J. Select.
Areas Commun., vol. 16, no. 8, pp. 1385-1395, Oct. 1998.
[12] A. Czylwik, "Comparison between adaptive OFDM and single carrier
modulation with frequency domain equalization,"in Proc. Vehicular
Technology Conf., vol. 2, May 1997, pp. 865-869.
[13] M. Huemer, L. Reindl, A. Springer, and R. Weigel, "Frequency
domain equalization of linear polyphase channels,"in Proc. Vehic.
Tech. Conf. (VTC), vol. 3, May 2000, pp. 1698-1702.
[14] N. Benvenuto and S. Tomasin, "On the comparison between OFDM
and single carrier modulation with a DFE using a frequency-domain
feedforward filter,"IEEE Trans. Commun., vol. 50, no. 6, pp.
947-955, June 2002.
[15] D. Falconer, S. Ariyavisitakul, A. Benyamin-Seeyar, and B. Eidson,
"Frequency domain equalization for single-carrier broadband wireless
systems,"IEEE Commun. Mag., vol. 40, no. 4, pp. 58-66, Apr.
2002.
[16] B. Liu, L. Gui, W. Zhang, and J. Xiong, "Frequency domain feedforward
filter combined DFE structure in single carrier systems over
time-varying channels,"IEEE Trans. Consum. Electron., vol. 54,
no. 4, pp. 1569-1575, Nov. 2008.
[17] L.-N. Tran, E.-K. Hong, and H. Liu, "A frequency domain equalization
algorithm for fast time-varying fading channels,"KICS Communications
and Networks, vol. 11, no. 5, pp. 474-480, Oct. 2009.
[18] J.-H. Jang, H.-C. Won, and G.-H. Im, "Cyclic prefixed single carrier
transmission with SFBC over mobile wireless channels,"IEEE
Signal Processing Lett., vol. 13, no. 5, pp. 261-264, May 2006.
[19] J. L. J. Cimini, "Analysis and simulation of a digital mobile channel
using orthogonal frequency-division multiplexing,"IEEE Trans.
Commun., vol. 33, no. 7, pp. 665-675, Jul. 1985.
[20] M. Russell and G. Stuber, "Interchannel interference analysis of
OFDM in a mobile environment,"in Proc. VTC’95, vol. 2, July
1995, pp. 820-824.
[21] J. G. Proakis, Digital Communication. 3rd ed. New York:
McGraw-Hill, 1995.
[22] X. Huang and H.-C. Wu, "Robust and efficient intercarrier interference
mitigation for OFDM systems in time-varying fading channels,"
IEEE Trans. Veh. Technol., vol. 56, no. 5, pp. 2517-2528, Sep.
2007.
[23] W.-S. Hou and B.-S. Chen, "ICI cancellation for OFDM communication
systems in time-varying multipath fading channels,"IEEE
Trans.Wireless Commun., vol. 4, no. 5, pp. 2100-2110, Sep. 2005.
[24] S.-K. Wang and D.-C. Chang, "Pilot-aided channel estimation
methods for ICI reduction in mobile OFDM systems,"in Proc.
of IEEE Consumer Communications and Networking Conference
(CCNC 2009), Jan. 2009, pp. 1-5.
[25] S. Haykin, Adaptive Filter Theory. 4thed. Prentice-Hall, 2001.
[26] Z. Yuanjin, "A novel channel estimation and tracking method for
wireless OFDM systems based on pilots and kalman filtering,"IEEE
Trans. Consum. Electron., vol. 49, no. 2, pp. 275-283, May 2003.
[27] S. J. Julier and J. K. Uhlmann, A new extension of the Kalman filter
to nonlinear systems, 1997, vol. 3068.
[28] C. W. Huang, Iterative Decision Feedback ICI Cancellation Method
for Mobile OFDM Communications. Master Thesis, Department of
Communication Engineering, National Central University, Jhongli
Taiwan,July, 2009.
[29] M. Failli, "Digital land mobile radio communications COST
207,"European Commission, Tech. Rep., 1989.
[30] Y. Li and X. Huang, "The simulation of independent rayleigh
faders,"IEEE Trans. Commun., vol. 50, no. 9, pp. 1503-1514, Sep.
2002.
[31] G. Huang, A. Nix, and S. Armour, "Decision feedback equalization
in SC-FDMA,"in 2008 19th International Symposium on Personal,
Indoor and Mobile Radio Communications, Sep. 2008, pp.
1-5.