快速衰減通道中，在單載波區塊傳送系統下，文獻中提出了迭代式區域決策回授等化器，作為頻域等化器，並從非時變通道延伸到時變通道。迭代式區域決策回授等化器不僅可以解決時域上符碼間的干擾，在頻域上同時可以抑制虛擬載波的影響。本論文中，利用最小均方誤差的準則去設計時變通道下的頻域決策回授等化器，並且為了決定等化器參數，估計了傳送訊號與決策訊號之間的相關性，並討論不同的估計相關性方法。對比於其他文獻，本論文簡化了頻域決策回授等化器的前饋濾波器係數，因此降低了複雜度，並採用了新的估計相關性方法，模擬結果顯示，與文獻作對比，在減少複雜度下，獲得了不錯的錯誤率表現。

In the literature, we consider the problem of designing the frequency-domain iterative block decision feedback equalizer (IBDFE) from slow fading channels to fast fading channels for the single-carrier block transmission (SCBT) system. In this situation, the IBDFE needs to deal with not only the inter-symbol interference (ISI) in the time domain, but also suppress the virtual inter-carrier interference (virtual ICI) in the frequency domain. In the thesis, IBDFE was designed for doubly selective channels according to the MMSE criterion, In order to decide equalizer coefficient, we require the knowledge of the correlation between the detected symbols and the transmitted symbols, methods of estimating the correlation are also discussed in the thesis. Compared to other literature, we simplify feedforward filter coefficient and propose new method to estimate correlation. Simulation results indicate that, the new method which reduce complexity of IBDFE also have good performance.

[1] Kuei-Chiang Lai, Chin-Chi Yang, and Chi-Jen Chen, “Frequency-Domain Iterative Block DFE for Single-Carrier Systems in Doubly-Selective Channels”
[2] 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, Jun. 2002.
[3] N. Benvenuto and S. Tomasin, “Iterative design and detection of a DFE in the frequency domain,” IEEE Trans. Commun., vol. 53, no. 11, pp. 1867-1875, Nov. 2005.
[4] W. G. Jeon, K. H. Chang, and Y. S. Cho, “An equalization technique for orthogonal frequency-division multiplexing systems in time-variant multipath channels,” IEEE Trans. Commun., vol. 47, pp. 27-32, Apr. 1999.
[5] Y.-S. Choi, P. J. Voltz, and F. A. Cassara, “On channel estimation and data detection for multicarrier signals in fast and selective Rayleigh fading channels,” IEEE Trans. Commun., vol. 49, pp. 1375-1387, Aug. 2001.
[6] C. Zhang, Z. Wang, Z. Yang, J. Wang and J. Song, “Frequency domain decision feedback equalization for uplink SC-FDMA,” IEEE Trans. Broadcasting, vol. 56, no. 2, pp. 253-257, Jun. 2010.
[7] J. Y. Pan, “Signal detection of single-carrier block transmission using frequency domain decision feedback equalizer,” Institute of Computer and Communication Engineering National Cheng Kung University Thesis for Master of Science, July 2011.
[8] Fumiyuki Adachi, Hiromichi Tomeba, and Kazuki Takeda, “Introduction of frequency-domain signal processing to broadband single-carrier transmissions in a wireless channel,” IEICE Trans. Commun., vol.E92-B, no.9 september 2009.
[9] B. O'Hara and A. Petrick, IEEE 802.11 Handbook: A Designer's Companion, Standards Information Network IEEE Press, Dec. 1999.
[10] Chin-Chi Yang, “Iterative frequency-domain equalizer in fast fading channels for signal-carrier block transmission,” Institute of Computer and Communication Engineering National Cheng Kung University Thesis for Master of Science, July 2014.
[11] Yi-Chung Huang, “The Design of Frequency-Domain Iterative Block Decision Feedback Equalizer in Fast Fading Channels for Single-Carrier Block Transmission Systems,” Institute of Computer and Communication Engineering National Cheng Kung University Thesis for Master of Science, July 2016.