在面對快速衰減通道時，單載波區塊傳送系統在設計頻域等化器上，除了需要等化時域上符元間的干擾，還需要處理虛擬載波間的干擾，因此原本應用在非時變通道上的等化器無法直接應用於快速衰減通道。而近來文獻提出改變迭代式區塊決策回授等化器的設計方法，使其能夠應用於快速衰減通道上；與最小均方誤差線性等化器相較，只需增加少量的複雜度，即可大幅提升錯誤率的表現。但此一類等化器只改變回授濾波器之架構，但前饋濾波器仍採用在面對非時變通道時一樣的架構，本論文則考慮時變通道之特性以不同的方法設計前饋濾波器，並探討其效能與複雜度。模擬結果顯示當訊雜比較高時，本論文所提之設計和文獻中之方法相較，有較佳的錯誤率，但須付出相當高之複雜度。

In the thesis, we consider the problem of designing the frequency-domain iterative block decision feedback equalizer (IBDFE) in 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 the virtual inter-carrier interference (virtual ICI) in the frequency domain. Since the conventional IBDFE was originally designed for slow fading channels in which no virtual ICI exists, it suffers from a considerable performance loss when directly applied in fast fading channels. Recently, the conventional IBDFE was modified for the fast fading channel. Compared to the minimum mean square error linear equalizer (MMSE-LE), it gives a much better detection performance with only a slight increase in complexity. The modified IBDFE in the literature adopts a different feedback filter (FBF) structure, but still uses the same feedforward filter (FFF) structure as the conventional IBDFE. Consequently, the virtual ICI is handled by the FBF, but not by the FFF. In this thesis, we consider a variation of the modified IBDFE by adopting a different FFF so that the FFF is capable of suppressing the virtual ICI. We study the performance-complexity tradeoff of the proposed IBDFE structure. Simulation results indicate that, in moderate-to-high signal-to-noise ratio (SNR) situations, the proposed IBDFE gives an improved detection performance over the existing IBDFEs in the literature, but at a cost of a much higher complexity.

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