近年來，正交分頻多工系統逐漸成為現代通訊系統的主流技術，但它存在著一個最大的問題就是高峰均值比，而頻域等化之單載波區塊傳輸系統完美的克服了這個問題並成為長期演進技術中的實體層上行傳輸技術，然而使用一般的線性最小均方誤差等化器並不能獲得最佳概似解，使用最大似然偵測法雖然能得到最佳解但又會因為過高的複雜度而難以硬體實現。
在本論文中，我們在考量複雜度的情況下試著使用兩種方法來在頻域等化之單載波系統中獲得更低的位元錯誤率。首先，我們使用了基於最小均方誤差之最佳順序連續干擾消除演算法於系統中獲得了更好的系統效能，但其複雜度仍然偏高。其次，我們利用差分度量結合梯度搜尋建立一套有效的偵測演算法，但由於高階數的梯度搜尋仍然會帶來過高的複雜度，我們加入跳躍初始序列的機制，使用數次低複雜度的低階梯度搜尋取代了單次高階梯度搜尋，最後經過模擬的驗證比較後，我們在控制複雜度於可接受範圍內的情況下，提出一個單載波區塊傳輸系統之有效偵測器。

In recent years, orthogonal frequency-division multiplexing (OFDM) systems have gradually become the mainstream technology of modern communication systems. However, it suffers the problem of high peak-to-average power ratio (PAPR). The single-carrier block transmission system with frequency-domain equalization (SC-FDE) can overcome this problem and has been adopted in the long-term evolution (LTE) as an uplink technology. Nevertheless, a general minimum mean square error equalizer (MMSE) cannot obtain the optimum solution. Although using the maximum likelihood (ML) detection can obtain the best solution, its complexity of search is too high to be implemented.
In this thesis, we try to use two methods to improve the bit error rate performance in the SC-FDE system while maintaining the low complexity. First, we apply the optimum order successive interference cancellation based on minimum mean square error (MMSE-OSIC) to the SC-FDE systems. However, its complexity is still too high. Secondly, we introduce the differential metrics and gradient search, and use them in the SC-FDE system. However, the complexity of high-order gradient search is still too high. As a result, we added the scheme with jumping initial sequences, which uses multiple low-level gradient searches instead of a single high-level search. After comparing the simulation results, we finally propose an efficient detection algorithm for the SC-FDE systems with the acceptable complexity.

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