在本篇論文中，我們將研究以單載波空時塊碼的通訊系統，並加入分碼多工系統及低複雜度遞迴式使用者偵測技術，且考慮在具有符元間干擾的傳輸通道中運作，並且為了增加傳送速度，我們採用超級正交空時塊碼的基本架構來作延伸。在傳送端，為了能使超級正交空時塊碼與分碼多工系統、單載波空時塊碼結合，又不失其三者特性，我們提出一種新的空時塊碼的架構，以兩根傳送天線為例，此架構每人需要兩個展頻序列，來作為辨別使用者的方法，並且藉由多重格子碼調變，我們可提升傳送速度，並應用在多使用者上。在接收端我們考慮低複雜度的遞迴式多使用者的接收端，利用”每個使用者使用不同的展頻碼”的系統特性，同時配合以渦輸碼原理設計之解碼器來做解碼，而接收端的架構類似是串聯式的渦輪解碼結構。一個軟式的干擾消除裝置在接收端前段利用已精確得知的通道資訊，同時利用最小均方差之原理提供對編碼位元的可靠估測。而其輸出的附帶資訊(針對已編碼的位元)在解交錯會送入解碼器做解碼。模擬結果將藉由不同的使用者人數與不同的展頻碼長度等變數來進行分析。

In this thesis, we combine single carrier space-time blocked transmission with multi-user CDMA system, in the meanwhile, we adopt low complexity iterative multi-user detection and consider frequency selective fading channel. Besides, in order to increase data rate, we use super-orthogonal codes to extension. In transmitter, for combination of super-orthogonal codes, CDMA system and single carrier transmission, we propose a new space-time block codes structure. Take two transmitter antennas as an example, this structure need to have two spreading sequence to distinguish different user. Utilization of MTCM, we can increase data rate and apply this structure to multi-user system. The receiver, based on these user-specific sequences, intends to differentiate the active users by invoking the “turbo principle” decoding due to the serially concatenated framework. A soft-input soft-output (SISO) interference suppressor for each user is first derived by minimum mean-square error sense to provide the reliability estimates of coded bits, assuming the channel state information is known precisely at the receiver. The resulting extrinsic information for coded bit streams is passed through a bank of single-user decoders after being de-interleaved. Simulation results demonstrate system performance in terms of bit error probability with variant ratio of the number of users to spreading length for the receiver equipped with multi-antennas. Besides, the performance comparison with conventional coded DS-CDMA systems is also manifested under the constraint of identical power and bandwidth efficiencies.

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