可攜式多媒體應用和移動通訊已成為我們生活中不可或缺的一部分。眾所周知，使用多個天線來創建多輸入多輸出（MIMO）無線通道可以顯著提高數據速率和可靠性以增強資料的傳輸品質。對於給定數量的發射和接收天線，Zheng和Tse提出在分集和復用增益之間存在連續的線性權衡(Diversity–Multiplexing Gain Tradeoff)，並在高訊號雜訊比的條件下利用合適的空時編碼量化了可實現的最大分集和復用增益。
近年來，空間時間碼被證明了在多根天線下，在多條衰落通道中利用此編碼技術可以提高系統的資料傳輸率和並增加更正錯誤的能力已實現巨大的性能提升。在空時編碼中，利用在發射機處採用多根傳送天線，對傳輸資料符元進行在空間和時間相互交錯的智能編碼，以便於多工增益和分集多樣性從中獲得提升。
在本論文中，我們計算了在頻率非選擇性衰退通道下線性調變之空間時間編碼設計準則的分集復用權衡。此編碼設計準則基於特殊的時間空間碼架構模型，由一個迴旋編碼器及一個空間編碼器所組成。此空間時間碼利用除法代數提供簡單的數學模式來建造線性調變之時間空間碼，以達到分集復用權衡。而在相同的天線條件下，相較於一般的空時碼，迴旋編碼器將提供更高的多重性增益，以確保更可靠的傳輸品質。而解碼器是利用維特比解碼器，用於執行最大似然順序解碼。最後在相同頻寬效率下不同時間空間編碼做模擬圖之比較與驗證理論推導的正確性。

In this thesis, we derived a simple diversity-multiplexing tradeoff of a space-time coding scheme for linear modulation over frequency-nonselective fading channels. With an optimal convolutional temporal encoder and the Golden spatial code, which achieves the full transmit spatial diversity, the maximum overall diversity gain is Lr*Lt*ECL over fast fading channels, where Lr is the number of receive antennas, Lt the number of transmit antennas, ECL the effective code length of the convolutional encoder. With the Viterbi decoder, simulation results demonstrate the theoretical analysis and justify the effectiveness of our coding scheme.

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