無線通訊所需傳送的資料量越來越多，所以如何在越短時間內傳送相同資料量是重要的研究主題。兩終端節點藉由中繼節點同時傳送訊號至彼此的雙向無線通訊技術為近年來熱門的研究，而實體層網路編碼可以進一步提升頻寬效益。另一方面，相差編碼不需要傳送前導符元做通道估測，故不會造成速率損失，也是一個值得研究的通訊技術。

在本篇論文中，我們研究使用單一中繼節點的放大轉發和解碼轉發之相差編碼兩階段雙向無線傳輸架構，首先將一些既有論文在相同條件下比較。我們使用多位元相位偏移調變，將其在不同的通道模型下做模擬，且本論文也研究三階段雙向無線傳輸架構，並基於相同傳輸速率做比較。

除此之外，本論文提出了一個新的使用M-PSK訊號之解碼轉發架構，我們利用中繼節點在前兩個時間收到的訊號去估計參考訊號，再將估計的參考訊號用於目前訊號的判斷。由模擬結果顯示，我們提出的新架構有最好的錯誤效能。

Wireless communications is required to transmit quantity of data more and more. The important studying topic is how to transmit the same quantity of data in a shorter period of time. Recently, two-way wireless communication is a popular type of communication technology, where two terminal nodes transmit simultaneously to each other with the help of the relay node. The physical layer network coding can further improve bandwidth efficiency. On the other hand, differential encoding is not required to transmit pilot symbols for channel estimation, so it does not cause rate loss. It is also a communication technology worth studying.

In this thesis, we study differential encoding for two-phase two-way wireless transmission with the single-relay for amplify-and-forward (AF) and decode-and-forward (DF). First, we compare existent techniques under the same conditions. We use M-PSK (phase-shift keying) modulation, and do computer simulations under different channel models. We also study three-phase two-way wireless transmission, and compared two-phase transmission with three-phase transmission based on the same transmission rate.

Besides, in this thesis, we propose a new decode-and-forward scheme using M-PSK signals. This scheme uses the received signals at the relay in previous two time slots to estimate the reference signal, and then decide the current signal according to the estimated reference signal. Simulation results show that the proposed scheme has the best error performance.

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