在本篇論文中，我們首先專注於相差MPSK在兩階段雙向中繼網路架構的解碼轉發。針對中繼節點的最大可能性(maximum-likelihood)檢測器，我們提出了兩個終端的發送信號的距離測量。基於所提出的距離，我們解釋其用戶不能使用相同星座圖的原因，並找到了使用決策反饋與沒使用決策回饋的最佳星座圖角度。接著，我們將此中繼點的非同調二用戶偵測，推廣為非同調三用戶偵測。我們將這些結果應用在非正交多存取，並且以電腦模擬比較其與正交多存取的錯誤率。 ;Wireless communications is required to transmit quantity of data more and more. An important studying topic is how to transmit the same quantity of data in a shorter period of time. Recently, two-way relaying is a popular subject, where two terminal nodes transmit to each other with the help of the relay node. Two-phase two-way relaying (TPTWR) using physical-layer coding is a bandwidth efficient technique. Several TPTWR schemes using differential phase-shift keying (DPSK) which avoid the rate loss due to pilot symbols were proposed.
In this thesis ,we first focus on differential MPSK for TPTWR using decode and forward technique. We propose that the signal constellation of one terminal is the signal constellation of the other terminal rotated by an angle. For the noncoherent maximum-likelihood detector at the relay, we propose a distance measure for the transmitted signals of the two terminals. Based on the proposed distance, we find the optimal angles for both cases of using decision feedback or not. Then the noncoherent two-user detection at the relay is extended as noncoherent three-user detection. We apply these results to NOMA(non-orthogonal multiple access), and compare it with OMA(orthogonal multiple access) by computer simulation.
