非正交多重接取無線網路中的最佳傳輸功率控制與中繼裝置選擇

Abstract

在本篇論文當中，我們根據裝置對裝置的傳輸技術以及非正交多重接取技術，提出了一個新的演算法應用在無線網路中。基於原始的通道容量，網路傳輸速率會被裝置的通道狀況及距離限制。為了改善位於基地台覆蓋範圍邊緣裝置的傳輸速率，我們使用疊加碼的理論來增大傳輸速率和中繼點的協助來增加傳輸距離。根據已知的通道狀況與疊加碼的理論，我們提出的演算法藉由動態選擇中繼點，並使用最佳的能源分配，以達到將網路效能最大化的效果。我們使用論文中制定的問題，並藉由計算微分，推導並證明出有效的式子，以降低原先選擇中繼點和能源分配的複雜度提高的缺點。更進一步，在論文中也顯示，當來源裝置有一根或多根天線的狀況，與其他演算法的比較結果。在數學結果與模擬結果中，顯示了提出的演算法能有效的改善網路效能。

In this thesis, we use superposition coding and the Non-orthogonal multiple access (NOMA) technology to propose a novel algorithm under Deviceto-Device(D2D) communication in unicast scheme. According to the channel capacity, the transmission rate is limited by the channel gain and the distance of the destination user equipment (UE). To improve the transmission rate of the cell-edge UEs, we use superposition coding and relay-assisted D2D communication to increase the transmission rate and the base station coverage. Based on channel state information and superposition coding theory, the proposed algorithm maximize the network throughput by dynamically selecting the relays and optimally allocating power for different UEs. We use the result of the proposed problem formulation to decrease the computational complexity caused by power allocation and relay selection under NOMA system. Furthermore, we consider the cases under the base station equipped with one antennas and multiple antennas. Simulation results show that the proposed algorithm can efficiently improve network throughput.