應用於合作無線隨意網路中利用增加空間性頻道使用來增進效能之中繼點選擇機制

Abstract

在近幾年內，學者們提出了一類稱為合作通訊的方法，這類方法能使配備單一天線的行動裝置在多使用者的環境中分享彼此的天線以建立一個虛擬化的多天線傳送端。由於花費或是硬體上的限制，行動裝置可能沒辦法配備多天線。但透過合作通訊，一個配備單一天線的行動裝置也能在多使用者的環境中以虛擬化的多天線傳送端達到發射分送的效果。 在這篇論文中，我們提出了一種中繼點選擇機制，針對中繼點附近傳輸的多寡等情形挑選出一個被影響較少也影響其他傳輸較少的中繼點，而這個方法是為了要達到空間性頻道重複使用最大化的目的。透過使用ns-2網路模擬器，我們評估了使用這個方法的效能。實驗結果顯示，即使是受到鄰近傳輸的影響，較為穩定增加的網路吞吐量以及所維持之降低的網路延遲時間表現出了使用這個方法的優越之處。

In the last few years, a new class of methods called cooperative communication has been proposed that enables single-antenna mobiles in a multi-user environment to share their antennas and generate a virtual multiple-antenna transmitter. A mobile station may not be able to support multiple transmit antennas due to some hardware limitations. Through cooperative communication, a single-antenna mobiles in a multi-user environment can utilize the virtual multiple-antenna transmitter to achieve the transmit diversity. In this thesis, we propose a relay selection scheme which considers neighbor traffic of the relay node in order to maximize the spatial channel reuse in the cooperative communication. Through the simulation with ns-2 simulator, we evaluated the performance of the proposed scheme. As presented by the simulation results, the more stable increase in the total network throughput and the reduction in delay even when affected by neighbor traffics show the outperformance by utilizing the proposed scheme.