在全雙工多細胞的系統下減少干擾的新設計

Abstract

全雙工通訊允許兩個以上的使用者在同一個頻帶上做傳輸。這樣的系統有機會將通道容量提升為半雙工的兩倍。然而在全雙工的系統下，使用者因為共享同一個頻帶，彼此間會產生很強的干擾，而這些干擾將會限制通道容量。因此在全雙工的系統下，減少干擾是目前最重要的問題。在這篇論文裡，我們聚焦在全雙工多細胞系統下資源的分配。不僅是細胞內的干擾，細胞間的干擾也在我們考慮的範疇中。基於蟻群最佳化的概念，我們提出一個演算法專門來解全雙工多細胞系統下資源分配的問題。就我們所知，目前沒有任何研究是用蟻群最佳化來解全雙工多細胞系統下資源分配的問題。模擬的結果顯示我們的方法勝過貪婪式搜尋法。雖然我們的演算法無法找到最佳解，但是相較於能找到最佳解的地毯式搜尋法，我們提出的演算法的複雜度並不像它那麼高。

Full-duplex (FD) communications enable more than one users to transmit and receive signals on a single channel. This kind of system has potential to double the capacity of a half-duplex (HD) system. However, because the users of full-duplex share the same frequency, they suffer from severe interference. The increased interference limits the capacity for improvement. Therefore, the greatest problem to solve in full-duplex system is to mitigate interference from others. In this thesis, we focus on resource allocation in a full-duplex multi-cell system in which there is not only intra-cell interference but also inter-cell interference. We proposed an algorithm based on Ant Colony Optimization to find an acceptable good solution of the resource allocation problem between cells. To the best of our knowledge, there is no research using an idea of ant colony to solve the resource allocation problem in full-duplex multi-cell systems. Simulation results show that our method provides better performance than centralized greedy search method. Compared to exhaustive search, which is always the best one if only taking system performance into consideration, the complexity of our method is not as high as that of exhaustive search, even though our method needs a great number of iterations.