毫微蜂巢式基地台下干擾抑制之資源分配演算法

Abstract

密集的毫微蜂巢式基地台布建會對彼此造成強烈的干擾，使得使用者無法傳輸資料的機率上升。利用資源分配的方式可以有效的降低發生無法傳輸資料的機率，但是在正交分頻多工存取的傳輸技術下，卻無法用最佳化的方式找到最佳解。本論文提出一種應用正交分頻方式的資源分配方法，利用正交分頻的概念去避開基地台彼此之間的干擾，同時儘量增加不會造成干擾的通道使用個數來提升整個系統的傳輸量。因為正交分頻的資源分配方法需要毫微蜂巢式基地台的合作，所 以在所提出的方法內定義了一個資源交換規則。從模擬結果可以看出本論文提出的資源分配方法在系統傳輸量、使用者無法傳輸資料的機率、資源分配的公平性以及省能源的能力上都有很明顯的效能提升。

Femtocells have strong inter-cell interference causing high user outage rate under a dense deployment model. Resource allocation is an effective method to save outage users and improve system throughput. Under OFDMA system, the optimal solution of resource allocation is a NP-hard problem. In this thesis, a simple orthogonal subchannel allocation method is proposed. The concept of the method is to utilize the benefit of orthogonal subchannel selection for interference mitigation and explore the co-channel transmission opportunity to increase the system throughput. Because the orthogonal subchannel selection requires cooperation of femtocells, a trading rule is included in proposed method for regulating requests of femtocells. The simulation results show significant improvements on system throughput, user outage rate, fairness and power saving brought by proposed method.