重疊網路下毫微微型與巨型蜂巢系統之資源配置

當毫微微型基地台(Femto base station)被重疊部屬於巨型基地台(Macro base station)的區域時，因為毫微微型基地台可以重複使用巨型基地台的頻段，以及部屬在巨型基地台信號被遮蔽之處，所以毫微微型基地台可有效改善重疊網路的整體吞吐量以及增加巨型基地台的覆蓋度。但是管理重複使用相同資源所造成的同階層干擾(co-tier interference)及跨階層干擾(cross-tier interference)，就成為一個重要的問題了! 本篇論文所提出的方法為基於圖論(Graph theory) 的一種中央化的(centralized)演算法，所建構出的加權干擾圖 (weighted interference graph)中，頂點為各個毫微微型基地台，彼此連線的權重則是兩基地台間的干擾。首先先把頻段分為兩種，第一種為尚無任何巨型基地台使用裝置(MUEs)使用的頻段，第二種則為已被巨型基地台使用裝置使用的頻段。而本篇論文將分為三段來討論此問題，第一段主要討論第一種頻段，將使用分群的方法將同階層干擾較嚴重的毫微微型基地台分開成不同群，如此同一群的基地台就可以重複使用相同資源。第二段則主要探討當使用共享式頻譜(shared spectrum)，毫微微型基地台要如何分配資源，以減輕同階層干擾及跨階層干擾的問題。而最後第三段的問題則主要著重於當巨型基地台使用裝置(MUEs)的數量有所增減時，如何根據前兩段的結果，提出根據使用者變化模式改變的簡單重新分配方法。

關鍵字

毫微微型基地台；資源分配；干擾管理；干擾圖；同層干擾；跨層干擾

並列摘要

In femtocell and macrocell underlaying network, thank to spetrum reusage of Marcro base station, femto base stations can increase throughput and coverage of the cellular network effectively. However, cross-tier interference and co-tier interference come with the spectrum reusage and remain as a serious challenge to be dealt with. In this thesis, we propose a centralized algorithm based on the graph theory. The algorithm constructs a weighted interference graph based on interference amount among femto base station, and the number of served users by each femto base station. The available spectrums for femto base stations are divided into two categories: Macro User Equipments (MUEs)-free subchannels and MUEs-occupied subchannels. In the first part of the thesis, we will discuss how to allocate the MUEs-free subchannels. According to the weighted interference graph, femtocells are grouped in order to minimize the co-tier interference by the proposed clustering algorithm. In the second part, we dicuss how to reuse MUEs-occupied subchannels and minimize co-tier and cross-tier interference at the same time by extending the clustering algorithm proposed in chapter 2. Finally, a dynamic resource sharing scheme is amended considering MUEs' mobility. A markovian state machine is introduced to model the entering and leaving behaviors of MUEs. Consequently, this state machine is merged into the proposed clustering scheme and a dynamic clustering algorithm is achieved.

並列關鍵字

femtocell ； resource allocation ； interference management ； interference graph ； cross-tier interference ； co-tier interference

參考文獻

[1] F. J. Mullany, L. T. W. Ho, L. G Samuel, and H. Claussen, “Self-deployment,self-configuration: Critical future paradigms for wireless access networks,” in Lecture Notes on Computer Science LNCS, vol. 3457, pp. 58–68.

[2] S. Sharma, A. R. Nix, and S. Olafsson, Situation-aware wireless networks, IEEE

Communications Magazine, vol. 41, No. 7, pp. 44–50, 2003.

future mobile communication ,” Electronics & Communication Engineering

Journal, vol. 12, No. 3, pp. 133–147, 2000.

國際替代計量

重疊網路下毫微微型與巨型蜂巢系統之資源配置

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