基於虛擬市場機制之正交分頻多重存取極微小基地台網路的動態資源分配

Dynamic Resource Allocation for OFDMA Femtocell Networks: A Virtual Market Approach

陳星翰(Sing-Han Chen)

指導教授 ： 侯廷昭

國立中正大學/工學院/通訊工程學系/碩士(2012年)

摘要

在新世代的行動通訊系統中，極微小基地台網路是突破無線頻寬瓶頸的重要創新。但由於極微小基地台需符合大量佈署 (large-scale deployment) 的要求，加上各個小型基地台的服務需求與通道狀況變化快速，一種能夠自行調整 (self-configure) 的資源分配演算法備受研究社群期待。
本研究分析當前固定分配方法之不足，提出一種類似市場運作的機制。本提議架構中，各基地台自行評估下個分配周期的服務能力，並藉此資訊競標無線通道資源。同一時間，對於可能的同頻道干擾 (co-channel interference) ，使用一個收費策略來控制系統內各基地台對其他行動台的不良影響。
這樣的收費機制可以藉由斯塔克爾伯格模型 (Stackelberg model) 分析出每一回合收費價格的均衡點。據此，每個分配周期之間，各基地台得以分散式 (distributively) 的進行傳輸功率的調整。
最終，我們提出的演算法能結合傳統(c,s,n)=(1,3,1)分配與(c,s,n)=(1,3,3)分配的優點。並且無論在細胞內部或細胞邊緣都能在遠低於(c,s,n)=(1,3,3)的阻斷率 (blocking probability) 下提供較高的總系統吞吐量。並且，本演算法能在不同的系統行動台數目下維持效能優勢，進以證明本演算法在不同情況下仍能自我調適、達成強韌性 (robustness) 。

關鍵字

動態資源分配 ； 功率控制 ； 斯塔克爾伯格模型 ； 競標機制 ； 虛擬市場

並列摘要

This thesis studies the issues of resource allocation and power control for femtocell networks. In this network system, to reduce co-channel interference, a self-configuration method with reasonable information overhead is in great need.
We formulate the channel allocation into a market style problem. It means each femto base station (FBS) can be considered as a bidder to bid the channels within a sector of the macro base station (MBS). For each FBS, it will obtain its own “bidding price” by the potential service capability in the next cycle.
To provide higher frequency reuse, we propose an interference constrained allocation scheme. It means we allow the nearby FBSs to have the chance to be allocated the same channel. The interferences are foreseeable. But, with the help of pricing on the power setting of conflicting channels, we can calculate the optimal power with limited interference. The Stackelberg model has been used for our analysis on pricing policy.
In the end, the simulation shows that we achieve higher system throughput than both the traditional (c,s,n)=(1,3,1) and (c,s,n)=(1,3,3) reuse policy with a relatively smaller blocking probability.

並列關鍵字

dynamic resource allocation ； power control ； Stackelberg model ； auction design ； virtual market

參考文獻

[4] X. Kang, R. Zhang, and M. Motani, “Price-Based Resource Allocation for Spectrum-Sharing Femtocell Networks: A Stackelberg Game Approach,” IEEE Journal on Selected Areas in Communications, vol. 30, no. 3, pp. 538 –549, Apr. 2012.

[6] V. Chandrasekhar, J. Andrews, and A. Gatherer, “Femtocell networks: a survey,” IEEE Communications Magazine, vol. 46, no. 9, pp. 59 –67, Sep. 2008.

[7] D. Lopez-Perez, A. Valcarce, G. de la Roche, and J. Zhang, “OFDMA femtocells: A roadmap on interference avoidance,” IEEE Communications Magazine, vol. 47, no. 9, pp. 41 –48, Sep. 2009.

[9] H. Hindi, “A tutorial on convex optimization II: duality and interior point methods,” in American Control Conference, 2006, 2006, p. 11 pp.

[11] M. Felegyhazi and J.-P. Hubaux, “Game Theory in Wireless Networks: A Tutorial,” École Polytechnique Fédérale de Lausanne, Technical Report LCA-REPORT-2006-002, Jun. 2007.