在傳統無線網路下對D2D通訊的兩階段最佳化資源分享

Two-Stage Resource Sharing Optimization for D2D Communication Underlying Cellular Networks

林詩翰(Shih-Han Lin)

指導教授 ： 高榮駿

國立清華大學/電機資訊學院/資訊工程學系所/碩士(2017年)

摘要

第五代行動通信系統要求行動網路必須支援較高的同時服務的裝置數量、較高的網路傳輸速率、以及較高的頻譜效率。裝置對裝置(Device-to-Device, D2D)通訊技術也被認為是能夠達成第五代行動通信系統要求的重要技術之一。D2D通訊藉由重覆利用頻譜資源來增加頻譜效益和使用者數量，而重覆利用頻譜的D2D裝置會對其它使用者造成額外的頻道干擾，因此利用適當的頻譜資源分配和功率調配來減少頻道干擾、增加頻譜效益、提高系統吞吐量等是D2D通訊技術的研究重點。本篇論文的研究主題是如何在傳統無線網路下利用裝置對裝置傳輸技術來進行頻譜資源分配。
現今大多數的資源分配方法會使得基地台分配完所有的頻譜資源給D2D使用者。但是現實中的網路環境變化非常快速，使用者頻繁的移動模式會改變網路拓樸。如果基地台已經分配完所有的頻譜資源，一旦有新的使用者加入，基地台就必須重新分配資源和調配功率，所以多變的網路環境會大幅增加基地台的運算負擔。因此，為了讓基地台能夠更彈性的分配資原，本篇探討的議題為如何在滿足所有使用者的傳輸品質需求下，最小化被分配出去的頻譜資源數量。
我們的方法為兩階段的資源分享最佳化。最小化被分配出去的頻譜資源數量是一個NP-Hard的問題，無法再多項式時間內解出，因此我們在第一階段中利用condensation method將這個問題連續近似成一個凸優化問題(Convex optimization)來解出。第二階段則是在第一階段求出的資源分配結果下，為了最大化整體的傳輸速度，利用block successive upper-bound method進行傳輸功率調配。而實驗結果顯示我們的資源分配方法在使用的頻譜資源數量、傳輸速度上都有很好的表現。

關鍵字

頻譜資源分享 ； 功率調配 ； 點對點傳輸

並列摘要

Device-to-Device (D2D) communication is a promising solution to increase the system throughput and spectral efficiency in 5G mobile networks. However, D2D communication may cause serious mutual interference among D2D pairs and cellular users (CUEs) because D2D pairs and CUEs share the same radio resource. In this thesis, we formulate the uplink resource sharing problem and propose the Two-Stage Resource Sharing Optimization (TCBO) algorithm. In order to make base station allocate resource blocks (RB) more flexibly, the primary goal of the proposed algorithm is to minimize the number of resource blocks reused by D2D pairs while satisfying SINR requirements of all user. The secondary goal is to maximize the overall system throughput. Two-stage resource sharing optimization algorithm we propose contains two parts. The primary goal of the resource allocation problem is a NP hard problem, so the first-stage of our algorithm uses the condensation method to formulate the primary goal as a geometric programming (GP) and then solve it with convex optimization methods. Given the results of the first stage, the second-stage of our algorithm exploits the block successive upper-bound method (BSUM) to formulate the secondary goal as a convex optimization problem. Simulation results show that the two-stage resource sharing optimization algorithm not only reduces the number of reused RBs, but also results in high system throughput.

並列關鍵字

D2D ； Resource allocation ； Power control

參考文獻

[1] Chenfei Gao, Xiang Sheng, Jian Tang, Weiyi Zhang, Shihong Zou, and Mohsen Guizani, “Joint Mode Selection, Channel Allocation and Power Assignment for Green Device-to-Device Communications,” IEEE International Conference on Communications (ICC), pp. 178-183, Sydney, Australia, June, 2014.

[2] Feiran Wang, Chen Xu, Lingyang Song, Qun Zhao, Xiaoli Wang, Zhu Han, “Energy-Aware Resource Allocation for Device-to-Device Underlay Communication,” IEEE International Conference on Communications (ICC), pp. 6076-6080, Budapest, Hungary, June, 2013.

[3] Feiran Wang, Chen Xu, Lingyang Song, Zhu Han, Baoxian Zhang, “Energy-Efficient Radio Resource and Power Allocation for Device-to-Device Communication Underlay Cellular Networks,” IEEE Wireless Communications and Signal Processing (WCSP), pp. 1-6, Huangshan, China, October, 2012.

[4] Zhenyu Zhou, Mianxiong Dong, Kaoru Ota, Jun Wu, Takura Sato, “Distributed Interference-Aware Energy-Efficient Resource Allocation for Device-to-Device Communication Underlaying Cellular Network,” IEEE Global Communications Conference (GLOBECOM), pp. 4454-4459, Austin, TX, USA, December, 2014.

[5] D. Feng, L. Lu, Y. Yuan-Wu, G. Li, G. Feng, and S. Li, “Device-to-device communications underlaying cellular networks," IEEE Transaction on Communications, vol. 61, pp. 3541-3551, Aug. 2013.