D2D通訊為兩個行動設備間的通訊無須通過基地台，其可提升頻譜效率、系統容量及蜂窩覆蓋率。當D2D通訊與蜂窩網路共享頻段時，此稱為重疊式帶內D2D (underlay inband D2D)，重疊式帶內D2D由於與蜂窩網路共用頻段，D2D通訊與蜂窩設備和基地台間通訊會互相干擾，故先前研究主要使用資源分配來決定哪些D2D與蜂窩設備配對來共用頻段以降低干擾問題，這些研究大多以一最小距離為門檻值，當D2D與蜂窩設備距離超過此門檻值即可共用頻段，然超過此門檻值僅表示D2D與蜂窩設備間互相干擾較小，但不代表可得到理想的頻寬，因此本論文提出多重虛擬扇區之資源分配方法(Resource Allocation with Multiple Virtual Sectors，MVS)，試圖在超過此門檻值的條件，進一步將D2D與干擾程度較低的蜂窩設備作配對，以降低干擾來提升整體產能(Throughput)，MVS具有三項特點：(1)扇區切割：將整個區域以基地台為圓心，依不同的半徑及角度切割成若干個扇區；(2)互補扇區：依距離超過門檻值的條件為每個扇區找尋互補扇區群，且互補扇區依其產生之吞吐量分最佳、次佳、尚可三類；(3)外而內配對：共享資源的 D2D 設備與蜂窩設備間距離愈遠對蜂窩設備造成的干擾較少，故從最外圈的D2D設備優先搜尋共享頻段的蜂窩設備。模擬結果顯示MVS能比之前研究VCS及DRC分別提升30.1%及14%的產能。

D2D communication means direct communication between two devices without traveling through the base station. It can improve spectral efficiency, system capacity, and cellular coverage. When D2D communication share the same radio resource with cellular communication, it is called as underlay inband D2D. In underlay inband D2D, since radio resource is shared, D2D communication and cellular communication will interfere with each other. The previous resource allocation methods for mapping D2D and cellular resources is mainly based on a minimum distance threshold to reduce the interferences. That is, the distance between D2D and cellular devices must exceed the minimum distance threshold. However, exceeding the distance threshold only means that the interference between them is acceptable, but does not represent that D2D devices can get enough good bandwidth.
The thesis proposes a resource allocation method for D2D communication, called Resource Allocation with Multiple Virtual Sectors (MVS). MVS has three characteristics: (1) sector division: the coverage of base station is divided into several sectors depending on the different radiuses and angles; (2) Complementary sectors: MVS searches complementary sectors for each sector by the distance threshold and classifies complementary sectors into optimal, suboptimal and acceptable sectors by obtained throughput; (3) outer-to-inner mapping: when the distance between D2D and cellular devices is longer, the interference between them becomes less. Thus, D2D devices in outer will has a higher priority to be mapped. Finally, the simulation results show that MVS can improve 28.6% and 12.7% throughput, compared with previous work, Virtual Cell Sectoring (VCS) by 28.6% and Distance-constrained Resource-sharing Criterion (DRC) by 12.7%, respectively.

[1] A. Asadi, Q. Wang and V. Mancuso, “A survey on device-to-device communication in cellular networks,” IEEE Communications Surveys & Tutorials, vol. 16, is. 14, pp.1801-1819, November 2014.
[2] K. Doppler, M. Rinne, C. Wijting, C. Ribeio, and K. Hugl, “Device-to-device communication as an underlay to LTE-advanced networks,” IEEE Communications Magazine, vol. 47, no. 12, pp. 42-49, Dec. 2009.
[3] T. Peng, Q. Lu, H. Wang, S. Xu, and W. Wang, “Interference avoidance mechanisms in the hybrid cellular and device-to-device systems,” 2009 IEEE 20th International Symposium on Personal, Indoor and Mobile Radio Communications, pp. 617-621, 2009.
[4] S. Xu, H. Wang, T. Chen, Q. Huang, and T. Peng, “Effective interference cancellation scheme for device-to-device communication underlaying cellular networks,” 2010 IEEE 72nd Vehicular Technology Conference Fall (VTC 2010-Fall), pp. 1-5, 2010.
[5] P. Janis, V. Koivunen, C. Ribeiro, J. Korhonen, K. Doppler, and K. Hugl, “Interference-aware resource allocation for device-to-device radio underlaying cellular networks,” 2009 IEEE 69th Vehicular Technology Conference（VTC Spring）, pp. 1-5, 2009.
[6] H. Min, J. Lee, S. Park, and D. Hong, “Capacity enhancement using an interference limited area for device-to-device uplink underlaying cellular networks,” IEEE Transactions on Wireless Communications, vol. 10, no. 12, pp. 3995-4000, Dec., 2011.
[7] P. Bao and G. Yu, “An interference management strategy for device-to-device underlaying cellular networks with partial location information,” 2012 IEEE 23rd International Symposium on Personal, Indoor and Mobile Radio Communications - (PIMRC), pp. 465-470, 9-12 Sept., 2012.
[8] Rodziewicz, and Marcin, “Location-based mode selection and resource allocation in cellular networks with D2D underlay,” 2015 21th European Wireless Conference, pp.1 - 6, 2015.
[9] H. Wang and X. Chu, “Distance-constrained resource-sharing criteria for device-to-device communications underlaying cellular networks,” Electronics letters, vol. 48.9, pp. 528-530, 2012.
[10] R. Sattiraju, A. Klein, L. Ji, N. P. Kuruvatti, H. D. Schotten, C. Zhou, Ö. Bulakci, and J. Eichinger, “Virtual cell sectoring for enhancing resource allocation and reuse in network controlled D2D communication,” 2015 IEEE 81st Vehicular Technology Conference (VTC Spring), pp. 1-6, May 2015.
[11] R. Zhang, X. Cheng, L. Yang, and B. Jiao, “Interference-aware graph based resource sharing for device-to-device communications underlaying cellular networks,” 2013 IEEE Wireless Communications and Networking Conference (WCNC), pp. 140-145, 2013.
[12] X. Chen, L. Chen, M. Zeng, X. Zhang, and D. Yang, “Downlink resource allocation for device-to-device communication underlaying cellular networks,” 2012 IEEE 23rd International Symposium on Personal, Indoor and Mobile Radio Communications - (PIMRC), pp. 232-237, 2012.
[13] C.-H.Yu and O.Tirkkonen, “Device-to-device underlay cellular network based on rate splitting,” 2012 IEEE Wireless Communications and Networking Conference (WCNC), pp. 262-266, 2012.
[14] C.Xu, L.Song, Z.Han, D.Li and B.Jiao, “Resource allocation using a reverse iterative combinatorial auction for device-to-device underlay cellular networks,” 2012 IEEE Global Communications Conference (GLOBECOM), pp. 4542-4547, 2012.
[15] L. Wei, R. Q. Hu, Y. Qian, and G. Wu, “Enabling device-to-device communications underlaying cellular networks: challenges and research aspects,” IEEE Communications Magazine, vol. 52, no. 6, pp. 90-96, June 2014.