标题: 第四代行动通讯异质网路具混合式可调适性保护配置之研究
Hybrid Protected Subframes Resource Allocation in LTE-A Heterogeneous Network
作者: 丁伟修
Ding, Wei-Shiou
王莅君
Wang, Li-Chun
电机学院电信学程
关键字: 具保护作用子讯框;混合式具保护作用子讯框;小型基地台涵盖范围扩展;具公平性之计量法;Protected Subframes;Hybrid Protected Subframes;Cell Range Expansion;Proportional Fair Metrics
公开日期: 2013
摘要: 在异质性网路(Heterogeneous Network, HetNet) 下, 利用Cell Range Expansion(CRE) 技术,藉由一个指定的偏差值(bias),可以有效率地将使用者从巨型细胞卸载(Offload) 至小型细胞,从而获得Cell Splitting 增益以提升系统的频谱效益。但为了保护这些经由CRE 卸载至小型细胞的使用者免于受到巨型细胞的干扰,3GPP LTE-A 于Relesase 10 提出enhanced Intercell Interference Coordination(eICIC) 技术,利用几乎空白子讯框(Almost Blank Subframe, ABS) 之具保护作用子讯框(Protected Subframes, PSF) 的架构,来降低巨型细胞对小型细胞的干
扰。然而当偏差值提高以获得更好的卸载效果时,将需要更大比例的ABS 以保护由巨型细胞卸载至小型细胞的使用者,如此虽然可以提升在小型细胞使用者的Throughput,但另一方面却也因此降低巨型细胞使用者的Throughput。相较于ABS,另一种提出的PSF 架构,即降低传送功率子讯框(Reduced Power Subframe,RPS),则是在维持巨型细胞使用者的Throughput,以及降低对小型细胞使用者的干扰间做一个取舍。因此,为了能提升小型细胞使用者的Throughput,同时能维持巨型细胞使用者的Throughput,在本篇论文中,我们提出了一个混合式具保护作用子讯框(Hybrid
Protected Subframes, HPS) 的资源分配技术,藉由结合ABS 与RPS 架构来提升位于细胞边缘地带的使用者的效能。相较于现行的技术,我们所提出的HPS 资源分配技术可以更有效率的提升系统的效能。
Cell Range Expansion(CRE) with a bias in heterogeneous network(HetNet) can encourage macro user equipment(UE) offloading to increase spectral efficiency through cell splitting. To protect offloaded UE from severe macrocell interference, a specific Protected Subframes(PSF) is introduced in the 3rd Generation Partnership Project(3GPP) Long Term Evoluction Advanced(LTE-A) Release 10. The PSF of current enhanced InterCell Interference Coordination(eICIC) is known as Almost Blank Subframes(ABS). In order to obtain the offloading benefit, a large bias for handover criteria such as Reference Signal Received Power(RSRP) needs to be used. When a large bias is applied, more victim UEs need to be protected by large ABS percentage. On the other hand, when ABS percentage increase, the throughput of pico UEs increase, but the throughput of macro UEs decrease. Therefore, in order to improve pico UEs throughout while ensuring macro UEs throughput, a new PSF pattern need to be considered. Compared to ABS, Reduce Power Subframes(RPS) which is the trade-off between the macro UEs throughput and interference of pico UEs. Thus we propose a PF-aware Hybrid Protected Subframes(HPS) resource allocation method which jointed ABS and RPS to improve the overall throughput for cell edge users. Furthermore, when HPS and Proportional Fair Scheduling(PFS) are applied, based on Proportional Fair(PF) metrics, the proposed method can adaptively reallocate HPS pattern. Compared to related work, the proposed HPS resource allocation technique can maintain the throughput as increasing HPS percentage.
URI: http://140.113.39.130/cdrfb3/record/nctu/#GT079967549
http://hdl.handle.net/11536/73989
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