在LTE-A MU-MIMO上行傳輸中的節能資源分配方法

Energy Saving Resource Allocation in LTE-A MU-MIMO Uplink

行動裝置支援行動性，使用電池運作，如何延長其續航力一直是行動裝置最被關心的研究議題；另現在MIMO (Multi-Input Multi-Output)技術已經漸漸普遍應用於無線網路中，所以本論文針對LTE-A/B4G (Long-Term Evolution-Advanced/Beyond 4G)上行多天線(MIMO)網路，研究跨MAC (Medium Access Control)層及PHY (PHYsical)層的高效節能且保證服務品質的資源排程方法，這個跨協定層方法同時考慮天線配置、傳輸功率控制、物理無線電資源分配、使用的調變與編碼等級和資料傳送與排程時所需滿足的服務品質等。MIMO技術允許使用者同時啟用多組天線，與基地台的多組接收天線同時傳輸，可獲得更高的頻譜效率，但是行動裝置啟用多組天線會增加額外耗能，也導致手機的續航力更差，因此多天線網路的節能資源配置和排程是一相當具有挑戰性的問題；考慮到LTE-A網路的排程週期僅1ms，本論文所設計的節能資源配置演算法亦兼顧即時性，同時，我們所設計的方法相容於已制定的通訊協定。藉由效能分析與模擬評估，證明所提的方法與其它的方法相比的確得到更好的效益及效能。

To support mobility, wireless mobile devices are powered by batteries; however, a battery can only store a limited amount of energy. On the other hand, MIMO (Multi-Input Multi- Output) technique is almost applied on all LTE/LTE-A (Long-Term Evolution/LTE-Advanced) devices and WiFi devices. Therefore, in this project, we are to design cross MAC-PHY layer energy-saving and QoS-guaranteed resource management and scheduling methods for LTEA/ B4G (Beyond 4G) Uplink MIMO Networks. The proposed methods have to consider antenna allocation, transmit power control, physical radio resource allocation, modulation and coding scheme selection, the scheduling of data delivery and QoS (Quality of Service) at the same time. MIMO allows mobile devices to activate multiple sets of antennas to communicate with the antennas of the base station. This results in much higher spectrum efficiency. However, devices have to consume great quantity of energy when activating multiple sets of antennas, thus leading to a shorter battery life comparing that of 3G devices. For the reasons given above, the energy-saving resource allocation and scheduling problem is more challenging. In addition, user experience is an important issue. So our proposed method considers the quality of services of mobile devices. Because of the short resource schedule period in the LTE network (only 1ms), the proposed mechanism is time efficient. Moreover, the designed scheme is compatible with the standards. By simulations, we can see that the proposed mechanism shows better performance compared to other schemes no matter in energy saving, resource utilization and QoS.