結合頻率複用之LTE-A系統協調多點式傳輸之下行鏈路資源分配

Abstract

LTE-Advanced（LTE-A）為第三代合作夥伴計劃（The Third Generation Partnership Project; 3GPP）所提出之第四代通信標準．為提升系統傳輸速率與服務品質，LTE-A提出多種解決技術來實現．其中，協調多點式傳輸/接收（coordinated multipoint transmission/reception; CoMP Tx/Rx）之技術被應用於提升系統傳輸速率．又傳統的頻率複用方案無法有效的發揮該技術的優點．藉此，本篇論文考慮節能（economy）問題，提出一成本導向之協調多點式無線電資源分配（cost-oriented CoMP-based radio resource allocation; CCRRA）方法，於所提出的頻率複用格局與規則（CoMP-based frequency reuse pattern and rules; CFRPR），在滿足傳輸服務品質的條件下，在既有的無線電資源內提供最大的系統傳輸速率．再提出透過服務品質監管功能及傳輸速率分配策略（QoS policing function and rate assignment strategy），依據不同服務層級之用戶設備（user equipment），考量其被服務之緊急程度及服務該用戶設備之成本，決定服務順序及傳輸速率，並進一步提出一啟發式CCRRA演算法來分配無線電資源．啟發式CCRRA演算法主要包含了兩項功能，分別為成本最小化無線電資源分配（cost-oriented minimization radio resource allocation function; CMA）和系統吞吐量最大化無線電資源分配（throughput maximization radio resource allocation function; TMA）．模擬結果顯示，本論文所提之方法不僅能用較少的無線電資源提升系統之吞吐量，在服務品質也能獲得不錯的表現．

For the sake of providing higher transmission rate and guaranteeing the QoS (Quality of Service), 3GPP (Third Generation Partnership Project) proposed LTE-A (LTE-Advanced) to meet the objectives of IMT-Advanced 4G standard. Among several key technologies proposed for LTE-A, CoMP (Coordinated Multipoint) transmission/reception is applied to boost system performance. On the other hand, conventional frequency reuse scheme cannot make full use of the advantages of CoMP transmission/reception. Thereby, we take economy and QoS into account and proposed CCRRA (Cost-oriented CoMP-based Radio Resource Allocation) scheme and CFRPR (CoMP-based Frequency Reuse Pattern and Rules) to increase the system throughput by the least system operation cost. Through the proposed QoS policing function and rate assignment strategy, the service order and transmission rate is determined. Then, the proposed CCRRA heuristic algorithm can allocate the radio resources. In the CCRRA heuristic algorithm, it has the CMA (Cost Minimization radio resource Allocation) function and the TMA (Throughput Maximization radio resource Allocation) function to economize the expenses of the radio resources and increase the system throughputs. The simulation results show the proposed CCRRA scheme can utilize the least cost to promote system performance under considering QoS.