第三代UMTS系統於異質系統交接中基於系統容量的壓縮模式控制方法

Abstract

第三代手機的開發正值巔峰，而佈建之後於其他異質系統(GSM,WLAN)的交接轉換將成為一個重要的議題。由於不同系統的射頻介面皆不一致，通用行動通訊系統提出一種方法稱為壓縮模式，將中斷連線製造一段期間來量測其他系統的強度。執行壓縮模式需要提升傳輸功率來加強加速傳輸資料的可靠性。然而此提升的功率將會導致系統的效能嚴重影響，此篇論文則提出一個基於負荷量的壓縮模式，在基於能成功量測異質系統的前提下，將壓縮模式對負荷量所造成的影響降到最低。此篇內容亦建立一個通用行動通訊系統的模擬平台來模擬實際對異質系統交接的情況。而此模擬平台也成功地驗證提出的新壓縮模式演算法能確實的減少輸出功率的消耗並改善負荷量的降低。而且在量測異質系統載子的品質也都能達到令人滿意的成果。所以若實際採用此提出的演算法將可以大大提升壓縮模式的效能及效率。

The multimedia services and the high data rate transmissions have become more popular. Therefore, the third generation is developed to overlap with the existing second generation systems. To have a smooth migration in between two systems, the Inter-system handover is one of the key features in the third generation systems. The compressed mode, with variable transmission gaps and power levels, is standardized to support the inter-frequency/system handover. To minimize the use of system resources while maintaining the border-cell handover quality, a capacity-based compressed mode algorithm is proposed. Considering the tradeoff between the capacity and the connection quality, the algorithm can adaptively manages the compressed mode operation based on the potential impacts on the capacity and the efficiency of the compressed mode measurement. A simulation platform is established based on 19 UMTS cells surrounded by GSM Sea to evaluate the performance. The simulation results shows that appropriate scheduled compressed mode can reduce the power consumption and enhance the capacity while maintaining the quality of the measurements of other systems.