密集小型基地台與裝置間通訊共存之干擾消除技術

Abstract

在小型蜂巢式基地台被電信營運商們廣泛接受之後，布建高密度的小型蜂巢式基地台相關的研究也逐漸被討論。同時裝置間的直接通訊也在3GPP中被廣泛討論，裝置間的直接通訊是個很直觀的概念，藉由直接通訊縮短距離與減少使用骨幹網路的機會 ，同時也減少傳輸路徑的損耗達到提升訊噪比與吞吐量。但在高密度的小型蜂巢式基地台與裝置間通訊共存時，許多相關的問題會產生。在這篇論文中，我們會針對高密度小型蜂巢式基地台對裝置間通訊造成的干擾做分析，並且考慮下行功率控制的極端例子，分析不同的情境來選擇該小型蜂巢式基地台是否該關閉。關閉後對於裝置間通訊可以減輕來自小型蜂巢式基地台的干擾但對於原本正在使用小型蜂巢式基地台的使用者會受到影響，但由於我們的環境是布建了高密度的小型蜂巢式基地台，所以在某些小型蜂巢式基地台被關閉的同時還有鄰近的小型蜂巢式基地台可以使用並且引入多點傳輸技術來幫助這些受到影響的使用者。結合以上兩種技術使用在高密度的小型蜂巢式基地台與裝置間通訊共存的環境可以有效提升通訊網路系統的傳輸品質。

After small cell concepts are widely accepted by telecomm operator, research about high-ly dense small cell appears in recent of years. At the same time, device-to-device (D2D) become a popular topic and discussed by 3GPP. Direct communication is an intuitive concept, decrease the usage of backbone network and shorten the distance of transmis-sion in order to enhance SINR ratio and throughput. However, many issue happened while highly dense small cell coexist with D2D. In this thesis, we will focus on interfer-ence to D2D which cause by densely small cell, analysis different scenarios and handle it. Consider the extreme case of downlink power control, different scenarios decided whether small cell should turn off or not. Turn off some small cell can mitigate interfer-ence for D2D devices but user served by those small cells who turn off will be effect and become victim. Since our environment deploy high dense small cell those user who be-come victim can still serve by neighbor small cell. Also we include coordinated mul-ti-point (CoMP) for these victim. Combination of two schemes can enhance performance in highly dense small cell coexist D2D environment.