運用在LTE／LTE-Advanced第四代通訊多點協作技術下的動態協作集合組成方法

Dynamic Cooperating Set Planning for Coordinated Multi-Point (CoMP) in LTE/LTE-Advanced Systems

Coordinated Multi-Point（CoMP）是3GPP長期演進技術的主要技術之一，基地台與基地台可以組成協作集合，用來改善系統整體吞吐量以及基地台邊緣處使用者吞吐量，多數的研究都以靜態式的協作集合做討論，協作集合的大小為三個或者七個，然而面對大型活動聚集的人潮，所帶來的資料量暴增，往往使得負責該區服務的該基地台無法負荷，而靜態式的協作集合所帶來的幫助有限，且未依實際需求組成協作集合，將造成系統額外資源上的浪費，所以我們提出動態式協作集合，解決這個問題，提出的方法考慮實際的需求，動態組成協作集合來分擔過載區域的流量，不但可提升系統和基地台邊緣處吞吐量，還可以更有效利用無線資源避免協作集合無限制擴大，從我們的模擬結果可以看出，我們的方法所得到的吞吐量是靜態式CoMP的1.19倍，跟不做CoMP的基地台比起來則是1.27倍。

Coordinated Multi-Point (CoMP) is considered as one of the most important technique in 3GPP LTE/LTE-Advanced. In CoMP, several base stations can be grouped together to form the cooperating set, where the cooperating set is used to improve the system throughput as well as the throughput of cell edge users. Most of the studies discuss static cooperating set, i.e., the size of the cooperating set is fixed, such as 3 or 7. However, when big activities occur with gathered crowds, such as gala parades and New Year's Eve, the amount of wireless communication demands in such areas is over the capacity of serving base stations. In this case, the static cooperating set can bring only limited help and fails to adapt to the actual conditions. Moreover, additional communication overhead among cells is introduced but futile. In this paper, we propose the dynamic cooperating set to solve above problem. The proposed method takes the actual traffic requirement and geographical area into consideration to form dynamic cooperating set to offload the wireless communication demand. Dynamic cooperating set can not only enhance the system and cell edge throughput but also utilize the radio resource in an efficient way. The latter avoids unlimited expansion of the cooperating set. Simulation results show that the throughput of our method is 1.19 and 1.27 times of the static CoMP scheme and no CoMP scheme, respectively.