Optimizing Transmission Point Selection for Coordinated Multi-Point Transmission in LTE-Advanced Systems
| Autor: | Chun-Yuan Yang, 楊淳淵 |
|---|---|
| Rok vydání: | 2011 |
| Druh dokumentu: | 學位論文 ; thesis |
| Popis: | 99 Coordinated multiple point transmission, referred to CoMP, is one of the new features in LTE-Advanced specification and a promising technique to improve both the throughput of UEs at cell edge and overall system performance. However, coordinations among base stations incur overheads in CoMP utilization which varies depending on how many and which transmission points are involved. In this thesis, we investigate the optimal transmission points allocation problem in CoMP with the aid of the network optimization tools. To enhance UEs'' service probability, we consider the goal of maximizing the number of served UEs with satisfied QoS requirement in addition to the conventional approach which aims at maximization of the network sum capacity. We first model the basic form of those problems, and then introduce linearization transformation for constraints and linear approximation for the objective to reduce complexity. Finally we model additional overheads in CoMP as utilization penalty into our formulations. Evaluations show that CoMP can bring 12% more served UEs and 50% more sum capacity for those UEs suffered from severe interference. Moreover, we observe that for certain QoS requirements, UEs should ideally be served by multiple transmission points with comparable signal strengths rather than by its serving base station with full power consumption. Our results also reveal that typically a UE will be served by at most two transmission points in situations where CoMP obtains performance gain over single cell transmission. When signaling overhead is considered, the performance of CoMP based on sum capacity maximization degrades to that of the single cell transmission scheme, where no UE chooses to be served through CoMP scheme. CoMP based on UE number maximization, on the other hand, can still achieve a 6% gain even under the highest overheads. |
| Databáze: | Networked Digital Library of Theses & Dissertations |
| Externí odkaz: |
|