Research On Dynamic Interference Management Technologies For 3GPP LTE System

In order to compete with WIMAX and other wireless broadband technologies and satisfy future mobile communication demand, Third Generation Partnership Project (3GPP) initiated 3G Long Term Evolution (LTE) technology standardization work at the end of 2004. The fundamental targets for LTE concern increased user data rates, improved system capacity and coverage range, reduced latency as well as reduced operator costs. But compared with 3G CDMA system, LTE system which is based on OFDM/OFDMA technology will cause more serious Inter-cell Interference (ICI). ICI can degrade the system performance and, especially, will lead to the situation with severely degraded service quality and throughput of cell edge area. Thus restraining ICI and improving the performance of cell edge region are important issues LTE facing now.In this paper, we investigate the dynamic interference management techniques of LTE system, mainly, the Inter-cell Interference Coordination (ICIC) technology for LTE multi-cell network. The details of the contribution work are summarized as follows. First, we reveal the trouble problems of ICI and Radio Resource Management RRM the LTE system facing now, and review several typical and different ICIC technologiers which have been put forward to applicate in LTE system, and also RRM framework of LTE system is analyzed.Next, based on the original static Soft Frequency Reuse (SFR) scheme, we make some improvements to develope a distributed and adaptive ICIC scheme. Compared with SFR, this ICIC scheme can implement frequency multiplexing efficiently and dynamicly to adapt to the changing user distribution and business load distribution of the network, and it significantly improves the average throughput of the cell edge users as well as the cell's total average throughput.Then, considering multimedia mixed business conditions and their different service priority levels and QoS requirements of the actual communications scene, the ICIC technology is introduced from the single-business and single QoS requirement communication scene to the multiple-business and mixed QoS requirement scene. We propose an innovative LTE ICIC scheme based on multiple user mixed business and QoS requirement. The designing of this scheme is more matched with the actual communications scenarios, which has much more effective performance. It remarkably improves the throughput of cell edge users and total throughput of the system, and guarantees users with high priority level to be able to obtain a relatively better communication experience.