Reducing inter-cell interference base on Dynamic Fractional Frequency Reuse (FFR) Mechanism in LTE

• Main Authors: Chien-Shiuan Chen, 陳建瑄
• Other Authors: Bih-Hwang Lee
• Format: Others
• Language: zh-TW
• Published: 2013
• Online Access: http://ndltd.ncl.edu.tw/handle/46058093939273235301

碩士 === 國立臺灣科技大學 === 電機工程系 === 101 === In the LTE system, the bandwidth will be divided by the time and frequency into many resource blocks, then user can use these different resource blocks to transmit data. Thus LTE can avoid most intra cell interference. However, due to the cell doesn’t know what the situation of resource allocation by other neighboring cell, they will make interference to each other easily, called inter cell interference. In this situation, the user who is on the cell edge will suffer more interference. Thus, there are many papers proposed to solve the inter cell interference (ICI) problem, such as: FFR (Fractional Frequency Reuse) and SFR (Soft Frequency Reuse). Although these methods can avoid interference to nearby cell through restricting the available frequency resources in their own cell’s sectors, the available resources will be reduced. In addition, when network topology have changed, these methods doesn’t adjust their frequency resources of each sector, as a result, the overall throughput will be reduced. There are some researches proposed dynamic FFR and dynamic SFR to solve aforementioned problems. Although the dynamic adjustment method can enhance the overall throughput, avoiding ICI must be considered. That is, we have to adjust neighbor cell’s frequency at the same time, this will need much of the time to exchange data or massive calculation. So we propose a simple and fast algorithm to dynamically adjust frequency resources which don’t need to adjust neighbor cell’s frequency at the same time but still can avoid ICI.