在基於正交分頻多工之第四代細胞式通訊系統中，諸如:長期演進技術及
無線都會網路標準，其細胞間之干擾為主干擾源。針對長期演進技術來削弱細
胞間干擾的三種方式為： 細胞間干擾隨機化、細胞間干擾消除及細胞間干擾協
調等。於細胞間干擾協調之方式，普遍共識是由華為公司提議的軟式頻率再使
用之技術。於過去若干年，許多提案被提出用以修正軟式頻率再使用技術於各
個層面之缺陷。然而，即使基於軟式頻率再使用之單一細胞，由蘇等人推導之
解析模型已被提出，軟式頻率再使用技術的解析模型仍尚未被完整研究。於此
論文中，我們研究以下三種基於軟式頻率再使用之情境的效能：單一細胞、單
層系統、和雙層系統。所關注的效能指標為新連結阻塞機率、連結中斷機率、
連結完成機率、和加權阻塞機率。首先，我們修正由蘇等人所提之基於軟式頻
率再使用之單一細胞解析模型。其次，我們推導基於軟式頻率再使用之單層系
統和雙層系統之解析模型。第三，我們針對不同區域推導最差的訊號干擾雜訊
比，諸如：細胞邊緣區域、細胞中央區域、以及細胞中央和邊緣交界處。第四，
證明出交界處的最差訊號雜訊干擾比，可以折衷以取得更佳的連結完成機率，
同時滿足長期演進技術細胞式通訊系統最低要求之訊號雜訊干擾比。最後，解
析結果已透過模擬結果驗證。經討論，大多數的情況，解析結果和模擬結果一
致。

In OFDM-based 4G cellular communication systems, such as Long Term
Evolution(LTE), and Worldwide Interoperability for Microwave Access(WiMAX),
inter-cell interference (ICI) is the major interference. Three main approaches for LTE to mitigate ICI are inter-cell interference randomization, inter-cell interference cancellation, and inter-cell interference coordination (ICIC). The general consensus on ICIC is the Soft Frequency Re-use(SFR) scheme proposed by Huawei. In the past few years, many proposals were presented to alleviate the drawbacks of the SFR scheme in a variety of aspects. However, the analytical model of the SFR scheme still has not been fully studied even though the analytical model of the SFR-based single cell was already developed by
Shu et al. In this work, we study the performance of SFR in three scenarios: a single cell,a one-tier system, a two-tier system. The performance measures of interest are new call blocking probability, forced termination probability, call completion probability, and weighted blocking probability. First, we refine the analytical model proposed by Shu et al. to completely describe the SFR-based single cell. Second, we develop the analytical models of SFR-based one-tier and two-tier cellular communication systems. Third, we derive the worst case SINRs for different regions, such as cell-edge region, cell-center
region, as well as the boundary between cell-edge region and cell-center region. Fourth, it is shown that the worst case SINR on the boundary can be traded off for better call completion probability while satisfying the minimum SINR requirement of LTE cellular communication systems. Last but not least, the analytical results are validated with simulation results. The analytical results are in reasonable agreement with the simulation results for most of the cases studied.

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