針對兩種無線通訊系統動態頻譜分配下建立數學模型與效能分析

Abstract

動態頻譜分配能隨著多個無線網路系統在同一分享頻帶下交通量之變化做適應性的調整而增進頻譜使用效率。在此研究中，我們使用中控決策的演算法，也就是頻譜管理者週期性地重新分配頻譜給兩個無線網路系統在同一蜂巢中。我們提出兩階層的數學模型(頻譜階層模型與呼叫階層模型)來建構動態頻譜分配。我們已藉由模擬來驗證數值結果。數值結果和模擬結果顯示動態頻譜分配的效能優於固定頻譜分配的方式且我們使用近似估計及疊代演算法來完成效能分析。因此當頻譜是有限時，我們提出的數學模型及演算法能增進服務的品質。

Dynamic spectrum allocation can improve spectrum efficiency by exploiting the traffic loads variations of multiple wireless network systems, when they share neighboring band. In this study, we use a centralized approach in which a spectrum manager periodically re-allocates spectrum among two networks in a single cell. We propose a two levels model (a spectrum level model and a call level model) to characterize the dynamic spectrum allocation. We have further validated the approximated numerical results by simulations. Numerical and simulation results show that the performances of networks with the dynamic spectrum allocation are better than those with fixed allocation and complete its performance analysis via approximation and iterative approach. Hence, we conclude that our model and scheme can improve Quality of Service (QoS) of wireless networks when spectrum is limited.