感知無線營運商之頻譜分享機制研究

Abstract

無線感知與動態頻譜存取可以使無線用戶共享一個廣泛可用頻譜。在感知無線電網路，次級用戶被允許存取主要用戶的通道。在本篇論文中，我們考慮通道分配問題在給定的條件限制下，針對網路運營商之間，在感知無線電網路中達到最大通道分配之吞吐量。接著我們也考慮可用的通道中的主要用戶的行為，這些可用的通道一次只能分配給一個運營商，然後我們將我們的問題對應到0-1 多個背包問題，並將此問題修改成符合我們所求的條件。 更進一步，我們設計了兩演算法來解決這個問題並將模擬結果表現出來。在第一個演算法中，我們設計出這個演算法可以非常接近最大的吞吐量。在第二個演算法中，我們設計出這個演算法可以大大的降低此問題排程的時間複雜度。最後，模擬結果表現出我們所提出來的方法可以很接近此問題的最佳解。

Cognitive radio and Dynamic Spectrum Access (DSA) enable wireless users to share a wide range of available spectra. In cognitive radio networks, secondary users are allowed to access the channels licensed to primary users. In this thesis, we consider the channel assignment problem as a resource allocation problem under some constraints for throughput maximization in cognitive radio networks over network operators. We also consider the primary user activity on available channels where each operator can be allocated at most one available channel, then we formulate our problem as a 0-1 multiple knapsack problem (0-1 MKP) which is a NP-hard problem but the constraint of our problem is different from the original problem. Moreover, we design two algorithms to solve this problem and compare their performance in the simulation results. From the simulation results, we demonstrate that the first designed algorithm achieves a high throughput performance, while with high complexity. On the other hand, the proposed second algorithm aims at significantly reducing the time complexity while it has only about 98% throughput performance, compared with the first algorithm.