隨著頻帶需求的增多，感知無線電的技術使得非註冊的裝置或用戶可以機會性地使用閒置的已註冊頻帶，從而改善頻帶的使用效益。另外，合作式通訊是一種能夠提升網路傳輸效能的技術。然而，目前把合作式通訊應用在感知無線網路的文獻，大都是考慮終端節點能直接跟基地台溝通的環境。在感知無線電隨意網路環境下，可用的頻帶資源會隨著時間或地理位置而隨時改變。這種特性使得多跳合作式路由成為重要的研究議題。在這篇論文裡，我們把合作式通訊應用在感知無線電隨意網路，並且提出一個合作式的路由協定。為了達成目的，我們採用按需要路由的方式去找出任何來源端到目的端之間的最少成本路徑，同時並找到路徑當中節點和節點之間最適合作為合作式傳輸的中繼節點。我們所定義的用來評估成本和選擇中繼節點的一些效能指標，將考量到不同感知用戶在同通道會有不同可用頻寬等感知網路特有的性質。經由模擬結果顯示，我們所提出的合作式路由協定相對於過往的文獻，除了有較高的端到端吞吐量外，也減少了端到端的延遲時間和控制訊息的負擔。

Cognitive radio (CR) technology enables the opportunistic use of the vacant licensed fre-quency bands, thereby improving the spectrum utilization. Cooperative communication is another promising technique that it can increase the capacity of relay links, and also brings some benefits in wireless networks. Recently, most of researches applying cooperative com-munications in CR networks are on infrastructure communications. Therefore, considering end-to-end throughput in CR ad-hoc networks is an important research issue because the availability of local spectrum resources may change frequently with the time and node loca-tions. In this thesis, we propose a cooperative routing protocol in CR ad-hoc networks. An on-demand routing protocol is used to find an end-to-end minimum cost path between a pair of source and destination. We define some performance metrics to estimate the maximum achievable capacity and transmission cost between two nodes with cooperative improvement via a relay. The simulation results show that our proposed cooperative routing protocol not only obtains higher end-to-end throughput, but also reduces the end-to-end delay and the amount of control messages compared to previous work.

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