在本論文中，我們透過賽局理論 (game theory) 來解決感知無線電 (cognitive radio) 網路間的頻譜交易議題。在我們所提出的架構中，使用適應性調變的有執照系統可以在不中斷傳輸的情況下將部份頻譜交易給無執照系統，而無執照系統可以向有執照系統要求功率進行傳輸。因此，主要用戶將決定如何在儘可能不損及己身效能下制定最佳的交易價格來使獲利達到最大，而次要用戶將決定傳輸功率的配置來以最少的費用達到最佳的傳輸效能。由模擬結果顯示，我們所提出的頻譜交易模型能以分散式方法收斂到唯一的奈許平衡點 (Nash equilibrium)，而次要用戶也能在對主要用戶造成輕微的影響下進行傳輸。此外，針對我們提出的架構下所得到的奈許平衡點，其存在與唯一的特性我們也做了證明。最後，一些未來可以進行的相關研究議題置於本論文之末。

In this thesis, we address the issue of spectrum leasing in the cognitive radio (CR) networks through a game-theoretical approach. In the proposed game model, the primary system using adaptive modulation schemes can lease the licensed spectrum to the secondary one on the condition of not being dropping out, while a secondary system can request an amount of power to transmit in the channel which is leased from the primary one. Thus, a primary user (PU), as being a seller, can determine the optimal leasing price to maximize its revenue at a cost of minimal throughput degradation. Meanwhile, a secondary user (SU), as being a buyer, can allocate the optimal transmission power to maximize its throughput at a minimum payment. As illustrated by the simulation results, the proposed spectrum leasing game can converge to a unique Nash equilibrium in a decentralized way, and the SUs can have chances to transmit causing slight impacts on the transmission modes of the PUs. Moreover, to verify the proposed spectrum leasing game, the existence and uniqueness of the Nash equilibria are also proved. Some interesting research topics for the future are listed at the end of this thesis.

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