頻譜感測機制是感知無線電網路中最重要的功能之一。當不具使用執照的次要使用者要使用需有執照的頻帶時，次要使用者必須先進行頻譜感測，判斷擁有執照的主要使用者是否存在，以避免干擾主要使用者而損害其權益。雖然配置感知無線電的裝置已擁有頻譜感知的能力，由於環境中存在通道衰減效應，以及硬體本身的諸多限制，使用協同式的機制可在頻譜感測上獲得更好的效能。本篇論文提出了一個基於鄰居資訊的協同式頻譜感測機制，藉由蒐集鄰居的偵測結果並計算其比例，次要使用者可分散式地根據其比例得到更正確的偵測結果。而此機制亦可用在規模較大而存在兩種偵測結果的網路中，次要使用者仍可使用上述的機制，正確判斷出自己位於哪個區域。當有不同的效能需求時，本篇論文亦提供兩個進階機制。模擬結果顯示，此機制藉由使用鄰居的資訊，能有效的將錯誤率自22.61% 降至6.81%。

In cognitive radio networks (CRNs), spectrum sensing is one of the most important functions. If unlicensed secondary users (SUs) need to use the licensed bands, it is necessary for SUs to sense the spectrum to detect the existence of the licensed primary user (PU) to avoid interference with licensed usage of spectrum. Although cognitive radio devices have the capacity to sense the spectrum, due to the fading effects in the environment and hardware limitations, it is preferable to use cooperative methods to obtain better spectrum sensing performance. In this thesis, a neighborhood-based cooperative spectrum sensing (NCS) mechanism is proposed. Using the proportion of neighbors claiming the PU is absent, each SU could make a more proper decision of spectrum sensing without a fusion center. Moreover, NCS can be used even if the network is large scale and the boundaries of PU cross the network. Alternative versions of NCS are also provided when the different performance is needed. The simulation results show that the error rate can be effectively reduced from 22.61% to 6.81%.

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