無線通訊網路(Wireless Communication Network)是近代一個重要的通訊技術, 其中透過合作式通訊(Cooperative Communication) 的方法, 更是能有效改善一些無線傳輸的環境中與生俱來的缺點, 如通道衰減(Channel Fading)及多路徑干擾(Multi-Path Interference)等等。合作式通訊系統中透過中繼點(Relay Node) 的幫忙, 可以模擬達到如同MIMO(Multi-input Multi-output) 的多天線環境中之訊號多樣性(Diversity Order) 效果。然而在諸多的中繼點中, 可能存在因電路故障, 病毒入侵, 亦或是為達個人利益而發生的惡意行為(Malicious Behavior) 。在存在有惡意行為中繼點的無線網路環境中, 傳輸的效能及錯誤率會因此大打折扣, 因此在接收端就需要對應的偵測模型來改善此狀況。在本篇論文中, 我們改良了既有的軟式偵測(Soft-Detection) 方法, 進而提出硬式偵測(Hard-Detection) 決策方法。在最後的模擬結果上, 我們節省了軟決策系統帶來的硬體複雜度, 同時也改善了系統效能。

Cooperative wireless network provides a new form of transmission which can achieve antenna diversity in MIMO system but with low complexity and cost. In a cooperative system, the cooperation between source and relay leads performance improvement become obvious. However, relay’s misbehavior can degrade the performance severely. There are many reasons could cause these misbehaviors. For instance, a relay node may stop forward the received message in order to saving his energy. In addition, a machine malfunction may also cause a malicious behavior. Therefore, a mechanism to
detect the existence of misbehavior becomes necessary and important. In this paper, based on the conventional correlation-based (DB) method, we propose to apply the hard-decision values rather than the soft-decision ones for carrying out the misbehavior detection. Via simulation results, the proposed low complexity method using the hard-decision values is proved to improve the performance obtained by using CB.

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