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    Title: 應用模糊理論於感知無線網路之動態頻道配置
    Other Titles: A fuzzy-based dynamic channel allocation scheme in cognitive radio networks
    Authors: 廖守立;Liao, Shou-Li
    Contributors: 淡江大學資訊工程學系碩士班
    顏淑惠;Yen, Shwu-Huey
    Keywords: 感知無線電;模糊理論;頻道配置;Cognitive Radio;Fuzzy;Channel Allocation
    Date: 2014
    Issue Date: 2015-05-04 09:58:42 (UTC+8)
    Abstract: 傳統無線網路中的靜態頻譜配置方式是造成頻譜使用效率不彰的主要原因之一,為了改善這個現象,出現了一種新的網路型態,稱作感知無線網路(Cognitive Radio Network, CRN),感知無線網路採用動態頻譜存取(Dynamic Spectrum Access, DSA)技術,讓網路傳輸得以在頻譜空洞(spectrum hole)間靈活的切換使用,藉此提升頻譜使用效率。本研究考量了在感知無線網路中,由於每個次要使用者(Secondary User, SU)因為所處位置以及周遭頻譜環境的不同,會有不同的可用頻道(available channel),如何配置這些可用頻道將會是影響整個系統效能的關鍵。然而在既有機制中,並未考量到多路徑衰減(multipath fading)問題,因此,本研究提出一個改良的頻道配置機制,基於模糊理論,加入次要使用者所接收訊號強度的考量,透過模糊理論的計算,制定出次要使用者頻道存取的優先權。最終,模擬結果證明了所提機制的網路吞吐量(throughput)優於既有機制,驗證了所提機制之有效性。
    In traditional wireless networks, fixed allocation of spectrum is one of the main reason causing low utilization of spectrum. In order to solve this problem, a new wireless communication model has been proposed, which called Cognitive Radio Networks (CRN). CRN adopts Dynamic Spectrum Access (DSA) technology, thus it can flexibly use the spectrum which primary user temporarily unused. In cognitive radio networks, due to each secondary user (SU) has different location and surrounding spectrum environment, it may have variety of available channels. How to assign these available channels is the crucial point of system performance. However, existing methods doesn’t consider the problem of multipath fading; therefore, this study proposed an improved channel allocation scheme. We consider the received signal strength to define the channel access priority of secondary users applied by fuzzy theory. Finally, the simulation results show the superior of our approach and verify the effectiveness of the proposed scheme.
    Appears in Collections:[資訊工程學系暨研究所] 學位論文

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