在合作式通訊系統當中接收端會將訊號通過中繼點(relay) 將資料傳送出去以達到空間多樣性增益(spatial diversity gains)。在中繼點傳送資料的方式以解碼後傳送(decode-and-forward, DF) 和放大後傳送(amplify-and-forward, AF) 為主要的傳送方式。然而中繼點並不會總是可以信賴的, 當他們發生異常(misbehaving) 時將會破壞空間多樣性增益造成系統效能低落。本文希望在已知或未知異常行為的機率分佈模型之放大後傳送合作式系統下, 找到一個有效的方法進行檢測並在接收端伴隨最大比例合成(maximal ratio combing, MRC) 以達到系統之最佳效能。此外我們會以位元錯誤率分析(bit error rate, BER) 去做效能分析, 證實我們所提出的方法能對系統發生異常行為進行保護。

In the cooperative communications, the users relay each other’s signal and thus forming multiple transmission paths to the destination and therefore the system can achieve spatial diversity gain. Decode-and-forward and amplify-and-forward are the most popular relaying strategies in the literature due to their simplicity. However, in practice, cooperative users acting as relays may not always normally operated or trustworthy. When the relay misbehavior is present in
the cooperative networks, the communication performance may degrade dramatically and the users may be even better off without cooperation. Therefore, it is necessary for the destination to determine the misbehaving relays and to take appropriate actions to ensure that cooperative advantages are preserved. In this thesis, we focus on developing a misbehaving relay detection method to detect whether or not the system is in the presence of some misbehaving relays. After performing misbehaving relay detection, the destination removes the signals from the un-
reliable paths and then uses maximal ratio combing to achieve spatial diversity. The simulation results conducted by the thesis show that the proposed method is more robust as compared with those without employing misbehaving relay detection when the system is in the presence of some misbehaving relays.

1.序論 1
2.系統模型 4
2.1 放大式傳輸合作式系統模型 4
2.2 異常行為系統模型 5
3.中繼點異常行為偵測:已知機率模型 7
3.1 中央極限定理 7
3.2 貝氏檢測法則 7
3.3 能量檢測法 9
4.中繼點異常行為偵測:未知機率模型 12
4.1 Kolmogorov-Smirnov Test 12
4.2 One-Sample Kolmogorov-Smirnov Test 13
4.3 異常中繼點行為使用Kolmogorov-Smirnov Test 檢測 15
5.結果和分析 18
5.1 已知異常中繼點機率模型模擬 18
5.2 未知異常中繼點機率模型模擬 23
6.結論 28
7.附錄 31
7.1 附錄A 31
7.2 附錄B 35

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