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論文名稱(中文) GMSK在OFDM干擾下之循環穩態偵測問題
論文名稱(英文) Detection of GMSK signal under the Interference of OFDM signal by Using Cyclostationary Characteristics
校院名稱 成功大學
系所名稱(中) 電腦與通信工程研究所
系所名稱(英) Institute of Computer & Communication
學年度 98
學期 2
出版年 99
研究生(中文) 戴聖佑
研究生(英文) Sheng-Yu Dai
學號 q3697153
學位類別 碩士
語文別 中文
論文頁數 64頁
口試委員 指導教授-賴癸江
口試委員-蘇賜麟
口試委員-張名先
口試委員-張志文
口試委員-劉宗憲
中文關鍵字 循環穩態  合作式偵測  感知無線電  OFDM  GMSK 
英文關鍵字 Cyclostationary  Cooperation detection  Cognitive radio  OFDM  GMSK 
學科別分類
中文摘要 感知無線電系統中,當主要使用者及次要使用者同時出現時,主要使用者的通信品質會受到干擾。本論文探討當GMSK訊號為主要使用者、OFDM為次要使用者的狀況下,要如何偵測主要使用者是否進行傳輸。因為大多數調變信號的自相關函數,在時間軸為週期函數,稱之具有循環穩態的統計特性,不同調變方式的信號會有不同的循環穩態性。本文即藉此統計特性探討GMSK訊號偵測問題,並針對下列通道模型進行模擬分析:(一)GMSK訊號無外界訊號干擾的環境。(二)當GMSK訊號經過有外界干擾訊號。(三)考慮都普勒效應的狀況。(四)多路徑通道。
合作式偵測技術是基地台端接收多個局部偵測器回傳的偵測結果,以此判斷偵測訊號是否出現,希望能提高系統的偵測效能。本篇假設基地台端可完美收到局部偵測器回傳的資訊,在基地台端使用多數決或卡方檢定的方式做決策。論文中比較使用合作式偵測及單一偵測器的效能。模擬結果顯示:在高訊雜比時,多數決會比無使用合作式通訊會有較好的效能,低訊雜比則反之;而使用卡方檢定的效能皆優於使用單一偵測器。
英文摘要 In cognitive radio systems, when the primary user and secondary user exist at the same time, the communication quality of primary user will be lowered. In the thesis, we assume that the GMSK signal is the primary user and the OFDM signal the secondary user; the main topic is about detecting whether the primary user is transmitting or not. We use the property that GMSK and OFDM signals exhibit distinct cyclostationary characteristics to detect the signal of interest. We investigate the detection problem of GMSK under the following cases: (1) in the absence of OFDM signal, (2) in the presence of OFDM signal (3) with Doppler effect, (4) with multi-path channel.
We then consider the cooperative detection problem, in which the case base station receives the decisions from each local detector, and make the final decision with these local decisions. In this thesis, we assume that the base station receives the local decisions perfectly. The majority vote or chi-square test is used at the base station to make the final decision. The simulation results show that, at the high and medium SINR (signal to interference and noise ratio) situation; the performance of chi-square test is better than the one without cooperation.
論文目次 1. 研究背景 1
1.1動機 1
1.2文章結構 1
2. 文獻介紹 3
2.1循環穩態基本定義 3
2.1.1 OFDM循環穩態特性 4
2.1.2 GMSK訊號之循環穩態特性 7
2.2循環自相關函數之偵測方法 8
2.2.1第一型循環自相關函數之估計式 8
2.2.2統計檢定方法 9
3. 個人研究 11
3.1循環穩態輸入輸出關係式 11
3.1.1 OFDM訊號循環穩態之輸入輸出關係式 11
3.2偵測演算法假說 17
3.3合作式偵測模型 18
4. 模擬結果分析 22
4.1模擬參數及環境 22
4.2雜訊(noise)與干擾(interference)之影響 23
4.3改變取樣之樣本數目(以T0表之) 27
4.4改變取樣頻率 28
4.5改變快速傅利業轉換矩陣大小 29
4.6都普勒效應 31
4.6.1只有GMSK訊號經過隨機增益 31
4.6.2 OFDM及GMSK皆經過隨機增益 42
4.7多路徑通道 44
4.8合作式偵測 48
4.8.1多數決 48
4.8.2卡方檢定 48
5. 結論及未來展望 53
5.1結論 53
5.2未來展望 53
6. 附錄 54
6.1附錄(一):證明引理(一)。 54
6.2附錄(二):證明引理(二)。 56
6.3附錄(三) 59
6.4附錄(四) 62
7. 參考文獻 63
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[2] A.V. Dandawate and G.B. Giannakis, "Nonparametric Polyspectral Estimation for kth-Order (Almost) Cyclostationary Process" IEEE Transactions On Information Theory, vol.40, no.1, January 1994
[3] Menguc Oner and Friedrich Jondral, "On the Extraction of the Channel Allocation Information in Spectrum Pooling System." IEEE Journal On Selected Areas In Communcations, vol. 25, no.3, April 2007
[4] Michael F, Driscoll " An Improved Result Relating Quadratic Forms and Chi-Square Distributions " The American Statistician, vol.53, no.3, August 1999, pp,273-275
[5] Searle, S. " Linear Models" New York : Wiley, 1971
[6] D. R. Brillinger and M. Rosenblatt, “Asymptotic theory of estimates of kth-order spectra,’’ in: Spectral Analysis of Time Series, ed. B. Harris, New York Wiley, 1967, pp. 153-188.
[7] D. R. Brillinger, "Time Series: Data Analysis and Theory". San Francisco,Ca: Holden-Day, 1981
[8] C.Cordeiro; K.Challapali.; D.Birru; N.Sai Shankar, "IEEE 802.22: the first worldwide wireless standard based on cognitive radios", First IEEE International Symposium on New Frontiers in Dynamic Spectrum Access Networks, 2005. DySPAN 2005. 2005 , vol., no., pp.328-337, 8-11 Nov. 2005.
[9] William A. Gardner, "Introduction to Random Processes: with Applications to Signals and Systems, Second Edition,", McGraw-Hill, 1990
[10] Robert V. Hogg, Joseph . McKean, Allen T. Craig, "Introduction to Mathematical Statistics’ ". Pearson Prentice Hall, 2005
[11] Jarmo Lund´en, Visa Koivunen, Anu Huttunen. H. Vincent Poor, "Spectrum Sensing in Cognitive Radios Based on Multiple Cyclic Frequencies," in Proc. 2nd Int. Conf. Cognitive Radio Oriented Wireless Networks and Communications, Jul. 31-Aug. 3,2007.
[12] J. Lund´en, V. Koivunen, A. Huttunen and H. V. Poor, “Collaborative cyclostationaryspectrum sensing for cognitive radio systems,” IEEE Transactionson Signal Processing, vol. 57, no. 11, November 2009.
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