近年來，利用信號的週期穩態性質來做波束成型器及方位估測，
儼然成為一個嶄新的課題，因為只需所欲接收信號的週期頻率，便可求得天線的權重，以及用於方位估測所需要的矩陣，因此愈來愈受到重視。
在本文中，主要是針對利用週期穩態特性，於方位估測方面的應用加
以探討，然而一旦所欲接收信號的週期頻率發生偏差時，對於方位估測
的效能會受到嚴重的影響，故嘗試使用修正的方法，逐步修正週期頻率偏差的問題，以期能夠解決週期頻率誤差對方位估測的影響。
在陣列元件的部份，陣列天線的位置有時會因為環境的影響，而受到未知的擾動情形，在這種情形下，對於方位估測的效能，也會所影響。而在此種問題中，我們利用線性等距陣列天線的特性，使用一些合理的重建矩陣特性的方式，來修正天線陣列位置攪動所造成的影響。
最後，我們亦考慮在非理想的近場源信號入射時，循環式方位估測方式的效能，同時提出一種新的搜尋方位函數，配合FFA演算法以修正近場源所造成的效應。

Recently, bearing estimation using signal cyclostationarity
has been a new topic of great interest. By given the cycle frequency of the signals of interest, we can easily achieve
signal-selective bearing estimation without other distinctive attributes.
In this thesis, we mainly study the problems of bearing estimation using signal cyclostationarity in some nonideal conditions. At first, we consider the bearing estimation problem due to cycle frequency error. We observe that the performance of bearing estimation using signal cyclostationarity
will severely deteriorate even if there exists a small mismatch between the presumed and actual cycle frequencies. Several methods are then presented to alleviate the performance degradation due to the cycle frequency error.
On the other hand, we also consider the bearing estimation problem for cyclostationary signals when the sensor location is randomly perturbed.By restoring the inherent properties of the cyclic correlation matrices for a uniform linear array, the effect of the sensor position error on array performance can be reduced.
Finally, the bearing estimation problem in the presence of near-field cyclostationary sources is discussed. In conjunction with the FFA algorithm, we present a new bearing estimation method to effectively find the directions of these near-field cyclostationary signals.

第一章 緒論 1
第二章 陣列信號處理理論基礎及己開發之強健式波束成型技術 8
2.1節 訊號模型及理論基礎 8
2.1.1節 方位估測技術 8
2.1.2節 波束成型技術 13
2.2節 己開發之強健式波束成型技術 15
2.2.1節 極大極小法則 15
2.2.2節 一維可適性天線陣列分割處理法 17
2.2.3節 二維可適性天線陣列及架構 21
2.2.4節 二維可適性天線陣列分割處理法 23
2.3節 模擬結果 25
第三章 週期性穩態在方位估測處理之應用 39
3.1節 週期性穩態之簡介 39
3.2節 利用週期性穩態性質之方位估測法 43
3.3節 配合SSR技術在循環式方位估測的應用 46
3.4節 循環式方位估測法的進一步修正 51
3.5 模擬結果 54
第四章 在週期頻率誤差下,循環式方位估測之強健式修正法 67
4.1節 週期頻率誤差造成的影響 67
4.2節 簡介己開發之修正頻率誤差的演算法 70
4.3節 利用奇異值的批次(Batch)作法 73
4.3.1節 找sinc函數零點的作法 73
4.3.2節 配合投影方式的作法 75
4.3.3節 配合F/B方式的作法 77
4.4節 利用梯度法(Gradient)的線上(online)作法 81
4.5節 配合使用緩衝區方式修正之線上(online)作法 86
4.6節 模擬結果 88
第五章 在陣列元件位置誤差下,循環式方位估測之強健式修正法 136
5.1節 配合重建矩陣特性的修正:針對週期性穩態信號 136
5.2節 配合重建矩陣特性的修正:針對共軛週期性穩態信號 140
5.3節 模擬結果 142
第六章 考慮近場源問題時的修正法 161
6.1節 FFA修正法 161
6.2節 針對共軛週期穩態信號的進一步修正 168
6.3節 使用FFA演算法之效應 176
6.4節 模擬結果 186
第七章 結論及未來研究方向 200
參考文獻 203

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