針對具有可變功率比的多個重疊跳頻信號之高效能自動偵蒐鑑別流程

Efficient Automatic Acquisition Procedure for Identifying Multiple Superimposed Frequency Hopping Signals with Varying Power Ratio

黃煒哲(Wei-Che Huang)

指導教授 ： 黃正光

元智大學/電機通訊學院/通訊工程學系/碩士(2011年)

摘要

在電子戰環境中，我方常欲對敵方多網台之快速跳頻訊號以被動監聽方式進行偵搜，以達成電子反制及電子反反制之目的。然而，在現有文獻中多數演算法僅針對單網跳頻訊號之參數偵蒐進行探討。為了更符合實際傳輸訊號的狀況，本文提出兩種多網台跳頻訊號的分離法則，並且根據多網台跳頻訊號功率不同分別設計不同的參數分離法，另外搭配雙滑行視窗 (DSW) 之位準變化偵測法則以及單元平均固定錯誤警報率 (CA-CFAR) 之峰值偵測法等技術以取得各網台的跳頻頻率以及跳頻時刻等參數。
參數分離法則部分，在雙網台功率差距大時，運用交互V刻痕週譜法取得兩倍於網台數的時幅軌跡與時頻軌跡，利用時間─振幅的變化特性分離網台並且進行跳頻時刻的修正取得各網台的跳頻參數。在雙網台功率差距小時，利用時間─頻率的特性，提出一套基於時頻軌跡最大連續性的網台分離方法，網台分離後取得各網台的跳頻參數。
最後利用電腦模擬驗證此兩種針對不同情況提出的參數分離方法暨偵蒐流程的優異以及性能，並且當跳頻訊號使用GFSK調變時依然可得到相當好的性能。另一方面，使用儀器架設類似的雙網台跳頻訊號場景，再次驗證此分離法則暨參數偵蒐流程在實際應用下是可行的。

關鍵字

雙滑 ； 行 ； 視窗之位準變化偵測法則 ； 單元平均固定錯誤警報率 ； 之峰值偵測法 ； 交互V刻痕週譜法 ； 自動偵蒐鑑別流程

並列摘要

Under electronics warfare, it is highly desired to acquire the frequency hopping (FH) signal from the hostile communication or jamming system in a passive listening way. However, to the best of our knowledge there is no existing work about the acquisition of multi-net scenario in published literatures. In order to tackle the real world problem, we propose in this thesis a complete approach to FH parameters acquisition and signal separation with varying power ratio. In so doing, we also exploit the double-sliding window (DSW) technique and cell-average constant false alarm rate (CA-CFAR) technique to acquire the hopping frequencies and hoping instants for each single-net.
In the approach of parameters separation with small signal power ratio, we use the Alternating Notch-Periodogram Algorithm (ANPA) to acquire twice the number of nets’ time-amplitude traces and time-frequency traces. We then use the time-amplitude feature to separate and refine the hopping instants of individual net. When the signal power ratio becomes close to one, we use the time-frequency feature to separate the time-frequency traces with maximum continuity. After separating the time-frequency traces, we can acquire the hopping parameters. To justify and demonstrate the excellent performance of the two acquisition flows, computer simulations are included. Even though the FH signal is GFSK modulated, the proposed approaches still works well.
Finally, we set a simple two-net frequency hopping scenario to demonstrate that the two signal separation approaches are suitable for works in the real applications.

並列關鍵字

Alternating Notch-Periodogram Algorithm ； Automatic Acquisition Procedure ； Double Sliding Window ； Cell-Average Constant False Alarm Rate

參考文獻

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