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

• Main Authors: Wei-Che Huang, 黃煒哲
• Other Authors: 黃正光
• Format: Others
• Language: zh-TW
• Published: 2011
• Online Access: http://ndltd.ncl.edu.tw/handle/77714178413106255111

碩士 === 元智大學 === 通訊工程學系 === 99 === 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.