隱藏於強海雜波下基於Burg方法之高解析度頻譜估測之高效率硬體實現

本論文主要實現隱藏於強海雜波下AR 高解析度頻譜估測 (Autoregressive High-Resolution Spectrum Estimation)之Burg方法與誤警報偵測器CFAR (Constant False Alarm Rate)，對雷達回波之都卜勒頻譜進行分析偵測。我們藉由MATLAB軟體模擬現有的演算法並與Xilinx之System Generator的電路設計工具，所建構系統之模擬結果做軟硬體相互驗證。在本論文我們採用較高精確度的方式來實現Burg估測法與CFAR偵測器，以得到較好的估測性能。首先我們電路設計以FIR- Lattice濾波器架構下完成八階AR-Burg演算法得到相對應的反射係數，並設計利用八階IIR濾波器與FFT快速傅立葉轉換計算頻譜，以有效地得到高解析度的頻譜訊號，進而在CFAR偵測器中估測。最後，我們將硬體模擬結果與軟體MATLAB模擬相互對應比較，驗證兩者模擬結果十分一致，能精確高效率分辨出雜波及低速目標之頻譜特性，並提升低速目標之偵測性能。

關鍵字

海雜波； AR 高解析度頻譜估測； IIR濾波器； AR-Burg演算法；誤警報偵測

並列摘要

This thesis aims to realize the autoregressive high-resolution spectrum estimator based on the Burg method and constant false alarm rate (CFAR) detection for analyzing the Doppler spectrum from the radar echo over strong sea clutters. We adopt the software/hardware co-simulation approach to design the high-resolution spectrum estimator by using the MATLAB software and System Generator tool. The better estimation performance can be achieved by using the Burg-algorithm-based high-resolution spectrum estimation instead of using the traditional moving target identification (MTI) method in the radar signal processing. As for the hardware implementation, the design steps are described as follows. First, we design the finite-length-response-Lattice (FIR-Lattice) filter framework to realize the AR-Burg algorithm architecture with eight-order. In doing so, the reflection factors and filter coefficients of the AR-Burg algorithm can be obtained. Second, the hardware of the infinite-length response (IIR) with eight-order and fast Fourier transform (FFT) is designed to obtain the frequency contents of the radar echo over the strong sea clutters. Third, the CFAR detector is designed to determine whether the target in the sea exists. Finally, we verify the correctness of the co-simulation approach by comparing the simulation results of the MATLAB and those from the System Generator outputs. Simulation results show that the software/hardware results are very consistent with each other. Therefore, the proposed algorithm is proved to have high-accuracy estimation accuracy and to improve the detection performance.

並列關鍵字

sea clutters ； high-resolution spectrum estimation ； IIR filter ； AR-Burg ； CFAR

參考文獻

[1] E. Jakeman and P. N.Pusey, “A Model for Non-Rayleigh Sea Clutter,” IEEE Trans. on Ant. Prop., pp. 806-814, 1976.

[2] C. J. Oliver, “Correlated K-distributed Clutter Models,” Optica Acta, pp. 1515-1547, 1985

[3] K. D. Ward, “Compound Representation of High Resolution Sea Clutter,” Electronics Letters, vol. 17, pp. 561-563, 1981.

[4] L. J. Marier Jr., “Correlated K-Distributed Clutter Generation for Radar Detection and Track,” IEEE Transactions on Aerospace and Electronic Systems, vol. 31, pp. 568-580, Apr. 1995.

[6] H. C. Chan, “Radar sea-clutter at low grazing angles,” IEE Proceedings F - Radar and Signal Processing, vol. 137, pp. 102-112, Apr. 1990.

國際替代計量

隱藏於強海雜波下基於Burg方法之高解析度頻譜估測之高效率硬體實現

全文下載

主題瀏覽