基于強(qiáng)散射點(diǎn)剔除的自適應(yīng)窄帶RFI抑制濾波器
doi: 10.11999/JEIT151110
基金項(xiàng)目:
國家自然科學(xué)基金項(xiàng)目(61302146)
Narrow Band RFI Suppression via Adaptive Filtering with Clipping of Strong Scatterers
Funds:
The National Natural Science Foundation of China (61302146)
-
摘要: 在低頻超寬帶合成孔徑雷達(dá)中,VHF/UHF頻段密集的窄帶射頻干擾(RFI)嚴(yán)重影響了雷達(dá)性能。常規(guī)RFI抑制濾波器在干擾頻點(diǎn)的陷波造成了寬帶信號的能量損失,抬高了點(diǎn)目標(biāo)的距離向旁瓣。該文提出一種可減小自適應(yīng)濾波器旁瓣效應(yīng)的方法:通過在距離壓縮域剔除場景內(nèi)的強(qiáng)散射點(diǎn),減小輸入信號中的寬帶目標(biāo)信號能量,提高自適應(yīng)譜線增強(qiáng)器(ALE)對窄帶干擾估計(jì)的精度,再從原始信號中減去干擾即得到目標(biāo)回波信號。這種剔除強(qiáng)散射點(diǎn)的方法利用了匹配濾波后寬帶信號與窄帶干擾的時(shí)域特性差異,能有效降低自適應(yīng)濾波器的旁瓣效應(yīng)。該文選擇歸一化最小均方誤差(NLMS)算法對剔除強(qiáng)散射點(diǎn)的自適應(yīng)窄帶RFI抑制濾波器進(jìn)行了性能評估,與傳統(tǒng)算法的對比試驗(yàn)表明該方法可在抑制RFI的同時(shí)有效減小強(qiáng)目標(biāo)的距離向旁瓣。
-
關(guān)鍵詞:
- 雷達(dá) /
- 自適應(yīng)濾波器 /
- 射頻干擾抑制 /
- 歸一化最小均方誤差算法 /
- 旁瓣抑制
Abstract: The performance of low frequency Ultra-Wide-Band (UWB) Synthetic Aperture Radar (SAR) is seriously affected by narrow band Radio Frequency Interference (RFI) in the VHF/UHF band. RFI suppression, by placing notches over the energy spectra to remove the RFI spikes, results energy loss of the wide-band signals and raises the range direction side-lobes. This paper presents an approach to suppress the side-lobe in range direction caused by adaptive filtering. After clipping main energy of strong scatterers in range compression domain before RFI estimation, the interference signals are estimated using an Adaptive Line Enhancer (ALE) and subtracted from the radar echo. The clipping approach makes use of the different time-domain characteristics between wide-band signal and narrow band interference, and by using pulse compression technology the method can be processed efficiently. To investigate the performance of RFI suppression, clipping of strong scatterers is combined to the ALE based on Normalized Least Mean Square (NLMS) algorithm. Simulation results and experimental data test compared with the conventional algorithms suggest that side-lobes of the strong scatters can be reduced effectively in RFI suppression. -
MILLER T, POTTER L, and MCCKRKLE J. RFI suppression for ultra wideband radar[J]. IEEE Transactions on Aerospace Electronic Systems, 1997, 33(4): 1142-1156. doi: 10.1109/7.625096. 董臻, 梁甸農(nóng), 黃曉濤. VHF/UHF UWB SAR基于通道均衡的RFI抑制方法[J]. 電子與信息學(xué)報(bào), 2008, 30(3): 550-553. DONG Zhen, LIANG Diannong, and HUANG Xiaotao. A RFI suppression algorithm based on channel equalization for the VHF/UHF UWB SAR[J]. Journal of Electronics Information Technology, 2008, 30(3): 550-553. LIN Yang, ZHENG Huifang, FENG Jin, et al. Detection and suppression of narrow band RFI for synthetic aperture radar imaging[J]. Chinese Journal of Aeronautics, 2015, 28(4): 1189-1198. doi: 10.1016/j.cja.2015.06.018 LI Dong, LIU Hongqing, and YANG Lisheng. Efficient time-varying interference suppression method for synthetic aperture radar imaging based on time-frequency reconstruction and mask technique[J]. IET Radar, Sonar Navigation, 2015, 9(7): 827-834. doi: 10.1049/iet-rsn.2014. 0218. CHANG Wenge, CHERNIAKOV M, LI Xiangyang, et al. Performance analysis of the notch filter for RF interference suppression in ultra-wideband SAR[C]. The 9th International Conference on Signal Processing, Beijing, 2008: 2446-2451. doi: 10.1109/ICOSP.2008.4697644. LI Tingjun, YANG Haining, and ZHOU Zhengou. RFI suppression based on phase-coded stepped-frequency waveform in through-wall radar[J]. IEEE Transactions on Geoscience and Remote Sensing, 2014, 53(3): 1583-1591. doi: 10.1109/TGRS.2014.2345514 ZHOU Hao and WEN Biyang. Radio frequency interference suppression in small-aperture high-frequency radars[J]. IEEE Geoscience and Remote Sensing Letters, 2012, 9(4): 788-792. doi: 10.1109/LGRS.2011.2181817. LUO Zhongtao, HE Zishu, and LI Jun. An effective scheme for radio frequency interference suppression in high-frequency radar[C]. Radar Conference, Arlington, 2015: 539-544. doi: 10.1109/RADAR.2015.7131057. 周峰, 邢孟道, 保錚. 基于特征子空間濾波的SAR窄帶干擾抑制方法[J]. 電子與信息學(xué)報(bào), 2005, 27(5): 767-770. ZHOU Feng, XING Mengdao, and BAO Zheng. Narrow band interference suppression for SAR using eigen subspace based filtering[J]. Journal of Electronics Information Technology, 2005, 27(5): 767-770. ZHOU Feng, TAO Mingliang, and BAO Zheng. Suppression of Narrow-band interference in SAR data[C]. International Geoscience and Remote Sensing Symposium (IGASS), Beijing, 2014: 227-230. doi: 10.1109/IGARSS.2014.6946398. VU V T, SJGREN T K, PETTERSSON M I, et al. RFI Suppression in ultrawideband SAR using an adaptive line enhancer[J]. IEEE Geoscience and Remote Sensing Letters, 2010, 7(4): 694-698. doi: 10.1109/LGRS.2010.2045633. LAMOUNT-SMITH T, HILL R D, HAYWARD S D, et al. Filtering approaches for interference suppression in low-frequency SAR[J]. IEE Proceedings: Radar, Sonar and Navigation, 2006, 153(4): 338-344. doi: 10.1049/ip-rsn: 20050092. NABIL H, CHEN Jie, KAMEL H, et al. Bidirectional notch filter for suppressing pulse modulated radio-frequency interference in SAR data[C]. International Geoscience and Remote Sensing Symposium (IGASS), Quebec City, 2014: 1136-1139. doi: 10.1109/IGARSS.2014.6946630. LORD R T and INGGS M. R. Efficient RFI suppression in SAR using a LMS adaptive filter integrated with range- Doppler algorithm[J]. Electronics Letters, 1999, 35(8): 629-630. doi: 10.1049/el:19990437. LUO X, ULANDER L M, ASKNE J, et al. RFI suppression in ultra-wideband systems using LMS filters in frequency domain[J]. Electronics Letters, 2001, 37(4): 241-243. doi: 10.1049/el:20010153. HAYKIN S. Adaptive Filter Theory[M]. 3rd edn, Upper Saddle River, NJ, Prentice-Hall, 1996: 432-438. GONG Y and COWAN C F N. A novel variable tap-length algorithm for linear adaptive filters[C]. International Conference on Acoustics, Speech and Signal Processing, Montreal, Canada, 2004: 825-828. doi: 10.1109/ICASSP.2004. 1326385. -
計(jì)量
- 文章訪問數(shù): 1643
- HTML全文瀏覽量: 168
- PDF下載量: 532
- 被引次數(shù): 0