Abstract：To solve the cross-channel signal problem when receiving wideband radar signals with the conventional wideband digital receiver, and the blind intra-pulse modulation recognition problem for Low Probability of Intercept (LPI) radar signals, a new wideband digital receiver based on the Modulated Wideband Converter (MWC) discrete compressed sampling structure is proposed to intercept and recognize the wideband radar signals. The proposed structure uses the pseudo-random sequences to mix the received signals to baseband and other sub-bands, the mixed signals are then low-pass filtered and down-sampled to get the baseband compressed sampling data, which could solve the cross-channel signal problem flexibly. Furthermore, a recognition method based on the Short-Time Fourier Transform (STFT) and the spectrum energy focusing rate test is proposed. Firstly, the STFT spectrum bandwidth is tested to distinguish phase modulation signals and frequency modulation signals recognition roughly. Then, the spectrum energy focusing rate of the compressed sampling data is tested to recognize the intra-pulse modulation type specifically. Finally, simulation results validate the efficiencies of the proposed receiver and the proposed recognition method in low Signal-to-Noise Rations (SNR).
SONG Jun, LIU Yu, and WANG Xudong. The recognition and parameter estimation of hybrid modulation signal combined with FSK and BPSK[J]. Journal of Electronics & Information Technology, 2013, 35(12): 2868-2873. doi: 10.3724/SP.J.1146.2013.00535.
[2]
COLUCCIA A and RICCI G. About-like detection strategies to combat possible deceptive ECM signals in a network of radars[J]. IEEE Transactions on Signal Processing, 2015, 63(11): 2904-2914. doi: 10.1109/TSP.2015.2415754.
[3]
QIU Zhaoyang, WANG Pei, ZHU Jun, et al. A parameter estimation algorithm for LFM/BPSK hybrid modulated signal intercepted by Nyquist folding receiver[J]. EURASIP Journal on Advances in Signal Processing, 2016, 2016(1): 90-105. doi: 10.1186/s13634-016-0387-2.
[4]
HUANG Ling, GAO Kuangdong, He Zhiming, et al. Cognitive MIMO frequency diverse array radar with high LPI performance[J]. International Journal of Antennas & Propagation, 2016, 2016(5): 1-11. doi: 10.1155/2016/2623617.
[5]
LIU Yongjian, XIAO Peng, WU Hongchao, et al. LPI radar signal detection based on radial integration of Choi-Williams time-frequency image[J]. Journal of Systems Engineering & Electronics, 2015, 26(5): 973-981. doi: 10.1109/JSEE.2015. 00106.
[6]
GEORGE K and CHEN C I H. Multiple signal detection digital wideband receiver using hardware accelerators[J]. IEEE Transactions on Aerospace and Electronic Systems, 2013, 49(2): 706-715. doi: 10.1109/TAES.2013.6494375.
GONG Shixian, WEI Xizhang, and LI Xiang. Review of wideband digital channelized receivers[J]. Acta Electronica Sinica, 2013, 41(5): 949-959. doi: 10.3969/j.issn.0372-2112. 2013.05.019.
[8]
LAURA A, ARIAN M, MATERN O, et al. Design and analysis of compressed sensing radar detectors[J]. IEEE Transactions on Signal Processing, 2013, 61(4): 813-827. doi: 10.1109/TSP.2012.2225057.
[9]
FANG Biao, HUANG Gaoming, and GAO Jun. Sub-Nyquist sampling and reconstruction model of LFM signals based on blind compressed sensing in FRFT domain[J]. Circuits Systems & Signal Processing, 2014, 34(2): 419-439. doi: 10.1007/s00034-014-9859-5.
[10]
MISHALI M and ELDER Y C. From theory to practice: Sub-Nyquist sampling of sparse wideband analog signals[J]. IEEE Journal of Selected Topics in Signal Processing, 2010, 4(2): 375-391. doi: 10.1109/JSTSP.2010.2042414.
[11]
YU Nan, QI Xiaohui, and QIAO Xiaolin. Multi-channels wideband digital reconnaissance receiver based on compressed sensing[J]. IET Signal Processing, 2016, 7(8): 731-742. doi: 10.1049/iet-spr.2012.0086.
HU Guobing, XU Lizhong, XU Shufang, et al. Intrapulse modulation recognition of signals based on statistical test of energy focusing efficiency[J]. Journal on Communications, 2013, 34(6): 136-145. doi: 10.3969/j.issn.1000-436x.2013.06. 017.
HU Guobing, XU Lizhong, WU Shanshan, et al. Reliability evaluation for blind processing results of LFM signal based on cyclostationarity[J]. Acta Electronica Sinica, 2016, 44(4): 788-794. doi: 10.3969/j.issn.0372-2112.2016.04.006.
[14]
ZHANG Ming, LIU Lutao, and DIAO Ming. LPI radar waveform recognition based on time-frequency distribution[J]. Sensors, 2016, 16(10): 1682-1702. doi: 10.3390/s16101682.
[15]
JIANG Li, LI Lin, and ZHAO Guoqing. Polyphase coded low probability of intercept signals detection and estimation using time-frequency rate distribution[J]. IET Signal Processing, 2016, 10(1): 46-54. doi: 10.1049/iet-spr.2014. 0020.
[16]
WANG Fanggang and WANG Xiangdong. Fast and robust modulation classification via Kolmogorov-Smirnov test[J]. IEEE Transactions on Communications, 2010, 58(8): 2324-2332. doi: 10.1109/TCOMM.2010.08.090481.
[17]
KISHORE T R and RAO K D. Automatic intra-pulse modulation classification of advanced LPI radar waveforms[J]. IEEE Transactions on Aerospace and Electronic Systems, 2017, 53(2): 901-914. doi: 10.1109/TAES.2017.2667142.
LIU Zhongsheng, LI Yinwei, WEI Lideng, et al. A novel autofocus method based on short-time Fourier transform for airborne SAR[J]. Journal of Electronics & Information Technology, 2014, 36(11): 2705-2710. doi: 10.3724/SP.J.1146. 2013.02004.
[19]
KIM B, KONG S H, and KIM S. Low computational enhancement of STFT-based parameter estimation[J]. IEEE Journal of Selected Topics in Signal Processing, 2015, 9(8): 1610-1619. doi: 10.1109/JSTSP.2015.2465310.
ZHAI Xiaofei, LIU Yaxuan, CHEN Tao, et al. A fast analysis method of radar pulse modulation recognition [J]. Modern Radar, 2012, 34(6): 16-25. doi: 10.16592/j.cnki.1004-7859. 2012.06.006.
WANG Guiliang, LU Luxi, YUE Bo, et al. The circuit dictionary basis acquisition for the compressive sensing wideband receiver[J]. Acta Electronica Sinica, 2016, 44(12): 2939-2945. doi: 10.3969/j.issn.0372-2112.2016.12.018.
