Range-Doppler Clutter Suppression with Adaptive Pulse Compression by Randomized Stepped Frequency Waveform

Document Type : Original Article

Authors

1 Faculty of Electrical and Communication, University of Imam Hossein, Tehran, Iran

2 Yasin Engineering Company, Tehran, Iran

3 Faculty of Electrical and Communication Engineering, University of Imam Hossein, Tehran, Iran

Abstract

Pulse-Doppler radars typically use pulse compression and Doppler processing to detect moving targets through fast Fourier transforms. The conventional pulse compression method and the standard matched filter output for detection of small targets close to a large target do not work well, since the sidelobes of the match filter output by a large target could mask the smaller targets. Adaptive pulse compression resolves this issue significantly in noise. However, the fast targets induce Doppler phase shift in the received signal frequency, in which cause mismatch between the received signal and the transmitted signal. Consequently, the Signal to Noise Ratio is reduced. Whereas the matched filter in the radar receiver is only adapted to the transmitted signal version and its output will be wasted due to non-matching with the received signal from the environment. Adaptive pulse compression is generally applied with a single pulse in alone noise environment, but in the presence of strong clutter it is required to several return pulses. In this paper, to supply these pulses, in a radar transmitter equipped with adaptive pulse compression, waveforms diversity are generated by random frequency hopping in step frequency waveform. The simulation results of the detection of masked moving targets are compared with other conventional methods.

Keywords

Main Subjects


[1] M. I. Skolnik, Introduction to Radar Systems, 3rd ed., New York: McGraw-Hill, 2001.
[2] R. Kayvan Shokooh and M. Okhovvat, "Design and implementation of parallel matched filter bank in pulse compression radars," Journal of Passive Defence Science and Technology, vol. 1, no. 2, pp. 75-85, 2011.
[3] Z. Li, Z. Yan, S. Wang, L. Li, and M. Mclinden, "Fast adaptive pulse compression based on matched filter outputs," IEEE Trans. on Aerospace and Electronic Systems, vol. 51, no. 1, pp. 548-564, 2015.
[4] M. H. Ackroyd and F. Ghani, "Optimum mismatched filters for sidelobe suppression," IEEE Transaction Aerospace on Electronic System, vol. 2, pp. 214-218, 1973.
[5] R. Sato and M. Shinrhu, "Simple mismatched filter for binary pulse compression code with small PSL and small S/N loss," IEEE Transactions on Aerospace and Electronic Systems, vol. 39, no. 2, pp. 711 -718, 2003.
[6] D. Henke, P. McCormick, S.D. Blunt, and T. Higgins, "Practical aspects of optimal mismatch filtering and adaptive pulse compression for FM waveforms," in IEEE Intl. Radar Conf, Washington, DC, May 2015.
[7] R. Kayvan shokooh, M. Okhovvat, "Modified-adaptive pulse compression repair algorithm based on post-processing for eclipsing effects," IET Radar, Sonar & Navigation, vol. 12, no. 12, pp. 1527-1534, 2018.
[8] S. M. Kay, Fundamentals of Statistical Signal Processing: Estimation Theory, Upper Saddle River, NJ: Prentice-Hall, 1993, pp. 219-286 and 344-350.
[9] N. Levanon, "Creating Sidelobe-Free Range Zone Around Detected Radar Target," in IEEE 28-th Convention of Electrical and Electronics Engineers in Israel, 2014.
[10] S.D. Blunt and K. Gerlach, "Adaptive pulse compression via MMSE estimation," IEEE Transactions on Aerospace and Electronic Systems, vol. 42, no. 2, p. 572—584, Apr. 2006.
[11] L. Meifang and L. Kong, "Adaptive pulse compression via maximum signal minus interference level in clutter environments," in Intelligent Signal Processing and Communication Systems (ISPACS), 2010 International Symposium on. IEEE, 2010.
[12] G. Jian, Y. Huang, and Y. He, "A CFAR detector for MIMO array radar based on adaptive pulse compression-Capon filter," in Science China Information Sciences, 2011.
[13] X. Li, M. Yuehua, and X. Dingjie, ""Interference Suppression and Clutter Cancellation Based on MVDR Pulse Compression," in Instrumentation and Measurement, Computer, Communication and Control (IMCCC), 2014 Fourth International Conference on. IEEE, 2014.
[14] S. M. Kay, "Optimal signal design for detection of Gaussian point targets in stationary Gaussian," IEEE J. Sel. Topics Signal Process, vol. 1, pp. 31-41, 2007.
[15] T. Higgins, S. D. Blunt and A. K. Shackelford, "Time-range adaptive processing for pulse agile radar," in Waveform Diversity and Design Conference (WDD), 2010 International. IEEE, 2010.
[16] T. Higgins, K. Gerlach, A. K. Shackelford and S. D. Blunt, "Aspects of Non-Identical Multiple Pulse Compression," in IEEE Radar Conference, 2011.
[17] S. Liu, Y. Cao, T. -S. Yeo, W. Wu and Y. Liu, "Adaptive Clutter Suppression in Randomized Stepped-Frequency Radar," IEEE Transactions on Aerospace and Electronic Systems, vol. 57, no. 2, pp. 1317-1333, April 2021.
[18] R. Kayvan shokooh and M. Okhovvat, "An Integrated Algorithm for Optimal Detection of Weak Radar Targets Masked by the Sidelobes of Strong Target," Electronical and Cyber Defence, vol. 6, no. 4, pp. 91-105, 2019.
[19] R. Kayvan shokooh and M. Okhovvat, "Efficient Masked Target Detection by Fast Adaptive Pulse Compression Algorithm with Flexible Filter Length," Tabriz Journal of Electrical Engineering, vol. 49, no. 2, pp. 819-831, 2019.
[20] S. R. J. Axelsson, "Analysis of Random Step Frequency Radar and Comparison With Experiments," IEEE Transactions on Geosience and Remote Sensing, vol. 45, no. 4, pp. 890-904, April 2007.