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access icon free FMCW multiple-input multiple-output radar with iterative adaptive beamforming

This work presents the design of a frequency modulated continuous wave (FMCW) multiple-input multiple-output radar system with collocated antennas. A key part of this article is the modification and application of the iterative adaptive algorithm (IAA) for digital beamforming to an FMCW radar system. The implemented system operates in the 2.4 GHz Industry, Scientific and Medical band with 100 MHz of bandwidth and consists of a transmit (TX) site with four antennas and a receive (RX) site with four antennas. The angular resolution is greatly improved from 15° with the common delay-and-sum beamforming to only 5° with IAA beamforming, which was verified by the results from a radar simulator and by a field test with the implemented hardware. The challenge of synchronisation and maintaining phase coherence in systems with remote TX and RX sites is also addressed by proposing a low-frequency clock and trigger distribution system. This approach allows for cost-efficient systems which can be distributed over longer distances.


    1. 1)
      • 1. ‘European research project RANGER’. Available at, accessed April 2018.
    2. 2)
      • 8. Al-Qudsi, B., Joram, N., El-Shennawy, M., et al: ‘Scalable indoor positioning system with multi-band FMCW’, IET Radar Sonar Navig., 2018, 12, (1), pp. 4655.
    3. 3)
      • 12. Stoica, P., Moses, R.: ‘Spectral analysis of signals’ (Prentice Hall, New Jersey, 2005).
    4. 4)
      • 4. Kim, S., Oh, D., Lee, J.: ‘Joint DFT-ESPRIT estimation for TOA and DOA in vehicle FMCW radars’, IEEE Antennas Wirel. Propag. Lett., 2015, 14, pp. 17101713.
    5. 5)
      • 17. Pfeffer, C., Feger, R., Wagner, C., et al: ‘FMCW MIMO radar system for frequency-division multiple TX-beamforming’, IEEE Trans. Microw. Theory Tech., 2013, 61, (12), pp. 42624274.
    6. 6)
      • 9. Wagner, J., Strobel, A., Joram, N., et al: ‘FMCW system aspects for multipath environments’. 2011 8th Workshop on Positioning, Navigation and Communication, 2011, pp. 8993.
    7. 7)
      • 7. Roberts, W., Stoica, P., Li, J., et al: ‘Iterative adaptive approaches to MIMO radar imaging’, IEEE. J. Sel. Top. Signal. Process., 2010, 4, (1), pp. 520.
    8. 8)
      • 11. Bliss, D.W., Forsythe, K.W.: ‘Multiple-input multiple-output (MIMO) radar and imaging: degrees of freedom and resolution’. The Thrity-Seventh Asilomar Conf. Signals, Systems Computers, 2003, vol. 1, pp. 5459.
    9. 9)
      • 6. Li, J., Xu, L., Stoica, P., et al: ‘Range compression and waveform optimization for MIMO radar: a Cramer rao bound based study’, IEEE Trans. Signal Process., 2008, 56, (1), pp. 218232.
    10. 10)
      • 14. Huang, Y., Brennan, P.V., Patrick, D., et al: ‘FMCW based MIMO imaging radar for maritime navigation’, Prog. Electromagn. Res., 2011, 115, pp. 327342.
    11. 11)
      • 2. Biallawons, O., Klare, J., Saalmann, O.: ‘Realization and calibration of the MIMO radar MIRA-CLE Ka’, Int. J. Microw. Wirel. Technol., 2014, 6, (3–4), pp. 405413.
    12. 12)
      • 5. Lou, S., Cheng, P., Wang, Z., et al: ‘Moving target indication for multichannel FMCW SAR via iterative adaptive approach’. Proc. EUSAR 2016: 11th European Conf. Synthetic Aperture Radar, 2016, pp. 14.
    13. 13)
      • 13. Xu, L., Li, J., Stoica, P.: ‘Adaptive techniques for MIMO radar’. Fourth IEEE Workshop on Sensor Array and Multichannel Processing, 2006, pp. 258262.
    14. 14)
      • 3. Dahl, C., Vogt, M., Rolfes, I.: ‘Fractal antenna arrays for MIMO radar applications’, Int. J. Microw. Wirel. Technol., 2017, 9, (10), pp. 20192028.
    15. 15)
      • 10. Stoica, P., Li, J.: ‘MIMO radar signal processing’ (John Wiley & Sons, Inc., New Jersey, 2009).
    16. 16)
      • 15. Schmid, C.M., Pfeffer, C., Feger, R., et al: ‘An FMCW MIMO radar calibration and mutual coupling compensation approach’. 2013 European Radar Conf., 2013, pp. 1316.
    17. 17)
      • 16. Mishra, K.V., Shoshan, E., Namer, M., et al: ‘Cognitive sub-Nyquist hardware prototype of a collocated MIMO radar’. 2016 4th Int. Workshop on Compressed Sensing Theory and its Applications to Radar, Sonar and Remote Sensing (CoSeRa), 2016, pp. 5660.

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