A Subspace Method for MIMO Radar Space-Time Adaptive Processing

In the traditional transmitting beamforming radar system, the transmitting antennas send coherent waveforms which form a highly focused beam. In the MIMO radar system, the transmitter sends noncoherent (possibly orthogonal) broad (possibly omnidirectional) waveforms. These waveforms can be extracted by a matched interbank. The extracted signals can be used to obtain more diversity or improve the clutter resolution. In this paper, we focus on space-time adaptive processing (STAP) for MIMO radar systems which improves the clutter resolution. With a slight modification, STAP methods for the SIMO radar case can also be used in MIMO radar. However, in the MIMO radar, the rank of the jammer-and-clutter subspace becomes very large, especially the jammer subspace. It affects both the complexity and the convergence of the STAP. In this paper, a new subspace method is proposed. It computes the clutter subspace using the geometry of the problem rather than data and utilizes the block diagonal property of the jammer covariance matrix. Because of fully utilizing the geometry and the structure of the covariance matrix, the method is very effective for STAP in MIMO radar.

[1]  B. Carlson.  Covariance matrix estimation errors and diagonal loading in adaptive arrays , 1988 .

[2]  Charles R. Johnson,et al.  Matrix analysis , 1985, Statistical Inference for Engineers and Data Scientists.

[3]  D. Fuhrmann,et al.  Transmit beamforming for MIMO radar systems using partial signal correlation , 2004, Conference Record of the Thirty-Eighth Asilomar Conference on Signals, Systems and Computers, 2004..

[4]  H.A. Khan,et al.  Doppler problems in orthogonal MIMO radars , 2006, 2006 IEEE Conference on Radar.

[5]  D.W. Bliss,et al.  Waveform Correlation and Optimization Issues for MIMO Radar , 2005, Conference Record of the Thirty-Ninth Asilomar Conference onSignals, Systems and Computers, 2005..

[6]  Daniel W. Bliss,et al.  Multiple-input multiple-output (MIMO) radar and imaging: degrees of freedom and resolution , 2003, The Thrity-Seventh Asilomar Conference on Signals, Systems & Computers, 2003.

[7]  I. Reed,et al.  Rapid Convergence Rate in Adaptive Arrays , 1974, IEEE Transactions on Aerospace and Electronic Systems.

[8]  A.M. Haimovich,et al.  Eigenanalysis-based space-time adaptive radar: performance analysis , 1997, IEEE Transactions on Aerospace and Electronic Systems.

[9]  Richard Klemm,et al.  Introduction to space-time adaptive processing , 1998 .

[10]  J. Capon.  High-resolution frequency-wavenumber spectrum analysis , 1969 .

[11]  Alexander M. Haimovich,et al.  Spatial Diversity in Radars—Models and Detection Performance , 2006, IEEE Transactions on Signal Processing.

[12]  Nathan A. Goodman,et al.  On Clutter Rank Observed by Arbitrary Arrays , 2007, IEEE Transactions on Signal Processing.

[13]  Richard Klemm,et al.  Space-time adaptive processing , 1998 .

[14]  D. J. Rabideau,et al.  Ubiquitous MIMO multifunction digital array radar , 2003, The Thrity-Seventh Asilomar Conference on Signals, Systems & Computers, 2003.

[15]  H. Pollak,et al.  Prolate spheroidal wave functions, fourier analysis and uncertainty — III: The dimension of the space of essentially time- and band-limited signals , 1962 .

[16]  Wasfy B. Mikhael,et al.  Estimation of the clutter rank in the case of subarraying for space-time adaptive processing , 1997 .

[17]  Benjamin Friedlander.  A subspace method for space time adaptive processing , 2005, IEEE Transactions on Signal Processing.

[18]  D. Ramakrishnan,et al.  MIMO Radar Space-Time Adaptive Processing for Multipath Clutter Mitigation , 2006, Fourth IEEE Workshop on Sensor Array and Multichannel Processing, 2006..

[19]  P.P. Vaidyanathan,et al.  Beamforming issues in modern MIMO Radars with Doppler , 2006, 2006 Fortieth Asilomar Conference on Signals, Systems and Computers.

[20]  D. Fuhrmann,et al.  Beampattern synthesis for wideband MIMO radar systems , 2005, 1st IEEE International Workshop on Computational Advances in Multi-Sensor Adaptive Processing, 2005..

[21]  Joseph R. Guerci,et al.  Optimal and adaptive reduced-rank STAP , 2000, IEEE Trans. Aerosp. Electron. Syst..

[22]  Richard Klemm,et al.  Space-time adaptive processing : principles and applications , 1998 .