Time Reversal in Multiple-Input Multiple-Output Radar

Abstract

Abstract-Time reversal explores the rich scattering in a multipath environment to achieve high target detectability. Multiple-input multiple-output (MIMO) radar is an emerging active sensing technology that uses diverse waveforms transmitted from widely spaced antennas to achieve increased target sensitivity when compared to standard phased arrays. In this paper, we combine MIMO radar with time reversal to automatically match waveforms to a scattering channel and further improve the performance of radar detection. We establish a radar target model in multipath rich environments and develop likelihood ratio tests for the proposed time-reversal MIMO radar (TR-MIMO). Numerical simulations demonstrate improved target detectability compared with the commonly used statistical MIMO strategy.

Direction finding algorithms for time reversal MIMO radars

“…The channel is probed with f (e jω ) and the clutter backscatters rc(e jω ) are recorded. In modeling Hc(e jω ), we follow the approach presented in [4,5], where the clutter is characterized in the spatial and spectral domains, and represented as a multivariate complex Gaussian random process. The covariance matrix of the clutter returns Rr c is estimated in this step.…”

“…For the probing waveforms, we follow [4] and use the phase coding scheme Fi(e jωq ) = e j2πiq/Q F (e jωq ), for (1 ≤ i ≤ 10) and (0 ≤ q ≤ Q − 1) with Q = 10 bins, where F (e jωq ) is the DTFT of the linear frequency modulated signal…”

“…First, while the conventional MIMO radar uses a pretrained set of probing signals (generally orthogonal to each other), TR/MIMO radar adapts the transmission waveforms to the multipath environment and thus provides a straightforward procedure for adaptive waveform coding based on the channel characteristics. Recently, Moura et al [3,4] have introduced TR/MIMO radars for target detection. This paper extends the TR/MIMO radar framework, we believe for the first time, to target localization.…”

Low-Grazing Angle Target Detection and System Configuration of Mimo Radar

“…Fishler et al focused on the application of the target spatial diversity to improve detection performance and demonstrated that statistical MIMO radar provided great improvements over other types of array radars [14]. For low-grazing angle detection of MIMO radar, the authors in [15] utilized the time reversal technique in a multipath environment to achieve high target detectability. It was demonstrated that the improved target detectability can be obtained, compared with the commonly used statistical MIMO strategy.…”

Subwavelength Array of Planar Triangle Monopoles With Cross Slots Based on Far-Field Time Reversal

“…Featuring of its adaptive focusing characteristic, TR technique has been used in lots of applications such as underwater acoustics communication, medical, electromagnetic imaging, and ultra-wideband wireless communication [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19]. Recently, one completely new approach to achieve super-resolution has been offered by TR technique [20][21][22].…”