Constant-modulus partially correlated signal design for uniform linear and rectangular MIMO radar arrays

Abstract

Am ethod for generating partially correlated signals that result in arbitrary rectangular transmit beampatterns in a MIMO radar system is described. These signals are computed using frequency-offset complexe xponentials (1-D) or Kronecker products of frequency-offset complexe xponentials (2-D), followed by pointwise multiplication of the transmit signal vectors by a scalar pseudo-noise spreading sequence. Except for the spreading sequence, which can be pre-computed, the signals are giveni nc losed form and thus require no numerical optimization. The transmit beampattern shape is controlled by one scalar parameter in 1-D and twoscalar parameters in 2-D. The transmit beampattern is the convolution of a rectangle with a sincsquared function in 1-D, and the separable product of such functions in 2-D. The signals are constant-modulus, have desirable temporal autocorrelation properties, and are simple to compute.

Physical emission of spatially‐modulated radar

“…8) where it is interesting to note the lack of observable range sidelobes for the spatial modulation cases (2)(3)(4). It is important to point out, however, that this result is specific to the particular waveform and spatial modulations shown here and would differ for various waveform/spatial modulation combinations.…”

“…The received echoes are thus likewise characterised by the same waveform response regardless of spatial direction. In contrast, the notion of transmitting different, albeit correlated, waveforms from the elements of an array has been proposed [1][2][3][4][5][6][7][8][9][10][11] as a method to broaden the transmit beamwidth (i.e. beam-spoiling) for the purpose of achieving, for example, simultaneous multi-mode radar [11][12][13][14].…”

DFT-Based Closed-Form Covariance Matrix and Direct Waveforms Design for MIMO Radar to Achieve Desired Beampatterns

“…• In the second approach, the waveforms which realize the desired beampattern are directly designed without synthesizing the covariance matrix [17]. However, to the best of the authors' knowledge, optimal solutions that directly design the waveforms for a given beampattern are not available yet.…”

“…The main drawback of this algorithm is that its performance depends on the beampattern. Using the second approach, a sub-optimal algorithm to directly design the waveform for a uni-modal symmetric beampattern is presented in [17]. In this algorithm, a scalar coefficient controls the width of the beampattern.…”

Closed-form solution to directly design face waveforms for beampatterns using planar array

“…Using the second approach, which consists in directly designing the waveforms for a uni-modal symmetric beampattern, a sub-optimal algorithm is presented in [18]. In this algorithm, a scalar coefficient is chosen to control the width of the beampattern.…”