Non-Orthogonality in MIMO Radar: A Fractional Fourier Approach

Unlike conventional processing, we demonstrate that separation of waveforms at the receivers is indeed possible in the MIMO and multistatic radar setting in a fractional Fourier domain. We advocate for the simultaneous transmission of linear frequency modulated (LFM) waveforms. i.e. LFM chirps. In MIMO radar literature, a frequently employed assumption (either explicit or implicit) is that: orthogonality of waveforms is maintained for all delay and for all Doppler shifts. Our mathematical proof, via several theorems and corollaries, demonstrates that two waveforms may not have zero cross-correlations for all delays and Dopplers, even when they are strictly orthogonal.