Unimodular multiple-input-multiple-output radar wave-form design with desired correlation properties

Unimodular waveforms with good correlation properties are desired for multiple-input-multiple-output radar to achieve an increased transmitting/receiving virtual aperture. In this study, a new optimisation framework is introduced to design waveforms with good correlations. It is shown that many existing waveform design problems can be incorporated into this framework. Since the considered problem is in general highly non-linear and non-convex, an iterative optimisation method based on majorisation-minimisation is developed. By carefully devising the surrogate function, the only requirement is to deal with a series of simple problems, which have closed-form solutions. The proposed algorithm can be implemented via fast Fourier transform and hence is computationally efficient. In addition, the proposed algorithm is extended to deal with spectral constraints. Numerical results demonstrate the efficiency of the proposed algorithm compared with the state-of-the-art techniques.