Spectrally-Agile Waveform Design for Wideband MIMO Radar Transmit Beampattern Synthesis via Majorization-ADMM

This paper investigates the problem of wideband multiple-input multiple-output radar transmit beampattern synthesis in a spectrally dense environment, and two optimization problems are formulated according to practical consideration. The first one is beampattern matching design under the scenario of known interference spectral band while the second addresses minimum peak sidelobe beampattern design given both interference spectral band and interference direction. In addition, to improve transmission efficiency, other than the peak-to-average power ratio constraint, a useful modulus constraint, namely, dynamic range ratio, is adopted in our development. The resultant problems are nonconvex and nonsmooth, together with multiple constraints. The advantages of the majorization-minimization and alternating direction method of multipliers (ADMM) are combined to handle them. We first use the majorization technique to handle the nonconvex and nonsmooth issues and then utilize the ADMM to solve the multi-constrained problem. Two variants of the ADMM, called majorization-ADMM and proximal-ADMM, are devised, and their convergence is also studied. Finally, numerical examples are provided to verify the effectiveness of the proposed algorithms.