Waveform Design in MIMO Radar Using Radial Point Interpolation Method

Abstract

In this letter, we consider the problem of waveform design in colocated multiple-input multiple-output radars in order to obtain a desired beampattern. In this problem, practical constraints, such as constant envelope (CE) and low peak-to-average power ratio, are very important. Therefore, we propose a simple method to generate some practical waveforms, such as different versions of phase-shift keying and pulse-amplitude modulation. We map a non-CE to the desired finite alphabet by a mapping function (MP). In the proposed method, first, the values of cross-correlation relationship between the input and the output of MP are calculated in a few points, and then, using radial point interpolation method, the mentioned relationship and its first-order derivative are derived in the remaining points. Finally, we use the obtained derivative in order to design the desired waveform in an unconstraint problem by a gradient descend algorithm. Simulation results show that there are many different waveforms on which the proposed method can approximate the desired beampattern with a high accuracy.