Among the approaches used to jointly estimate the directions of arrival (DOAs) of K targets in a multiple-input multiple-output dual-function radar communication system, the method based on the identification of the K largest local maxima of the modulus of the Fourier transform (FT) of the signal received by the antennas has the advantage of having a low computational cost. However, the local maxima do not necessarily correspond to the values of interest. To avoid this problem, we present an operation mode making it possible to address the estimations of the DOAs separately. To this end, we propose to design a waveform reducing the magnitudes of the signals back-scattered by the targets except the one located in a specific zone. Then, this operation mode is extended to address the case of a received signal disturbed by an additive white Gaussian noise. Finally, simulation results confirm that this approach improves the standard approach based on the FT.