Transmit beampattern synthesis for sub-arrayed MIMO radar

Sub-arrayed multiple-input multiple-output (MIMO) radar is a new architecture of MIMO radar, which can exploit jointly the benefits of the coherent processing gain and waveform diversity, and has received extensive attention of researchers. An approach to synthesize the desired transmit beampattern for sub-arrayed MIMO radar is proposed in this paper. The essence of this approach is that the transmit beampattern is equal to the weighted sum of sub-arrays' beampatterns. First the beam-pattern of each sub-array with certain steering direction and low side lobe level is obtained by using traditional constrained optimization technique. Then under the constant total transmit energy constraint, convex optimization technique is utilized to design the optimal weight of each sub-array's beampattern, so that the synthesized beampattern can approximate the desired transmit beampattern exactly. Both analytical and simulation results validate the effectiveness of the proposed approach.