Min-max waveform design for MIMO radars under unknown correlation of the target scattering

We address the problem of robust waveform design for MIMO radars when the target scattering covariance matrix is unknown at both the transmit and receive sides. Following a min-max approach, the code matrix is designed to minimize the worst-case cost under all possible target covariance matrices. Differently from previous works we include the choice of the codeword's length in the design problem. For a large class of cost functions, the min-max solution has a simple and intuitive structure which we explain. In particular, the codeword's length must be chosen as large as possible in order to provide the transmitter with the largest degrees of freedom. Examples illustrating the behavior of the min-max codes are provided for different case studies. (C) 2011 Elsevier B.V. All rights reserved.