Transmit Covariance Matrix for SINR Enhancement in Colocated MIMO Radars Using Particle Swarm Optimization

For the signal-to-interference-plus-noise ratio (SINR) enhancement in colocated MIMO radars, a transmit covariance matrix (TCM) R design algorithm is proposed, employing the particle swarm optimization to overcome the drawbacks of the iterative algorithm in [1], such as being subject to terminate on a local optimum and being sensitive to the initial value. We directly transform the semi-definite constraint on R into the synthesis of R's square-root matrix U and we parameterize the mth column of U by using the coordinates of m-1 dimensional hypersphere with the same radius to replace the constraint on the R's diagonal elements. R has then been optimized to focus the transmit beampattern into the direction of target and reject the maximum number of interfering sources in the receiver. Simulation results verify the good performance of the proposed algorithm.