Poly-phase codes optimisation for multi-input-multioutput radars

Multi-input-multi-output (MIMO) radar can fundamentally improve radar performance by using diversity technique. A group of specially designed signals, which usually are orthogonal, are required to be transmitted for MIMO radar obtaining excellent diversity performance. Although some well orthogonal codes have been provided, they are mostly Doppler sensitive, and their side-lobes level also need to be improved. In this study, the poly-phase codes model is presented and the optimisation problem is then analysed. An adaptive clonal selection algorithm is proposed to numerically optimise such poly-phase coded orthogonal signals. To obtain low level of aperiodic autocorrelation side lobe and cross correlation as well as good Doppler shift tolerance, sustainable Doppler shifts are introduced into the optimisation course. Numerical simulation results show the superior correlation and Doppler tolerance performances comparing with some well known codes.