Parameter Estimation Method for High-Speed Target Using Bistatic MIMO Radar with Dual-Frequency Transmitters

Serious mismatch of matched filters, range migration, Doppler spread, and the stochastic scattering coefficient phase caused by high-speed target motion during a long integration time will result in poor parameter estimation performance of bistatic multiple-input multiple-output (MIMO) radar. In this paper, an algorithm for jointly estimating velocity, direction of departure (DOD), and direction of arrival (DOA) of high-speed target using bistatic MIMO radar with dual-frequency transmitters is proposed. Multiplication of the baseband radar return at one frequency with the conjugate of that at another closely spaced frequency is employed not only to eliminate the stochastic scattering coefficient phase, but also to remove the effect of range walk and Doppler spread. With the integration of the multiplied echo along the fast time axis, followed by a Fourier transform of the integrated signal over a slow time dimension, the unambiguous velocity of a target is estimated. The virtual array is effectively formed by using the estimated velocity to construct new matched filter coefficients, followed by the matching of received signals with the constructed coefficients. The DOD and DOA of the high-speed target can thus be estimated using the super-resolution algorithm. Some numerical experiments are provided to demonstrate the effectiveness of the proposed algorithm.