Effects on beam pattern performance for colocated multi-input multi-output radar transmitting correlated waveforms

The authors investigate the role of correlated waveforms in transmit-receive beam pattern performance of colocated multi-input multi-output (MIMO) radar, which presents many advantages by waveform diversity. The mutual orthogonality among the transmitted waveforms is often assumed but cannot be achieved in practice due to the limitation of signal duration and hardware precision. The authors introduce a common model considering the waveform correlation and propose a matched processing structure for the next estimation of parameters. The sufficient statistic for direction estimation is derived, and the transmit-receive beam pattern related to the waveform correlation matrix is obtained. This work mainly studies the effects of transmitting correlated waveforms with all kinds of correlation forms on beam pattern level. By employing these theoretical results, four numerical examples are performed further to obtain both qualitative and quantificational analyses of MIMO radar transmit-receive beam pattern performance with respect to the changing of the cross-correlation levels of the transmitted waveforms, which can provide a good guidance for orthogonal waveform design when considering MIMO radar beam patterns.