Doppler-Coded Joint Division Multiple Access Waveform for Automotive MIMO Radar

Slow-time coded waveforms are commonly used in automotive multiple-input multiple-output (MIMO) radar to achieve inter-channel spatial diversity. Typical waveforms, such as Doppler division multiple access (DDMA) and code division multiple access (CDMA), are known to suffer from Doppler ambiguity and high side lobes, respectively. In this paper, we propose a Doppler-coded joint division multiple access orthogonal waveform for automotive MIMO radar. The proposed waveform reduces the sidelobes and extends the unambiguous range of velocity by using unequal intervals for Doppler division as well. The corresponding signal processing framework is derived to correctly separate orthogonal signals. Both simulations and experimental results demonstrate the effectiveness of the proposed waveform.