MIMO Doppler Radar Using Khatri-Rao Product Virtual Array for Indoor Human Detection

The MIMO technique can improve system performance of not only communication system but also of radar systems. In this paper, we apply the MIMO radar with enhanced angular resolution to the indoor location estimation of humans. The Khatri-Rao (KR) matrix product is also adopted for further angular resolution enhancement. We show that the MIMO radar with the KR matrix product processing can increase the number of virtual elements effectively with suitable element arrangement, hence higher angular resolution can be realized. In general, the KR matrix product processing is not suitable for coherent radar because of signal correlation. However, when targets signals have enough Doppler frequency differential against each other, this approach works well because the signals are decorrelated. In addition, Doppler filtering is introduced to remove unwanted responses of stationary objects which make human detection difficult with conventional methods. Computer simulation and experimental results are provided to show performance of the proposed method.