Extended orthogonal matching pursuit for robust and fast target localisation in multiple-input multiple-output radar

The multiple-input multiple-output (MIMO) radar combines ultra-wide angular illumination on transmit and narrow transmission angular resolution after processing on receive. Orthogonal waveforms are needed in theory for all independent transmitters, but this property is usually not achievable in practice, therefore leading to a degraded ambiguity function. In this study, the authors focus on phase codes waveform, which gives quasi-optimal angle and range resolution. On the other hand, they induce a harmful ‘floor’ of high-level sidelobes in the range–angle domain. The authors propose to apply the orthogonal matching pursuit (OMP) to the MIMO radar signals. Therefore, it becomes theoretically possible to detect targets initially hidden by high-level sidelobes. Nevertheless, the authors identify phenomenon (grid granularity, neighbour influence) that lead to possible localisation error resulting in ghost targets. Considering this, the authors propose an extension of the OMP rejection step that includes, in addition to the expected target position, the neighbour positions within the uncertainty area. The authors show that this extension allows them to suppress the sensibility of the OMP to localisation error, even in case of very close targets. Finally, the authors demonstrate the performance of the proposed method on simulations as well as on experimental MIMO radar signals.