New Coherent and Hybrid Detectors for Distributed MIMO Radar with Synchronization Errors

We examine the impact of synchronization errors on target detection in distributed multi-input multi-output (MIMO) radar. The problem was initially considered in a recent work [1], which also introduced an approximate coherent detector (ACD). The ACD neglects the cross correlation of the radar waveforms, which may be significant in distributed MIMO radar. As the sensors are spatially distributed, the waveforms undergo different propagation delays and Doppler frequencies and thus may lose mutual orthogonality. The problem becomes more severe in the presence of synchronization errors. In this paper, we propose an improved coherent detector (CD) that takes into account the cross correlation in phase compensation and exploits different signal strength among different transmit-receive (TX-RX) paths. We also propose a new hybrid detector (HD) as a trade-off solution, in terms of detection performance and synchronization requirement, to bridge coherent detection and non-coherent detection. Numerical results are presented to illustrate the performance of existing and proposed detectors with or without synchronization errors.