Discrete Grid based Detection Strategies for Distributed MIMO Radars

This paper considers the detection problem for distributed multiple-input multiple-output (DMIMO) radars under the “defocused transmit-defocused receive” (DTDR-DMIMO) operating mode. In particular, the range cells of different transmit-receive channels are not in superposition, but intersecting with each other, so the test cell, which is the cell under test (CUT) corresponding to each test, is hard to determine for jointly processing of sampling data from all channels. To address this problem, we first propose shape fitting method (SFM) to divide the surveillance area into a number of closely spaced and small size discrete grids, and determine the authentic test cells by condensing the grids, which share the same data, into one test cell. Since the number of test cells is enormous, the cost for SFM is huge. To reduce the implementation expenses, we furthermore propose homogeneously covering method (HCM) to set a smaller number of identically rectangle shaped grid cells in the surveillance area, and select the best fitted data for one grid cell by matching the range cells of every channel with this grid cell. In addition, two likelihood ratio test (LRT) detectors with constant false alarm rate (CFAR) for SFM and HCM are derived, respectively. Finally, simulation experiments have shown that both SFM and HCM can efficiently solve this problem.