Photonic-Assisted Distributed MIMO Chaotic Radar Based on Multidimensional Multiplexing

A photonic-assisted distributed multiple-input and multiple-output (MIMO) chaotic radar is proposed based on multidimensional multiplexing. Reference chaotic (RC) optical signals and echo modulation signals from different remote stations (RSs) are transmitted to the central station (CS) and distinguished using wavelength division multiplexing. Signal-level fusion processing of all RSs' data and adjustment of operating frequency are simultaneously realized. Owing to the quasi-orthogonal waveform multiplexing and non-deterministic characteristics of chaotic signals, high spectrum efficiency and anti-interference capability can be ensured. Three functions, including broadband chaotic signal generation, and frequency up-and down-conversion, are integrated by polarization multiplexing. The radar becomes much more compact by sharing the laser and modulator. A distributed 2 $\times$ 2 MIMO chaotic radar with an effective bandwidth of 6 GHz in Ku-band is established, and the 2-D positions of the targets can be obtained by a back-projection algorithm. The experimental results show that the range and azimuth resolutions are 3.09 and 6.35 cm, respectively, and the average positioning error is less than 0.71 cm. A potential solution of high-precision 2-D positioning is provided for target detection in complex electromagnetic environments.