Efficient Scaling Techniques for 2-D Sparse MIMO Array Far-field Imaging

For far-field 3-D imaging of 2-D sparse multiple-input-multiple-output (MIMO) array, this work analyzes the inversion model of the echo signal and proposes an efficient multi-static scaling algorithm (EMSA) without interpolation and accumulation operations. It utilizes the operational concept of frequency-modulated continuous wave (FMCW) to establish a coupling relationship between frequency and range. Through range wavenumber approximation, only some fast Fourier transform (FFT)/inverse FFT (IFFT) and phase multiplication operations are needed to realize fast 3-D imaging. Compared to the current advanced range migration algorithm (RMA) and frequency scaling algorithm (FSA), the proposed method is more efficient. In addition, a 2-D sparse MIMO imaging system in W-band is designed. Based on the simulation and experiment results, the imaging performance of the system and the effectiveness of the proposed algorithm are verified.