Multistatic MIMO Sparse Imaging Based on FFT and Low-Rank Matrix Recovery Techniques

Abstract

This paper proposes a simple sparse imaging scheme of using a linear sparse aperiodic array and a new fast Fourier transform (FFT) matched filtering algorithm for a THz multistatic multiple-input and multiple-output (MIMO) imaging system. The simple linear sparse aperiodic array and mutlipass interferometric synthetic aperture focusing technique are used to achieve a fast sampling, low system cost and high imaging performance. Unlike a traditional generalized synthetic aperture focusing technique (GSAFT) for multistatic MIMO imaging, which is time consuming and exhibits increased reconstruction time with increased data volume, the proposed FFT matched filtering (FFTMF) image reconstruction algorithm is capable of providing comparable image quality but significantly reducing the reconstruction time. For example, we show that for an image of 300 mm × 320 mm with a pixel size of 0.75 mm × 0.83 mm, the reconstruction time is reduced from about 1.50 minutes to 0.25 s in the 220 GHz 5-pass synthetic imaging experiments. The proposed imaging algorithm uses an internal zero padding, a multipass interferometric synthetic aperture focusing technique and a wideband imaging technique to improve the imaging performance under a low-cost, sparse sampling scheme. It shows a strong anti-noise ability and a high tolerance to target focusing distance. In addition, integrated with a algorithm of principal component pursuit by alternating directions method (PCPADM), sparse imaging is available to further save system cost and sampling data without a loss of image quality while the novel use of error matrix provides an additional detection capability for imaging systems.

MIMO Coded Generalized Reduced Dimension Fourier Algorithm for 3-D Microwave Imaging

“…The scheme of simultaneous transmission of orthogonal signals by multiple Txs was used only for sensing. In the current model, it is possible to extract the channel transfer function on the Rx side (mathematically, in (8), an estimate of…”

“…Due to the orthogonality property in the matrix W ɶ , an estimate of the channel transfer function can be obtained from (8) in the following form:…”

“…Fig. 15 shows the reconstructed images by the generalized synthetic aperture focusing technique (GSAFT) [8,59], the method [16] and the proposed algorithm. The target image is clearly identifiable in all three outputs.…”

“…This usually requires a very large number of antenna elements to satisfy the Nyquist criterion [4]. The use of sparse aperiodic phased arrays [5,6] and multistatic multiple-input multiple-output (MIMO) arrays [7,8] are two solutions provided for this issue. It has been demonstrated that the high spatial information diversity obtained by antenna arrays with a MIMO configuration can lead to an increase in the quality of reconstructed images in an imaging system [9,10].…”

Fast image reconstruction for near-field terahertz imaging with multistatic non-uniform sparse arrays

“…Using some types of multiple-input multiple-output (MIMO) arrays is a suitable option to reduce the number of elements [14][15][16]. In particular, sparse periodic arrays (SPAs) with large inter-element spacing have recently been proposed for multistatic MIMO THz imaging systems [16][17][18]. However, the special multistatic structure of SPA is such that it is not possible to directly apply conventional fast Fourier transform (FT)-based image reconstruction techniques in the nearfield (NF) [19,20].…”