An optimizing nested MIMO array with hole-free difference coarray

Abstract

According to the newly proposed nested MIMO (Multiple-Input Multiple-Input Multiple Output Multiple Array) array design method, we propose to replace the traditional nested array into an optimizing nested array, ie, to optimizing nested MIMO array design. It not only retains the original advantage of nested MIMO array design closed expression with array element position and degree of freedom(DOF), but also greatly improves the array aperture and DOF. Optimizing nested MIMO array firstly uses the optimizing nested array as the transmitting and receiving arrays, and then make the difference set processing for the coarray of MIMO array (coarray, CA). By properly designing the array spacing of the transmitting and receiving arrays, we can obtain a non-porous difference array. When the total number of array elements is given, by analyzing the characteristics of the array structure, the best array element number of the transmitting and receiving arrays can be obtained. Simulation experiments show that compared with the nested MIMO array design, the proposed method can effectively expand the array aperture, increase the DOF, and increase the DOA estimation accuracy of the MIMO radar without increasing the number of actual array elements.

Triple Two-Level Nested Array With Improved Degrees of Freedom

“…In addition, the DTNA is first proposed by Yang et al in [14], but the DTNA [14] consists of multiple nested arrays [8]. In [21], the authors have proposed a nested MIMO array, whose equivalent array construction is the same as the DTNA in Fig. 1.…”

“…Because the number of sensors for the common TTNA should be larger than 64, we take a 20-element DTNA as a particular TTNA with H = 1. In [21], some comparison experiments of two equivalent DTNAs with smaller number of sensors have been presented. Hence, we only compare the space spectra of DTNA with other three nested arrays [8,10,11].…”

“…Recently, two kinds of sparse linear arrays, called as co-prime arrays [2][3][4][5][6][7] and nested arrays [8][9][10][11][12][13][14][15][16][17][18][19][20][21], have gained wide attention. In addition, concentric-ring isophoric sparse array [22] is another important array structure which is used widely for optimal power synthesis of beams.…”

“…However, the two kinds of nested arrays show advantages only in the DOA estimation of periodic stationary signals because of the existence of "holes". In addition to this, many other types of arrays have been proposed based on nested array, such as L-shaped nested array [17], nested arrays based on fourth-order cumulant [18,19], and nested MIMO radars [20,21].…”

Fast Direction-Finding Algorithm by Partial Spatial Smoothing in Sparse Mimo Radar

“…In [17], using the construction features of nested array [16], a nested MIMO radar [19] with hole-free difference and sum co-array (DSCA) was proposed and had higher DOF than co-prime MIMO radars [12,13]. In [20], this nested MIMO radar was improved by substituting the nested array [17] into nested array [16], and the DOF was improved further. The critical point for the use of a sparse MIMO radar is to construct an extended covariance matrix.…”