High‐range‐resolution two‐dimensional imaging using frequency diversity multiple‐input–multiple‐output sonar

Distributed broadband phased‐MIMO sonar for detection of small targets in shallow water environments

“…MIMO sonar may be viewed as a type of multistatic sonar due to exploiting the spatial diversity gain. Although a general MIMO processing framework is proposed in 2006 [18], MIMO sonar develops slowly due to time‐delay spread, Doppler spread and the limited bandwidth of underwater acoustic channels [19–25]. The orthogonal waveform design has been investigated in [20, 21].…”

“…Time reversal focusing is utilised for improving the signal‐to‐noise ratio (SNR) required by MIMO detection [22, 23, 25]. The water tank experimental results have validated that the MIMO sonar can generate a high‐resolution image using frequency diversity [24].…”

Hybrid phase shift and shifted sideband beamforming for large‐aperture MIMO sonar imaging

“…In this paper we focus on the MIMO sonar with colocated elements, and without special statement we simply use MIMO sonar for short. Unlike the traditional active sonar using only one kind of waveform during a ping, the MIMO sonar emits orthogonal waveforms via all transmitting elements simultaneously [4][5][6][7][8][9][10][11][12][13][14]. At the receiving end, replicas of transmitted waveforms are utilised to matched filter echoes at each of the receiving element and hence, a great number of virtual elements are produced at the outputs of matched filters [4,5].…”

“…Multiple-input multiple-output (MIMO) sonar (also, MIMO radar) has attracted a lot of attentions in recent years [1][2][3][4][5][6][7][8][9][10][11][12][13][14]. Generally, two kinds of MIMO sonars are developed.…”

“…Generally, two kinds of MIMO sonars are developed. One is the MIMO sonar with spatially distributed elements [1][2][3], and the other is the MIMO sonar with colocated elements [4][5][6][7][8][9][10][11][12][13][14]. In this paper we focus on the MIMO sonar with colocated elements, and without special statement we simply use MIMO sonar for short.…”