Digital beamforming in MIMO-radar with frequency diversity

AbstractMIMO radars employ multiple transmitting and receiving antennae. For each transmitting antenna, an independent and easily distinguishable signal is required, and appropriate filters must be used by the receiver. For this, the transmitted signals should have characteristics, enabling their effective separation. In this paper the correlation characteristics of selected signals are compared, and the appropriate signal coding is suggested. For differentiation, we address signals with basic linear or nonlinear frequency modulation (LFM or NLFM) multiplied by Gold, PRN, or frequency diversity (FD) codes. The analysis shows that better signal characteristics are achieved using the FD than the other codes. Using matched filters with filter length of 511, sidelobes and cross-correlations are suppressed by 40 dB with FD codes, while with the other codes only 20 dB was achieved. It was also proven, that the FD codes are more tolerant to the Doppler shift. On the other hand, the FD codes application leads to an extension of the overall transmitted signal bandwidth. This however, only represents a serious barrier for very broadband radar systems.

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Research for scattering properties of spatial and frequency diversity MIMO radar targets

2008 9th International Conference on Signal Processing ◽

10.1109/icosp.2008.4697665 ◽

2008 ◽

Author(s):

Shenghua Zhou ◽

Hui Xu ◽

Liangbing Hu ◽

Hongwei Liu

Keyword(s):

Mimo Radar ◽

Frequency Diversity ◽

Radar Targets

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Array Grating Lobe Elimination of F-MIMO HF Radar with Colocated Antennas

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.556-562.4510 ◽

2014 ◽

Vol 556-562 ◽

pp. 4510-4513

Author(s):

Qiang Yang ◽

Xian Mei Hou

Keyword(s):

Multiple Input Multiple Output ◽

Pso Algorithm ◽

Mimo Radar ◽

Hf Radar ◽

Frequency Diversity ◽

Grating Lobe ◽

Multiple Input ◽

Input Multiple Output ◽

Array Structure ◽

Receive Array

Multiple-input multiple-output (MIMO) radar with frequency diversity (f-MIMO) is applied to HF radar. An array processing model of f-MIMO HF radar is developed. To eliminate the grating lobe of f-MIMO radar beamforming, two approaches are proposed. One is to apply particle swarm optimization (PSO) algorithm to select the optimal carrier frequency combination. Another is to extract array elements from the virtual receive array to get the optimal sparse array structure, and the simplified physical receive array structure is proposed. Simulation results demonstrate the effectiveness of the method proposed.

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