Multiple Target Localization with Bistatic Radar Using Heuristic Computational Intelligence Techniques

We assume Bistatic Phase Multiple Input Multiple Output radar having passive Centrosymmetric Cross Shape Sensor Array (CSCA) on its receiver. Let the transmitter of this Bistatic radar send coherent signals using a subarray that gives a fairly wide beam with a large solid angle so as to cover up any potential relevant target in the near field. We developed Heuristic Computational Intelligence (HCI) based techniques to jointly estimate the range, amplitude, and elevation and azimuth angles of these multiple targets impinging on the CSCA. In this connection, first the global search optimizers, that is,are developed separately Particle Swarm Optimization (PSO) and Differential Evolution (DE) are developed separately, and, to enhance the performances further, both of them are hybridized with a local search optimizer called Active Set Algorithm (ASA). Initially, the performance of PSO, DE, PSO hybridized with ASA, and DE hybridized with ASA are compared with each other and then with some traditional techniques available in literature using root mean square error (RMSE) as figure of merit.

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Simultaneous Diagonalization Using Baseband Beamforming in mmWave MU-MIMO Systems

Electronics ◽

10.3390/electronics9111944 ◽

2020 ◽

Vol 9 (11) ◽

pp. 1944

Author(s):

Ahmad Kamal Hassan ◽

Ziaul Haq Abbas ◽

Ghulam Abbas ◽

Thar Baker

Keyword(s):

Objective Function ◽

Performance Metrics ◽

Mimo Systems ◽

Linear Optimization ◽

Multiple Input Multiple Output ◽

Ergodic Capacity ◽

Simultaneous Diagonalization ◽

Active Set ◽

Multiple Input ◽

Input Multiple Output

We consider the problem of simultaneous diagonalization of Hermitian matrices for the desired and co-channel interference terms of millimeter-wave (mmWave) multi-user multiple-input multiple-output systems. The joint unitary eigenvectors and the corresponding eigenvalues are known to assist in the mathematical tractability of key performance metrics, such as outage probability, ergodic capacity, and spectral efficiency. We formulate the signal-to-interference-plus-noise ratio in a canonical quadratic form and subsume the digital baseband beamforming vectors in the weight matrices of channels at the transmitter side. Next, a real scalar objective function is defined, which quantifies the correlation loss due to joint-diagonalization. The objective function is then maximized using baseband beamforming under the hardware constraints of the mmWave system. Through simulations, the proposed beamforming algorithm is evaluated by employing several non-linear optimization sub-routines, and it is shown that the “active-set” approach results in improved summary statistics both for the correlation metric and for the time complexity. We also reflect on the effect of optimization on the channel scatterers in mmWave systems.

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Design and Imaging of Ground-Based Multiple-Input Multiple-Output Synthetic Aperture Radar (MIMO SAR) with Non-Collinear Arrays

10.20944/preprints201703.0090.v1 ◽

2017 ◽

Author(s):

Cheng Hu ◽

Jingyang Wang ◽

Weiming Tian ◽

Tao Zeng ◽

Rui Wang

Keyword(s):

Coupling Effect ◽

Near Field ◽

Multiple Input Multiple Output ◽

Far Field ◽

Imaging Result ◽

Multiple Input ◽

Input Multiple Output ◽

Edge Points ◽

Virtual Array ◽

Field Edge

MIMO (multiple-input multiple-output) radar provides much more flexibility than the traditional radar for its ability to realize far more observation channels than the actual number of T/R (transmit and receive) elements. Designing the array of MIMO imaging radar, the commonly used virtual array theory generally assumes that all elements are placed on the same line. However, due to the physical size of the antennas and coupling effect between T/R elements, a certain height difference between T/R arrays is essential, resulting in the defocusing of edge points of the scene. On the other hand, the virtual array theory implies far-field approximation, leading to inevitable high grating lobes in the imaging result of near-field edge points of the scene observed by common MIMO array. To tackle these problems, this paper derives the relationship between target’s PSF (point spread function) and pattern of T/R arrays, by which the design criterion of near-field imaging MIMO array is presented. Firstly, the proper height between T/R arrays is designed to focus the near-field edge points well. Secondly, the far-field array is modified to suppress the grating lobes in the near-field area. Finally, the validity of the proposed methods is verified by simulations and an experiment.

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Design and Analysis of Ultra-Wideband Split Transmit Virtual Aperture Array for Through-the-Wall Imaging

International Journal of Antennas and Propagation ◽

10.1155/2013/934509 ◽

2013 ◽

Vol 2013 ◽

pp. 1-9 ◽

Cited By ~ 4

Author(s):

Biying Lu ◽

Yang Zhao ◽

Xin Sun ◽

Zhimin Zhou

Keyword(s):

Near Field ◽

Multiple Input Multiple Output ◽

Equivalence Theorem ◽

Ultra Wideband ◽

Multiple Input ◽

Spread Function ◽

Input Multiple Output ◽

Active Imaging ◽

Imaging Performance ◽

Wall Imaging

The concept of virtual aperture and the point spread function for designing and characterizing ultra-wideband near-field multiple-input multiple-output active imaging array are investigated. Combining the approach of virtual aperture desynthesis with the monostatic-to-bistatic equivalence theorem, a kind of linear UWB MIMO array, the split transmit virtual aperture (STVA) array, was designed for through-the-wall imaging. Given the virtual aperture, the STVA array is the shortest in physical aperture length. The imaging performance of the designed STVA array in the near field is fully analyzed through both numerical and measured data. The designed STVA array has been successfully applied to imaging moving targets inside buildings.

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