scholarly journals A Fast 3D Near Range Imaging Algorithm for a Scanning Sparse MIMO Array in the Millimeter Band

Sensors ◽  
2020 ◽  
Vol 20 (17) ◽  
pp. 4701
Author(s):  
Feifan Wang ◽  
Bin Deng ◽  
Qi Yang ◽  
Hongqiang Wang ◽  
Ye Zhang
Keyword(s):  
Imaging Techniques ◽  
Multiple Input Multiple Output ◽  
Range Imaging ◽  
Imaging Algorithm ◽  
Multiple Input ◽  
Input Multiple Output ◽  
Imaging Performance ◽  
Array Imaging ◽  
The Impact ◽  
Mimo Arrays

Millimeter-wave technology has been widely used in near range targets imaging scenarios, such as mechanical scanning and multiple input multiple output (MIMO) array imaging. Emerging scanning array regimes increase the need for fast-speed and high-quality imaging techniques, which, however, are often subject to specific array positions. Moreover, the relationship between array positions and the imaging performance is not clear, which leads to no uniform standard for array design. In this paper, a series of array configurations are designed to explore the impact of different array positions on the cross-range imaging performance. Meanwhile, a novel fast fully focused imaging algorithm with wavenumber domain properties is presented, which is not constrained by the positions of the transmitters and receivers. Simulation and experimental results show that, compared with a conventional algorithm, the proposed algorithm has a faster imaging speed under the same imagining quality. This study provides a feasible method for fast fully focused imaging in the case of location-constrained MIMO arrays, or partially damaged transceivers.

scholarly journals MIMO SAR FORMATIONS: ORBITAL DIAMETER AND SYNCHRONIZATION TOLERANCES

2020 ◽  
Vol XLIII-B1-2020 ◽  
pp. 631-635
Author(s):  
A. Monti Guarnieri ◽  
D. Giudici ◽  
P. Guccione ◽  
M. Manzoni ◽  
F. Rocca
Keyword(s):  
Pulse Repetition Frequency ◽  
Multiple Input Multiple Output ◽  
Cost Effective ◽  
Power Resources ◽  
Multiple Input ◽  
Input Multiple Output ◽  
Single Input ◽  
Small Antenna ◽  
Along Track ◽  
The Impact

Abstract. Multiple-Input-Multiple Output (MIMO) Synthetic Aperture Radar (SAR) along-track formations can be used to fraction the power resources into compact, lightweight and cost-effective satellites, or to extend the swath coverage beyond the limit provided by a small antenna. In this second case, the Pulse Repetition Frequency (PRF) is kept low by implementing an inversion that solves up to N−1 ambiguities, given N observations. The simultaneous illumination – that allows for the N² gain due to the coherent combination of the N transmitters and the N receivers, is analyzed and shown not to be critical, as the more than N=2 sensors are assumed. Performance is evaluated for the N=2 and N=3 cases and compared with the Single Input Multiple Output formations, where one sensor is transmitting, and all are receiving. Finally, the impact of the across-track deviation from the orbit is modeled and evaluated.

scholarly journals Impact of Probe Configurations on Maximum of Test Volume Size in 3D MIMO OTA Testing

2017 ◽  
Vol 2017 ◽  
pp. 1-9 ◽  
Author(s):  
Weimin Wang ◽  
Huaqiang Gao ◽  
Yongle Wu ◽  
Yuanan Liu
Keyword(s):  
Channel Model ◽  
Multiple Input Multiple Output ◽  
Maximum Size ◽  
Test Volume ◽  
Multiple Input ◽  
Input Multiple Output ◽  
3D Mimo ◽  
Flexible Probe ◽  
The Impact ◽  
Volume Size

With the development of multiple-input-multiple-output (MIMO) technology, the over-the-air (OTA) testing of MIMO capable devices with different sizes needs to be conducted for performance evaluation. The device under test (DUT) should be within a tridimensional test volume created by multiprobe configurations. Thus, determining the maximum size of test volume could be vital to test the DUT of different size and larger test volumes should be adopted to evaluate larger DUTs. All types of probe configurations including the fixed and the flexible probe configurations are investigated in this paper to address this issue. The maximum of test volume size (MTVS) is determined within the given error threshold of spatial correlation for a given probe configuration. Simultaneously, the impact of different probe configurations on MTVS is studied in order to obtain larger MTVSs. Simulation results show that larger MTVSs can be obtained by utilizing the optimal probe configuration with any given 3D channel model for 3D MIMO OTA testing.

scholarly journals Ultra-Wideband MIMO Array for Penetrating Lunar Regolith Structures on the Chang’e-5 Lander

Electronics ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 8
Author(s):  
Wei Lu ◽  
Yuxi Li ◽  
Yicai Ji ◽  
Chuanjun Tang ◽  
Bin Zhou ◽  
...  
Keyword(s):  
Lunar Regolith ◽  
Multiple Input Multiple Output ◽  
Ultra Wideband ◽  
Detection Depth ◽  
Multiple Input ◽  
Input Multiple Output ◽  
Operating Bandwidth ◽  
Exploration Mission ◽  
The Impact ◽  
Vivaldi Antennas

The Chang’e-5 lunar exploration mission of China is equipped with a Lunar Regolith Penetrating Radar (LRPR) for measuring the thickness and structures of the lunar regolith in the landing area. Since the LRPR is stationary, an ultra-wideband multiple-input multiple-output (MIMO) array is designed as a replacement for conventional mobile subsurface probing systems. The MIMO array, with 12 antenna elements and a switch matrix, operates in the frequency band from 1.0 to 4.75 GHz. In this work, the design and layout of the antenna elements were optimized with respect to the lander. To this end, the antenna elements were designed as miniaturized Vivaldi antennas with quarter elliptical slots (i.e., quarter elliptical slotted antenna, or QESA). QESAs are significantly small while being able to mitigate the impact of the lander on antenna electrical performances. QESAs also have a wide operating bandwidth, flat gain, and excellent time domain characteristics. In addition, a high-temperature resistant ultra-light radome with high transmissivity is designed to protect the external antenna array. After calibration, the MIMO array is used to detect targets embedded in volcanic ash. The detection depth reaches 2.5 m, and the detection effect is good.

scholarly journals Impact of Stair and Diagonal Matrices in Iterative Linear Massive MIMO Uplink Detectors for 5G Wireless Networks

Symmetry ◽  
2020 ◽  
Vol 12 (1) ◽  
pp. 71 ◽  
Author(s):  
Mahmoud A. Albreem ◽  
Mohammed H. Alsharif ◽  
Sunghwan Kim
Keyword(s):  
Computational Complexity ◽  
Iterative Methods ◽  
Mimo Systems ◽  
Multiple Input Multiple Output ◽  
Low Complexity ◽  
Matrix Inversion ◽  
Multiple Input ◽  
The Matrix ◽  
Input Multiple Output ◽  
The Impact

In massive multiple-input multiple-output (M-MIMO) systems, a detector based on maximum likelihood (ML) algorithm attains optimum performance, but it exhaustively searches all possible solutions, hence, it has a very high complexity and realization is denied. Linear detectors are an alternative solution because of low complexity and simplicity in implementation. Unfortunately, they culminate in a matrix inversion that increases the computational complexity in high loaded systems. Therefore, several iterative methods have been proposed to approximate or avoid the matrix inversion, such as the Neuamnn series (NS), Newton iterations (NI), successive overrelaxation (SOR), Gauss–Siedel (GS), Jacobi (JA), and Richardson (RI) methods. However, a detector based on iterative methods requires a pre-processing and initialization where good initialization impresses the convergence, the performance, and the complexity. Most of the existing iterative linear detectors are using a diagonal matrix ( D ) in initialization because the equalization matrix is almost diagonal. This paper studies the impact of utilizing a stair matrix ( S ) instead of D in initializing the linear M-MIMO uplink (UL) detector. A comparison between iterative linear M-MIMO UL detectors with D and S is presented in performance and computational complexity. Numerical Results show that utilization of S achieves the target performance within few iterations, and, hence, the computational complexity is reduced. A detector based on the GS and S achieved a satisfactory bit-error-rate (BER) with the lowest complexity.

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

2013 ◽  
Vol 2013 ◽  
pp. 1-9 ◽  
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.

scholarly journals Interleaved-MIMO DAS for Indoor Radio Coverage: Guidelines for Planning

2014 ◽  
Vol 2014 ◽  
pp. 1-10
Author(s):  
E. M. Vitucci ◽  
F. Fuschini ◽  
V. Degli-Esposti ◽  
L. Tarlazzi
Keyword(s):  
Radio Channel ◽  
Multiple Input Multiple Output ◽  
Channel Measurements ◽  
Deployment Strategy ◽  
Indoor Coverage ◽  
Indoor Radio ◽  
Multiple Input ◽  
Input Multiple Output ◽  
Coverage Extension ◽  
The Impact

The combination of distributed antenna systems (DAS) and multiple input multiple output (MIMO) schemes opens the way to a variety of coverage solutions for indoor environment. In this paperinterleaved-MIMO (i-MIMO) DASindoor coverage extension strategies are studied. Their performance in high-order MIMO cases is investigated in realistic conditions through LTE-A link-level simulations, based on statistical data extracted from radio channel measurements; the impact of the deployment strategy on performance is then evaluated and useful planning guidelines are derived to determine the optimum deployment for a given propagation environment.

scholarly journals On the Effect of Different Grips of Handsets on Data Rate in the Measured Channels

2015 ◽  
Vol 2015 ◽  
pp. 1-8
Author(s):  
Maryam Rahimi ◽  
Ehsan Foroozanfard
Keyword(s):  
Multiple Input Multiple Output ◽  
Data Rate ◽  
Mimo Channels ◽  
Single Output ◽  
Measurement Results ◽  
Multiple Input ◽  
Input Multiple Output ◽  
The Impact ◽  
The City

The investigation on the achieved data rate of the cellular system considering different grips of handsets at different frequencies using measurement results of the measurement campaign—which was carried out in the city of Aalborg—is presented in this paper. The achieved data rate of the multiple-input single-output (MISO) interference channel is investigated. A typical propagation environment using two BSs and four handsets, like smart phones, held by four to eight different users was designed and multiple-input multiple-output (MIMO) channels in different scenarios were measured. In this paper, two BSs and two handsets at each measurement time are considered. The impact of the different parameters like correlation, different grips of handsets, and different long term evolution (LTE) frequency bands on the achieved data rate is investigated for different measurements. It could be concluded that the variations in the values of data rate are weakly associated with the different grips of handsets but more correlated with different frequencies.

Performance Enhancement of HAP-Based Relaying M-PPM FSO System Using Spatial Diversity and Heterodyne Detection Receiver

2018 ◽  
Vol 0 (0) ◽  
Author(s):  
Nga T.T. Nguyen ◽  
Minh Q. Vu ◽  
Hien T.T. Pham ◽  
Bac H. Dang ◽  
T. Dang Ngoc
Keyword(s):  
Performance Enhancement ◽  
Multiple Input Multiple Output ◽  
Relay Node ◽  
Local Oscillator ◽  
Spatial Diversity ◽  
Heterodyne Detection ◽  
Free Space Optical ◽  
Multiple Input ◽  
Input Multiple Output ◽  
The Impact

Abstract In this paper, we investigate the performance of a high-altitude platform (HAP)-based relaying free-space optical communication (FSO) system, where HAP plays a role as a relay node that employs detect-and-forward relaying scheme to connect between two ground stations (GSs). $M$ -ary pulse-position modulation (PPM), spatial diversity, and heterodyne detection receiver are used to improve the system’s performance. Instead of using multiple-input multiple-output (MIMO), which makes the HAP complex, multiple-input single-output (MISO) is applied to the uplink while single-input multiple-output (SIMO) is utilized for the downlink. Consequently, the HAP only needs a couple of transmit and receive aperture. The expression for the bit error rate (BER) of the proposed FSO system is derived considering the impact of atmospheric attenuation and turbulence. The achievable BER with low values has proved the feasibility of our proposed system. In addition, the advantages of using $M$ -PPM, spatial diversity, and heterodyne detection are demonstrated in terms of the power gain and the geometric distance between two GSs. Other useful information for system design regarding the required transmitted power, the number of transmit/receive apertures, the modulation level, and the local oscillator power is also provided in this paper.

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