scholarly journals “Three Crossings” Compensations of the High Speed Moving MIMO Radar

2014 ◽  
Vol 2014 ◽  
pp. 1-7
Author(s):  
Cheng Luo ◽  
Zishu He
Keyword(s):  
Fourier Transform ◽  
Antenna Array ◽  
High Speed ◽  
Fractional Fourier Transform ◽  
Mimo Radar ◽  
Compensation Method ◽  
Moving Target ◽  
Space Model ◽  
Working Model ◽  
Range Cell

The problems of the “Three Crossings” motions and compensations for the moving target of the high speed moving MIMO radar are studied. Firstly, the space model is established to describe the problems by educing the equations of delay and transmitting pattern, which are changing with time. The echo characteristics are analyzed and the formulas of the “Three Crossings” are given. Secondly, a compensation method, which uses the fractional Fourier transform (FrFT) to compensate the crossing Doppler-cell and the preprocess to compensate the crossing range-cell and crossing-beam, is proposed. This method could compensate the “Three Crossings” simultaneously with little complexity of calculation because the preprocess deals only with the transmitting signals. Lastly, the phantom antenna array is employed in the simulations, the working model of “sparse transmitting dense receiving” is applied to the simulation of crossing-beam, and the results of simulations demonstrate the validity and the practicability of the method of combining the preprocess and the FrFT to compensate “Three Crossings.”

A Particle Fuzzy Decisive Framework for Moving Target Detection in the Multichannel SAR Framework

2020 ◽  
Vol 19 (04) ◽  
pp. 2050032
Author(s):  
Eppili Jaya ◽  
B. T. Krishna
Keyword(s):  
Fourier Transform ◽  
Target Detection ◽  
Fuzzy System ◽  
Target Location ◽  
Fractional Fourier Transform ◽  
Moving Target ◽  
Detection Time ◽  
Moving Target Detection ◽  
Genetic Fuzzy System ◽  
Linguistic Rules

Target detection is one of the important subfields in the research of Synthetic Aperture Radar (SAR). It faces several challenges, due to the stationary objects, leading to the presence of scatter signal. Many researchers have succeeded on target detection, and this work introduces an approach for moving target detection in SAR. The newly developed scheme named Adaptive Particle Fuzzy System for Moving Target Detection (APFS-MTD) as the scheme utilizes the particle swarm optimization (PSO), adaptive, and fuzzy linguistic rules in APFS for identifying the target location. Initially, the received signals from the SAR are fed through the Generalized Radon-Fourier Transform (GRFT), Fractional Fourier Transform (FrFT), and matched filter to calculate the correlation using Ambiguity Function (AF). Then, the location of target is identified in the search space and is forwarded to the proposed APFS. The proposed APFS is the modification of standard Adaptive genetic fuzzy system using PSO. The performance of the MTD based on APFS is evaluated based on detection time, missed target rate, and Mean Square Error (MSE). The developed method achieves the minimal detection time of 4.13[Formula: see text]s, minimal MSE of 677.19, and the minimal moving target rate of 0.145, respectively.

scholarly journals Virtual Antenna Array and Fractional Fourier Transform-Based TOA Estimation for Wireless Positioning

Sensors ◽  
2019 ◽  
Vol 19 (3) ◽  
pp. 638 ◽  
Author(s):  
Zhigang Chen ◽  
Lei Wang ◽  
Mengya Zhang
Keyword(s):  
Fourier Transform ◽  
Antenna Array ◽  
Space Dimension ◽  
Fractional Fourier Transform ◽  
Phase Variation ◽  
Quadratic Function ◽  
Estimation Methods ◽  
Energy Concentration ◽  
Time Of Arrival ◽  
Toa Estimation

In this paper, a novel virtual antenna array and fractional Fourier transform (FRFT)-based 2-dimension super-resolution time-of-arrival (TOA) estimation algorithm for OFDM WLAN systems has been proposed. The proposed algorithm employs channel frequency responses (CFRs) at the equi-spaced positions on a line or quasi-line moving trajectory, i.e., the CFRs of a virtual antenna array, to extract multipaths’ TOA information. Meanwhile, a new chirp-like quadratic function is used to approximate the channel multipaths’ phase variation across the space dimension, which is more reasonable than the traditional linear function, especially for relatively big virtual antenna array sizes. By exploiting the property of chirp-like multipaths’ energy concentration in the FRFT domain, the FRFT can be first used to separate chirp-like multipath components, then the existing TOA estimation methods in frequency domain can be further employed on the separated multipath components to obtain the multipaths’ TOA estimates. Therefore, the proposed algorithm can make more use of the multipaths’ characteristics in the space dimension, thus it can efficiently enhance the multipath resolution and achieve better multipaths’ TOA estimation performance without requiring a real antenna array. Simulation results demonstrate the effectiveness of the proposed algorithm.

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