Optimal Target Function for the Fractional Fourier Transform of LFM Signals

Xiao, Bo; Wang, Chunyang

doi:10.1007/s00034-022-01977-w

Cited by 5 publications

(3 citation statements)

References 17 publications

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“…According to the characteristics that the polyphase encoded signals present as a series of equally spaced impulses in the transformation domain uv − ( ), namely, in the FRFT spectrum, the objective function that can more prominently highlight the peak value of the impulses, should be selected. Here, the maximum amplitude (max-AM) [27] , the fourth-order origin moment (fourth-order OMFrS) [20] , and the information entropy (IE-FRFT) [18] are selected as the objective functions, and their mathematical definitions are shown as follows ( )…”

Section: Selection Of the Objective Functionmentioning

confidence: 99%

“…Regarding the study of the objective function of the parameter estimation algorithm, for LFM signals, information entropy was proposed as the objective function in literature [18], and the Otsu detection method was proposed in literature [19], but both performed poorly in low signal-to-noise ratio (SNR) environments. Literature [20][21] proposed the fourth-order origin moment as the objective function for single and multicomponent LFM signals respectively, and the results of parameter estimation through simulation experiments were good.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Parameter estimation of polyphase coded radar signal based on FRFT

Dong,

Chen,

Sun

et al. 2023

Preprint

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Due to the complex intra-pulse modulation of polyphase code signals, most research on intra-pulse parameter estimation algorithms has focused on utilizing techniques such as the Wigner Hough transform (WHT), Radon Wigner transform (RAT), and other methods. In this paper, we studied the fractional Fourier transform (FRFT) normalized spectrum of polyphase coded signals and derived a mathematical model to prove the impulse characteristic of the polyphase coded spectrum under optimum order. This is the theoretical basis for the fourth-order origin moment as the objective function, and an algorithm based on FRFT is proposed to estimate the intra-pulse parameters of polyphase coded signals. Through simulation experiments, it was shown that the algorithm has a good parameter estimation effect and low computational time, making it suitable for engineering practice. Furthermore, considering the difficulty in obtaining prior information on parameters in non-cooperative environments, which leads to the inapplicability of evaluation standard such as mean square error (MSE), we proposed an evaluation standard for parameter estimation based on a posteriori models. Through simulation experiments, this standard was proven to be as persuasive as MSE.

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Section: Selection Of the Objective Functionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Parameter estimation of polyphase coded radar signal based on FRFT

Dong,

Chen,

Sun

et al. 2023

Preprint

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“…The linear frequency modulated (LFM) signal is a commonly used nonstationary signal that has ideal energy accumulation features in the time-frequency plane. In this context, the DOA estimation algorithms based on the covariance matrix suffer from performance degradation due to the inability to express the time-frequency domain characteristics of the LFM signal [5][6][7]. Time-frequency (TF) analysis is an important method to process nonstationary signals, so people try to combine the time-frequency analysis method into the DOA estimation algorithm.…”

Section: Introductionmentioning

confidence: 99%

Kernel Function-Based Ambiguity Function and Its Application on DOA Estimation in Impulsive Noise

Dou

2022

Sensors

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To solve the problem that the traditional ambiguity function cannot well reflect the time-frequency distribution characteristics of linear frequency modulated (LFM) signals due to the presence of impulsive noise, two robust ambiguity functions: correntropy-based ambiguity function (CRAF) and fractional lower order correntropy-based ambiguity function (FLOCRAF) are defined based on the feature that correntropy kernel function can effectively suppress impulsive noise. Then these two robust ambiguity functions are used to estimate the direction of arrival (DOA) of narrowband LFM signal under an impulsive noise environment. Instead of the covariance matrix used in the ESPRIT algorithm by the spatial CRAF matrix and FLOCRAF matrix, the CRAF-ESPRIT and FLOCRAF-ESPRIT algorithms are proposed. Computer simulation results show that compared with the algorithms only using ambiguity function and the algorithms only using the correntropy kernel function-based correlation, the proposed algorithms using ambiguity function based on correntropy kernel function have good performance in terms of probability of resolution and estimation accuracy under various circumstances. Especially, the performance of the FLOCRAF-ESPRIT algorithm is better than the CRAF-ESPRIT algorithm in the environment of low generalized signal-to-noise ratio and strong impulsive noise.

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