Combined bispectrum-filtering techniques for radar output signal reconstruction in ATR applications

Abstract

In automatic target recognition applications, an important task is to obtain denoised signal signatures of the object. In this paper, the reconstruction of 1-D deterministic signals, for example, range profiles, corrupted by random signal shift and additive white Gaussian noise using 2-D bispectrum is considered. Combined bispectrum-filtering techniques based on smoothing the noisy bispectrum estimates by 2-D linear and nonlinear filters are proposed. It is shown that bispectrum estimates obtained by the conventional direct bispectrum estimator are corrupted by fluctuation errors and are biased. The performance of the proposed bispectrum-based signal reconstruction methods is analysed using two conventional criteria -the reconstructed signal fluctuation variance and bias. The numerical simulation results show that 2-D filtering of real and imaginary components of noisy bispectrum estimates is most efficient in the sense of minimum MS errors.

Performance Study of Adaptive Filtering in Bispectrum Signal Reconstruction

“…As has been demonstrated in [21], filtering of the real and imaginary parts of the bispectrum is preferable to magnitude and phase bispectrum filtering. One can expect that filtering the real and imaginary parts of the Fourier spectrum recovered from the bispectrum can also be more effective than filtering the recovered magnitude and phase spectra.…”

“…Although, most papers on bispectrum analysis consider the high-SNR case [6], [18], the results presented in [11], [20], [21] have demonstrated that the bispectrum methods can be effectively used in the low-SNR case also.…”

“…One of the recently proposed approaches to solve this problem for data corrupted with heavy noise is the combined bispectrum filtering developed in [11], [20], [21], including the filtering of a two-dimensional (2D) bispectrum using scalar [21] and vector [11] filters, and filtering of one-dimensional (1D) phase and magnitude Fourier spectra recovered from the bispectrum [20]. Despite promising results that have been demonstrated in [11], [20], [21], some important questions have not been studied yet.…”

“…Despite promising results that have been demonstrated in [11], [20], [21], some important questions have not been studied yet.…”

Application of Triple Correlation and Bispectrum for Interference Immunity Improvement in Telecommunications Systems

“…Our strategy is based on the application of such properties of triple correlation and bispectrum that are widely employed in digital signal processing for solving problems of the detection and recovery of non-Gaussian processes embedded in additive Gaussian noise for radar systems (Totsky et al, 2003), bispectrum-based signal reconstruction in noisy environments (Totsky et al, 2006), biomedical engineering (Nakamura, 1993), and many other applications (Nikias and Raghuveer, 1987).…”